Bibliographie : Propriétés antivirales et antibactériennes d’Artemisia afra Jacq.

Artemisia et Coronavirus

Cet article présente et permet l’accès aux recherches publiées relatives aux propriétés antibactériennes, antivirales, immunomodulatrices et immunoprotectrices d’Artemisia afra et de ses principes actifs. Les études et leurs résumés sont présentés selon la chronologie de leur publication.

1997

Tonia Rabe & Johannes van Staden
Antibacterial activity of South African plants used for medicinal purposes.
Journal of Ethnopharmacology, March 1997, Volume 56, Issue 1, Pages 81-87

Antibacterial activity of South African plants used for medicinal purposes

Abstract

Crude extracts from 21 South African medicinal plants, traditionally used for ailments of an infectious or septic nature, were screened for in vitro antibacterial activity using the agar diffusion and dilution methods. Almost all the activity exhibited was against Gram-positive bacteria, with 12 of the 21 plant species tested showing some activity against Bacillus subtilis. Only the Warburgia salutaris methanol extract inhibited the growth of Escherichia coli. None of the extracts had any activity against Klebsiella pneumoniae. The highest activity was found in the methanol extracts from Bidens pilosa, Psidium guajava, Artemisia afra and Warburgia salutaris. The majority of the antibacterial activity was present in the methanolic, rather than the aqueous extracts.

1998

Renxiang Tan, Wei Zheng, H Q Tang
Biologically active substances from the genus Artemisia
Planta medica 1998

Biologically active substances from the genus Artemisia

Abstract

Artemisia species, widespread in nature, are frequently utilized for the treatment of diseases such as malaria, hepatitis, cancer, inflammation, and infections by fungi, bacteria, and viruses. Furthermore, some Artemisia constituents were found to be potential insecticides and allelopathic chemicals. This genus is receiving growing attention presumably due to : (i) the diversified biology and chemistry of the constituents, (ii) the frequent application in traditional medical practice, and (iii) the rich source of the plant material. This review summarizes mainly the biological results obtained in the past decade. The significance and trends in this field are briefly discussed.

1999

Mangena T, Muyima NY
Comparative evaluation of the antimicrobial activities of the essential oil of Artemisia afra, Pteronia incana and Rosmarinus officinalis on selected bacteria and yeast strains
Letters in Applied Microbiology, April 1999, Volume 28, Issue 4, Pages 291-296

Comparative evaluation of the antimicrobial activities of essential oils of Artemisia afra, Pteronia incana and Rosmarinus officinalis on selected bacteria and yeast strains

Abstract

Essential oils are frequently used for flavour and fragrance in the perfume, pharmaceutical, cosmetic and food industries. The antimicrobial activities of the essential oils of Artemisia afra, Pteronia incana and Rosmarinus officinalis were tested against 41 microbial strains. The test organisms were selected on the basis of their significance as food spoilage and/or poisoning, common human and plant pathogens. The agar diffusion assay was performed using nutrient agar and antibiotic medium. All the oils tested displayed some antimicrobial activities. However, the efficiency differed and depended both on the type and concentration of the oil, as well as the test microbial strain. Artemisia afra and R. officinalis showed similar and higher antimicrobial activity than P. incana. Due to their broad antimicrobial activities, the essential oils of the above plants growing in Eastern Cape may have preservative potential for the food and cosmetic industries.

2000

L.J. McGaw, A.K. Ja¨ger, J. van Staden
Antibacterial, anthelmintic and anti-amoebic activity in South African medicinal plants
Journal of Ethnopharmacology, 72 (2000), 247–263

Antibacterial, anthelmintic and anti-amoebic activity in South African medicinal plants

Abstract

Hexane, ethanol and water extracts of plants used by South African traditional healers for treating stomach ailments were screened for antibacterial, anthelmintic and anti-amoebic activities. To evaluate antibacterial activity, the disc-diffusion assay was used against several Gram-positive and Gram-negative species. Minimal inhibitory concentration values were determined with a microdilution assay. Ethanolic extracts showed the greatest activity, and Gram-positive bacteria were the most susceptible microorganisms. The free-living nematode Caenorhabditis elegans was used in two different assays to evaluate anthelmintic activity. A microdilution technique was employed to investigate anti-amoebic activity against the enteropathogenic Entamoeba histolytica. These assays were suitable for the screening of a large number of extracts at one time. Several plants exhibited significant activity against these test organisms.

Keywords : Antibacterial ; Anthelmintic ; Anti-amoebic ; South Africa ; Traditional medicine

2001

Dr K. Asres F. Bucar T. Kartnig M. Witvrouw C. Pannecouque E. De Clercq
Antiviral activity against human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) of ethnobotanically selected Ethiopian medicinal plants
Phytotherapy Research, January 2001, Volume 15, Issue 1

Antiviral activity against human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) of ethnobotanically selected Ethiopian medicinal plants

Abstract

Ethiopian medicinal plants used for the treatment of a variety of ailments including infectious diseases were screened for activity against human immunodeficiency virus type 1 (HIV‐1) and type 2 (HIV‐2). Seventy‐one polar and nonpolar extracts derived from 21 plants belonging to 14 families were tested for inhibition of viral replication using HIV‐1 (IIIB) and HIV‐2 (ROD) strains. Selective inhibition of viral growth was assessed by the simultaneous determination of the in vitro cytotoxicity of each of the extracts against MT‐4 cells. Six extracts made from the root bark of Bersama abyssinica Fresen, the leaves of Combretum paniculatum Vent., and Dodonaea angustifolia L.f., and the stem bark of Ximenia americana L. displayed antiviral activity at concentrations that were nontoxic to MT‐4 cells. The highest selective inhibition of HIV‐1 replication was observed with the acetone fraction of C. paniculatum and the methanol fraction of D. angustifolia which showed selectivity indices (ratio of 50% cytotoxic concentration to 50% effective antiviral concentration) of 6.4 and 4.9, and afforded cell protection of viral induced cytopathic effect of 100% and 99%, respectively, when compared with control samples. The greatest degree of antiviral activity against HIV‐2 was achieved with the acetone extract of C. paniculatum (EC50 : 3 µg/mL), which also showed the highest selectivity index (32). The 50% cytotoxic concentration ranged from 0.5 µg/mL for the hexane extract of D. angustifolia L.f., the most cytotoxic of the extracts tested, to >250 µg/mL for some extracts such as the methanol fraction of Alcea rosea L., the least toxic tested. Only the polar extracts that were obtained by extraction with hydroalcohol, methanol or acetone exhibited inhibition of viral growth at subtoxic concentrations. The results obtained in this study enable the selection of extracts which show some specificity of action and support the further investigation of these extracts for their potential as new lead antiretroviral compounds. Copyright © 2001 John Wiley & Sons, Ltd.

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M. Burits ; K. Asres ; F. Bucar
The antioxidant activity of the essential oils of Artemisia afra, Artemisia abyssinica and Juniperus procera
Phytotherapy Research, volume 15, issue 2 (2001)

The Antioxidant Activity of the Essential Oils of Artemisia afra, Artemisia abyssinica and Juniperus procera

The essential oils of Artemisia afra Jacq., Artemisia abyssinica Schultz-Bip. and Juniperus procera Hoechst ex Endl. were examined for their potential radical scavenging activities. First a rapid evaluation of antioxidants was made using a TLC screening method. The abilities of the volatile oils to act as nonspecific donors for hydrogen atoms or electrons were checked in the diphenylpicrylhydrazyl assay. Oils from all three species showed positive results and were examined further. The oils of A. afra and J. procera were also effective hydroxyl radical scavenging agents when assessed in the deoxyribose degradation assay, whilst oils from A. abyssinica exhibited a paradoxical effect. In the in vitro assay for non-enzymatic lipid peroxidation in liposomes, the oils of A. afra and J. procera also displayed antioxidant potential. It was not possible to measure the effect of A. abyssinica oil in this system because certain components, e.g. alk2-enals, interfered with the assay. The compounds that contribute to the radical scavenging activities of A. afra and J. procera were identified and then assessed for their effects in the various test systems. Finally, the qualitative and quantitative compositions of the essential oils were studied by GC-MS.

Keywords : Artemisia afra ; Artemisia abyssinica ; Juniperus procera ; essential oils ; antioxidant activity ; GC-MS-analysis.

2002

Ntutela, Siyabulela Calvin Sibusiso
In vitro efficacy tests against Mycobacterium species of South African traditional medicinal plants
Thesis Published by the University of Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author.

In vitro efficacy tests against Mycobacterium species of South African traditional medicinal plants

Abstract :

Problem statement : Tuberculosis is the leading cause of death due to a single organism ; with a mortality of more than 3 million people each year, worldwide. The emergence of multi-drug resistance and HIV] AIDS are the major causes of this problem. New therapeutic agents with a different mode of action, and thereby of resistance to Mycobacterium tuberculosis, the causative agent, are needed urgently. Among the methods used, the area of ethnopharmacology is explored in this study.

Methods : Visits were performed to collect the plants used by traditional healers in 7 provinces of South Africa for the treatment of tuberculosis. Extracts from the plants were tested against M. aurum A+, in vitro, using firefly luciferase bioluminescence assay at 200 pg/rnl concentrations. Active extracts were further tested against M. tuberculosis H37Rv, in vitro. Isolated compounds were tested against 5 clinical strains of M. tuberculosis using the BACTEC 460 TB system. Cytotoxicity testing was performed using MTT assay against Chinese hamster ovarian cell lines.

Results : A total of 24 plants were collected. The dichloromethane extracts of Artemisia afra Jacq (Asteraceae) showed the highest activity against M. durum A‘ and M. tuberculosis H37-Rv with ICSO of 270 pg/ml and 290 pg/ml, respectively. Further fractionation of the plant yielded two sesquiterpene lactones of eudesmanolide type, tanacetin and artemin/arsubin, with molecular weights of 264 g/mol and 266 g/mo], respectively. The biological assay of a mixture of the two sesquiterpenes showed an in vitro activity against M. aurum A+ and M. tuberculosis H31-Rv, with IC5@ of 1.9 pg/ml and 2.0 pg/ml, respectively. The sesquiterpenes had an IC5@ of 20.5 pg/ml against Chinese hamster ovarian cells, compared to daunomycin, with an IC5@ of 3.5 pg/ml.

Conclusions : The crude dichloromethane extract of A. afra was active against M. aurum A+, in vitro. The isolated sesquiterpene lactones were also active against M. tuberculosis H3 ;-Rv and some clinical strains of mycobacteria. The sesquiterpenes were not cytotoxic against Chinese hamster ovarian cells. The study reports on the finding of these visits to the traditional healers and on the biological assays performed to validate the activity of the two sesquiterpenes.

Theses / Dissertations > PhD / Doctoral

Abstract :

Tuberculosis is the leading cause of death due to a single organism ; with a mortality of more than 3 millions people each year, worldwide. The emergence of multi-drug resistance and HIV/AIDS are the major causes of this problem. New therapeutic agents with a different mode of action, and thereby of resistance to Mycobacterium tuberculosis, the causative agent, are needed urgently. Amongst the methods used, the area of ethnopharmacology is explored in this study. Visits were performed to collect the plants used by traditional healers in 7 provinces of South Africa for the treatment of tuberculosis

2003

Lehlohonolo Tebogo Gwebu
The antimicrobial activity and phytochemistry of african wormwood (artemisia afra)
Research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Masters of Science in Medicine (Pharmaceutical Affairs). Johannesburg, 2003

The antimicrobial activity and phytochemistry of african wormwood (artemisia afra)

Abstract

Artemisia afra Jacq. Wild also known as African wormwood, “umhlonyane” (Xhosa and Zulu), “lengana” (Sotho and Tswana) and “wildeals” (Afrikaans) is an aromatic shrub belonging to the Asteraceace. It is widespread in South Africa extending from the mountainous regions of the South Western Cape, along the eastern coast to the Northern Province (van Wyk et al., 1997). Due to the popular use of A. afra, herbal tinctures have been prepared for commercial distribution. As the chemotypic variation remains unrecorded it has been impossible to standardize extracts containing A. afra. The aerial parts of sixteen samples from four natural populations were hydrodistilled and the essential oil analysed by GC-MS and tested for antimicrobial activity on a number of bacteria and fungi. The essential oil composition varied quantitatively and qualitatively within and between natural populations. With the aid of cluster analysis, several chemotypes have been identified based on the presence and quantity of the following compounds ; a-thujone (5.55-77.65%), (3-thujone (1.37-57.73%), camphor (1.00-48.99%), 1.8-cineole (2.31-50.09%), artemisia ketone (14.47-27.97%), artemisia alcohol (9.31- 27.76%) and santolinyl acetate (4.14-24.32%). The variation did not correlate to geographical distribution. The essential oil of all the plants was active against all organisms studied except Pseudomonas aeruginosa and Enterococcus facaelis. The oil exhibited higher antifungal properties than antibacterial activity. The pure terpene standards of major compounds detected in A. afra (thujone, cineole, camphor etc.) showed no antimicrobial activity and it can be assumed that the oil could exert antimicrobial properties by working in a synergistic way. Artemisia afra varies within and between natural populations and standardizing of commercial products will be problematic without cloning of a favourable chemotype. Selection of favourable chemotypes should be based on efficacy (i.e. wide spectrum anti-microbial activity) and safety index (e.g. low thujone content).

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Esameldin E. Elgorashi ; Joslyn L.S. Taylor ; Annemarie Maes ; Johannes van Staden ; Norbert De Kimpe ; Luc Verschaeve
Screening of medicinal plants used in South African traditional medicine for genotoxic effects
Toxicology Letters, volume 143, issue 2 (2003)

Screening of medicinal plants used in South African traditional medicine for genotoxic effects

Abstract

Dichloromethane and 90% methanol extracts from 51 South African medicinal plants were evaluated for potential genotoxic effects using the bacterial Ames and VITOTOX† tests with and without metabolic activation. Dichloromethane extracts from bulbs of Crinum macowanii showed mutagenicity in strain TA98 with and without metabolic activation, whereas extracts from leaves of Chaetacme aristata and foliage of Plumbago auriculata showed mutagenicity and/or toxicity. Extracts from the leaves of Catharanthus roseus and twigs of Combretum mkhzense were mutagenic with metabolic activation only. The only 90% methanol extracts that were mutagenic in strain TA98 were from the leaves of C. roseus and Ziziphus mucronata in the presence of metabolic activation. No genotoxic effects were found in strain TA100 or in the VITOTOX† test.

Keywords : Plant extracts ; Medicinal plants ; Genotoxicity ; Ames test ; VITOTOX† test

2007

Manuela Saddi, Adriana Sanna, Filippo Cottiglia, Lorenza Chisu, Laura Casu, Leonardo Bonsignore & Alessandro De Logu
Antiherpevirus activity of Artemisia arborescens essential oil and inhibition of lateral diffusion in Vero cells
Annals of Clinical Microbiology and Antimicrobials volume 6, Article number : 10 (2007)

Antiherpevirus activity of Artemisia arborescens essential oil and inhibition of lateral diffusion in Vero cells

Abstract

Background New prophylactic and therapeutic tools are needed for the treatment of herpes simplex virus infections. Several essential oils have shown to possess antiviral activity in vitro against a wide spectrum of viruses.

Aim The present study was assess to investigate the activities of the essential oil obtained from leaves of Artemisia arborescens against HSV-1 and HSV-2

Methods The cytotoxicity in Vero cells was evaluated by the MTT reduction method. The IC50 values were determined by plaque reduction assay. In order to characterize the mechanism of action, yield reduction assay, inhibition of plaque development assay, attachment assay, penetration assay and post-attachment virus neutralization assay were also performed.

Results The IC50 values, determined by plaque reduction assay, were 2.4 and 4.1 μg/ml for HSV-1 and HSV-2, respectively, while the cytotoxicity assay against Vero cells, as determined by the MTT reduction method, showed a CC50 value of 132 μg/ml, indicating a CC50/IC50 ratio of 55 for HSV-1 and 32.2 for HSV-2. The antiviral activity of A. arborescens essential oil is principally due to direct virucidal effects. A poor activity determined by yield reduction assay was observed against HSV-1 at higher concentrations when added to cultures of infected cells. No inhibition was observed by attachment assay, penetration assay and post-attachment virus neutralization assay. Furthermore, inhibition of plaque development assay showed that A. arborescens essential oil inhibits the lateral diffusion of both HSV-1 and HSV-2.

Conclusion This study demonstrates the antiviral activity of the essential oil in toto obtained from A. arborescens against HSV-1 and HSV-2. The mode of action of the essential oil as antiherpesvirus agent seems to be particularly interesting in consideration of its ability to inactivate the virus and to inhibit the cell-to-cell virus diffusion.

Excerpt

« Artemisia species are widespread in nature and are frequently employed for the treatment of several diseases such as malaria, hepatitis, cancer, inflammation and infections sustained by fungi or bacteria. In particular, A. annua is known as a remedy for various fevers including malaria and A. afra, A. giraldii and A. mexicana have been described for their antibacterial activity. »

2008

N.Q. Liu, F, Van der Kooy, R. Verpoorte
.Artemisia afra : A potential flagship for African medicinal plants ?
South African Journal of Botany 75 (2009) 185–195

Artemisia afra : A potential flagship for African medicinal plants ?

Abstract : The genus Artemisia consists of about 500 species, occurring throughout the world. Some very important drug leads have been discovered from this genus, notably artemisinin, the well known anti-malarial drug isolated from the Chinese herb Artemisia annua. The genus is also known for its aromatic nature and hence research has been focussed on the chemical compositions of the volatile secondary metabolites obtained from various Artemisia species. In the southern African region, A. afra is one of the most popular and commonly used herbal medicines. It is used to treat various ailments ranging from coughs and colds to malaria and diabetes. Although it is one of the most popular local herbal medicines, only limited scientific research, mainly focussing on the volatile secondary metabolites content, has been conducted on this species. The aim of this review was therefore to collect all available scientific literature published on A. afra and combine it into this paper. In this review, a general overview will be given on the morphology, taxonomy and geographical distribution of A. afra. The major focus will however be on the secondary metabolites, mainly the volatile secondary metabolites, which have been identified from this species. In addition all of the reported biological activities of the extracts derived from this species have been included as well as the literature on the pharmacology and toxicology. We aim at bringing together most of the available scientific research conducted on this species, which is currently scattered across various publications, into this review paper.

Keywords : Artemisia afra ; Traditional African Medicine ; Volatile secondary Metabolites

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Harun A. Omer
Preparation of Artemisia to treat human cancer, autoimmune disease, IgA-Nephropathy, and to counteract weight loss in cancer patients
United States Patent Application Publication

Preparation of Artemisia to treat human cancer, autoimmune disease, IgA-Nephropathy, and to counteract weight loss in cancer patients

Abstract

In human cancer, reduced appetite and weight loss are serious symptoms and are difficult to manage. These symptoms not only effect the quality of life, but also reduce the tolerance and response to anti-cancer drugs, thereby effecting the prognosis and survival to disease. These symptoms are caused, among others, by overactive immune system of the body. Anti-cancer drugs that were effective in the beginning start losing their efficacy, and are less tolerated. Also in autoimmune diseases, the immune system is overreacting. This herbal invention, based on Artemisia species, ginger root and large cardamom, each targeting at different factors involved in weight loss and autoimmune diseases, is effective in improving appetite, thus counteracts the development of resistance to anti-cancer drugs, and helps in the cure of autoimmune diseases, IgA-Nephropathy, which has no cure so far.

2009

Ryno Freidberg
An investigation into the antimicrobial and anticancer activities of Geranium incanum, Artemisia afra and Artemisia absinthium
Submitted in partial fulfillment of the requirements for the degree of Magister Technologiae Biomedical Technology in the Faculty of Health Science at the Nelson Mandela Metropolitan University, 2009

An investigation into the antimicrobial and anticancer activities of Geranium incanum, Artemisia afra and Artemisia absinthium

Summary

It has been estimated that between 3000 and 4000 plant species are used for their medicinal properties throughout South Africa, with approximately 27 million South Africans making use of traditional medicines. Of this 27 million, 3 million South Africans rely on traditional medicine as their primary source of health care. Of the 250 000 to 500 000 known plant species, very few have been investigated for their pharmacological qualities, and compounds of significant medicinal value may still remain undiscovered in many plant species. The aims of this study included investigating the antimicrobial properties of Geranium incanum and Artemisia afra, both plants traditionally used for their medicinal properties, and comparing the antimicrobial activity of the latter to that of Artemisia absinthium, as well as investigating the anticancer properties of G. incanum and A. afra, and comparing the anticancer activity of the latter to that of A. absinthium. Infusions, aqueous-, methanol- and acetone extracts of the three plants were prepared and used for anticancer and antimicrobial screening. Plant specimens used to prepare extracts for antimicrobial activity were collected and extracted over three seasons, while extracts used for anticancer screening were prepared from plants collected during the summer only. Considerable variation existed in the percentage crude extract yields obtained when different extractants were used, while the season in which the plants were harvested and extracted also appeared to play a significant role in the amount of extract obtained. The plant extracts were screened for antimicrobial activity against various strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus and Bacillus cereus, using an agar dilution method. G. incanum and A. afra possessed activity for C. albicans, while all three plants showed activity for S. aureus and B. cereus. Activity was largely dependent on the extraction method used. iii The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was used to screen for anticancer activity of the respective extracts, at varying concentrations, against MCF-7 (human breast adenocarcinoma) cells, HT-29 (human colonic adenocarcinoma) cells and HeLa (human cervical cancer) cells. All of the extracts showed cytotoxic activity in all three cell lines to varying extents, depending on the extract used and cell line screened. The acetone extract of A. afra proved to be the most effective inhibitor with the lowest IC50 (2.65 ± 1.05 µg/ml) having been shown in MCF-7 cells. A. afra and A. absinthium showed similar inhibitory patterns, with the methanol- and acetone extracts having been the most potent inhibitors of each of the respective cell lines in general. Fluorescence microscopy employing 4’,6-diamidino-2-phenylindole dihydrochloride (DAPI) and propidium iodide (PI) staining indicated that the acetone extract of A. afra induces apoptosis in MCF-7 cells as apposed to necrosis, and the results were comparable to those obtained for cells exposed to cisplatin. Screening of the A. afra acetone extract for toxicity in normal human cells using the CellTiter-Blue® assay indicated the extract to be toxic to peripheral blood mononuclear cells (PBMC’s) at concentrations comparable to that for MCF-7 cells, while cell cycle analysis of MCF-7 cells exposed to the A. afra acetone extract indicated the extract’s ability to induce apoptosis comparable to that of cisplatin, with the extract exerting its activity at a point during or just prior to the S phase of the cell cycle.

Key words : anticancer, antimicrobial, apoptosis, Artemisia absinthium ; Artemisia afra ; Bacillus cereus ; Candida albicans ; cell cycle ; DAPI ; Enterococcus faecalis ; Escherichia coli ; Geranium incanum ; HeLa ; HT-29 ; IC50 ; MCF-7 ; MTT ; peripheral blood mononuclear cells ; PI ; Pseudomonas aeruginosa ; Staphylococcus aureus ; traditional medicines

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Lisa Buwa & Anthony Jide Afolayan
Antimicrobial activity of some medicinal plants used for the treatment of tuberculosis in the Eastern Cape Province, South Africa
African Journal of Biotechnology, December 2009, Vol. 8 (23), pp. 6683-6687

Antimicrobial activity of some medicinal plants used for the treatment of tuberculosis in the Eastern Cape Province, South Africa

Abstract :

Artemisia afra Jacq. Ex Willd., Carpobrotus edulis L. and Tulbaghia violacea Harv. were screened for activity against Bacillus cereus, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Mycobacterium aurum A+ strain using a two-fold microdilution bioassay. M. aurum is tuberculosis (TB) related strain that was used in this study. These plants were selected based on their use by South African traditional healers for the treatment of TB and symptoms of the disease. All three plants were extracted with water, ethanol and dichloromethane. The extracts of A. afra were found to be active against all the tested microorganisms. Only in the instance of A. afra and C. edulis did water extract show activity against M. aurum A+ strain. The ethanol extract of C. edulis showed very good activity against the Gram-positive bacteria only. Dichloromethane extracts of T. violacea were found to be highly active against all the microorganisms, except for K. pneumoniae.

Keywords : Medicinal plants, tuberculosis, antibacterial activity, Mycobacterium aurum.

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Seo, Jung-Ah, Kim, Jae-Gon, Kim, Mi-Ah, Baik, Byeong-Ju, Yang, Yeon-Mi, Jeong, Jin-Woo
Antimicrobial Activity of Artemisia Species against Clinically Isolated Streptococcus Mutans
The Journal of The Korean Academy Of Pediatric Dentistry, 2009, Volume 36 Issue 4, Pages.505-513

Antimicrobial Activity of Artemisia Species against Clinically Isolated Streptococcus Mutans

Abstract

Streptococcus mutans plays a major role in the formation of dental plaque and it is considered one of the important pathogens in the development of dental caries. Established dental plaque can be more resistant to antimicrobial agents and offers nutrient rich and relatively stable cariogenic conditions for bacteria. Thus bacteria growing in dental plaque have strong resistance to antimicrobial agents and they are not removed easily by the flow of saliva. Many researchers have been performed using natural materials, especially herbal extracts to prevent dental plaque. However, the strains of mutans streptococci used in the researches were not from Koreans. Therefore, it would be necessary to evaluate the antimicrobial activity of herbal extracts against clinical isolates of Streptococcus mutans isolated from saliva of Koreans living in Jeollabuk-do. For this study four clinical isolates were isolated from saliva samples of seventeen Korean people to investigate whether essential oils of Artemisia spp. have antimicrobial activity against them including four reference strains of Streptococcus mutans. Minimum inhibitory concentrations, Minimum bactericidal concentrations and time kill studies were performed and the results showed that Artemisia lavandulaefolia DC, Artemisia scoparia, and Artemisia capillaries have antimicrobial activity against the Streptococcus mutans clinical isolates and reference strains.

Keywords
Artemisia ; Antimicrobial agent ; Streptococcus mutans

2010

Yusra Kriel
The immune-modulating activity of Artemisia afra
Submitted in fulfillment of the requirement for the degree, Magister Scientiae (M.Sc) at the University of The Western Cape, South Africa

The immune-modulating activity of Artemisia afra

Abstract

The human immune system consists of innate and adaptive mechanisms of defence that protect the host from harmful substances. Cytokines and other immune components play an important role in the induction and regulation of these defence mechanisms. Despite these mechanisms, sometimes pathogens still manage to evade the immune system causing disease ; or allergens result in hypersensitive reactions ; or the immune system becomes overly sensitive and starts attacking the “self”. Irrespective of the cause, despite its best efforts, the immune system sometimes needs help regulating its defences. Artemisia afra is an indigenous member of the daisy or Asteraceae family. It is one of the oldest and most common plants used as a traditional medicine in South Africa. Because of the great diversity of ailments traditionally treated with Artemisia afra, it is considered a “cure-all”. The aerial parts contain various phenolic compounds that have anti-bacterial and anti-fungal activity. This helps to explain its popularity in treating bacterial infections such as sore throats, ear infections and various bronchial diseases. Other traditional uses include viral infections such as measles and influenza, and parasitic infections such as malaria and intestinal parasites. Non-pathogenic conditions traditionally treated with Artemisia afra include diabetes mellitus, gout and neuraligia, autoimmune conditions like rheumatoid arthritis and allergic conditions such as asthma. Due to this wide range of traditional indications, Artemisia afra is thought to have immune regulating effects. Herbal medications are becoming increasingly popular with the general public. Knowledge regarding indigenous medicines is very limited, while the need for such knowledge is becoming more essential. It is estimated that in Africa approximately 80 % of people rely on herbal medicine for primary health care. Most literature sources focus on the study of European herbs and medical practitioners are not well equipped to guide the public on issues vi relating to herbal medicines. Adverse and side effects of herbs become common when the herb is taken incorrectly or together with certain medications. Despite the wide variety of conditions traditionally treated with Artemisia afra, limited literature exists regarding the bioactivities on the species, and no immune studies have been done until now. The aim of this study was to use human whole blood cultures to examine Artemisia afra’s immunomodulating effects in vito. A 20 % (w/v) Artemisia afra extract was prepared using 94.4 % ethanol and milled aerial herb organs. The extract was air dried and re-suspended in DMSO to obtain a 50 % (wet leaf w/v) extract. Blood was collected from healthy male volunteers and diluted with RPMI1640. To measure inflammatory activity and cytotoxicity, stimulated blood contained 1 volume of 10 μg/ml LPS in DMSO, 10 volumes of blood and 89 volumes of RMPI-1640. Blood (200 μl/well) was added to various concentrations of Artemisia afra. This was incubated at 37 ºC for 24 hours. For cell-mediated and humoral immunity, stimulated blood contained 10 volumes of blood and 89 volumes of RPMI-1640 medium and 1 volume of 1.6 mg/ml PHA in RPMI-1640 and incubated for 48 hours. An LDH assay was used to analyse the herb for cytotoxicity and various ELISAs for cytokine analysis. IL-6 was used as a biomarker for inflammatory activity, IL-10 for humoral immunity and IFN-γ for cellmediated immunity. Results were statistically analysed using ANOVA tests. Results showed that Artemisia afra was significantly cytotoxic (P<0.050)>

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James T. Mukinda ; James A. Syce ; David Fisher ; Mervin Meyer
Effect of the plant matrix on the uptake of luteolin derivatives-containing Artemisia afra aqueous-extract in Caco-2 cells
Journal of Ethnopharmacology. 2010 Aug 9 ; 130(3) : 439-49.

Effect of the plant matrix on the uptake of luteolin derivatives-containing Artemisia afra aqueous-extract in Caco-2 cells

Abstract :

Aim of the study : Luteolin is a major flavonoid constituent and a primary candidate that might contribute to the claimed in vivo protective effects of Artemisia afra (Jacq. Ex. Willd). However, an exhaustive search yielded no literature evidence on the absorption, metabolism and fate of this flavonoid from the traditional plant preparation. The purpose of this study was to investigate the effect of the plant matrix on the uptake of luteolin derivatives from Artemisia afra aqueous extract in human intestinal epithelial Caco-2 cells.

Materials and methods : Cell monolayers were incubated with 5, 10 and 20 ?g/ml doses of luteolin aglycone, luteolin-7-0-glucoside, un-hydrolyzed or acid-hydrolyzed Artemisia afra extracts, and samples of 150 ?l each were collected from both apical and basolateral sides of cells at 30, 60 and 120min for HPLC and LC–MS analyses.

Results : After 1-h exposure, the uptake of luteolin aglycone and luteolin-7-0-glucoside from the unhydrolyzed and acid-hydrolyzed extracts was significantly faster and quantitatively higher (i.e. >77% vs. < 25% of the initial doses over the first 30min, p < 0.05) than that from non-plant solutions. Apical to basolateral permeability coefficients for luteolin and its-7-0-glucoside in the extracts were 1.6- to 2-fold higher than that for the non-plant solutions. Glucuronidation was an important pathway of metabolismfor luteolin in both non-plant and plant extract forms.

Conclusions : Luteolin in Artemisia afra aqueous extract, regardless of its form (i.e. whether aglycone and 7-0-glucoside), is taken up better and more efficiently metabolized than the aglycone and 7-0-glucoside forms administered as pure solutions in Caco-2 cells. Flavonoid actives from Artemisia afra plant extracts and especially traditionally prepared dosage forms may thus have better bioavailability, and consequently greater in vivo potency, than that predicted from studies done using the pure solutions

Keywords : Artemisia afra, Flavonoid, Luteolin, Glucosides, Transepithelial, transport, Caco-2 cells, Bioavailability

***

P. Bräunlich
Struktur- og aktivitetsstudier av polysakkarider isolert fra en sørafrikansk medisinplante : Artemisia afra
titre en français (traduit du Norvégien) :
Etudes de la structure et de l’activité de polysaccharides isolés d’une plante médicinale sud-africaine : Artemisia afra
English translation of title :
Structure and activity studies of polysaccharides isolated from a South African medicinal plant : Artemisia afra

Abstract

Artemisia afra er en velkjent medisinplante i Sor-Afrika og den brukes ved mange ulike indikasjoner som blant annet forkjolelse, malaria og ved sar. Det er gjort begrenset forskning pa A.afra og de fleste studier som har blitt utfort fokuserer pa innholdet av de flyktige, sekundaere metabolittene. Det er ikke gjort noe tidligere forskning pa polysakkarider fra denne medisinplanten. Polysakkarider fra planter kan ha immunmodulerende egenskaper og det er rimelig a anta at disse kan bidra til noen av de farmakologiske effektene assosiert med denne planten. Det er derfor interessant a utfore struktur- og aktivitetsstudier av polysakkarider isolert fra A. afra.
Torkede blader og stilker ble ekstrahert med organiske losemidler for a fjerne lavmolekylaere og upolare forbindelser. Polysakkaridene ble isolert ved ekstraksjon med etanol, 50°C og 100°C vann. Ekstraktene ble opprenset ved ionebytterkromatografi med ANX Sepharose 4 Fast Flow til de sure fraksjonene GradEtOH, GradI50, GradI100 og GradII100. Disse fraksjonene ble ytterligere separert pa en Sephacryl S-200 gelfiltreringskolonne til fraksjonene GradEtOHa, GradI50a, GradI100a og GradII100a. Disse ble enzymatisk degradert med endo-polygalakturonidase og de forgrenede omradene ble isolert ved gelfiltrering pa en PD-10 kolonne. Dette ga fraksjonene GradEtOHaE, GradI50aE, GradI100aE og GradII100aE. Etter isolering og fraksjonering ble det utfort karbohydratanalyser og biologisk aktivitet ble bestemt for de nevnte fraksjonene.

Analyse av karbohydratinnhold og bindingsforhold viste at alle fraksjoner inneholder monosakkarider som er typiske for pektiner. GradEtOHa, GradI50a og GradI100a inneholder trolig store omrader med rhamnogalakturonan I, mens det ble funnet at GradII100a inneholder betydelige mengder med homogalakturonan. Felling med Yariv reagens viste at GradEtOHa, GradI50a og GradI100a inneholder AG-II, men denne strukturenheten ble ikke pavist i GradII100a. Karbohydratinnholdet ble ogsa bestemt for de enzymatisk degraderte fraksjonene, og andelen av de ulike monosakkaridene for og etter enzymatisk degradering var i liten grad endret.
Komplementfikseringstesten var en metode som ble brukt for a undersoke biologisk aktivitet. De sure ekstraktene GradEtOH, GradI50, GradI100 og GradII100 hadde en bedre komplementfikserende aktivitet enn den positive kontrollen PMII.

De gelfiltrerte fraksjonene GradEtOHa, GradI50a, og GradI100a viste en nesten fem ganger hoyere antikomplementaer effekt enn PMII, mens GradII100a hadde noe hoyere aktivitet enn standarden. Komplementfikserende aktivitet ble ogsa bestemt for fraksjonene etter enzymatisk degradering, der GradEtOHaE, GradI50aE og GradI100aE viste hoy antikomplementaer effekt i forhold til standarden PMII, mens GradII100aE hadde en fire ganger lavere komplementfikserende aktivitet.

De gelfiltrerte fraksjonene ble undersøkt for makrofagstimulerende effekt. Prøven GradI100a ser ut til å inneha aktivitet i en konsentrasjon på 100 μg/ml. De resterende fraksjonene, GradEtOHa, GradI50a og GradII100a viste en betydelig lavere aktivitet enn PMII.

Aktiviteten på IL-6 ble bestemt for fraksjonene GradEtOH, GradI50, GradI100 og GradII100. Proinflammatorisk aktivitet har blitt observert for alle ekstrakter, men ingen av prøvene viste antiinflammatoriske egenskaper. På grunn av tidsmangel ble kun 2 av 8 donorer analysert, og man kan derfor ikke trekke noen endelige konklusjoner.

Traduction du résumé en français :

L’Artemisia afra est une plante médicinale bien connue en Afrique du Sud et elle est utilisée pour de nombreuses indications différentes telles que le rhume, le paludisme et les ulcères. Des recherches limitées ont été effectuées sur A. afra et la plupart des études qui ont été menées se concentrent sur la teneur en métabolites secondaires volatils. Aucune recherche antérieure n’a été effectuée sur les polysaccharides de cette plante médicinale. Les polysaccharides végétaux peuvent avoir des propriétés immunomodulatrices et il est raisonnable de supposer que ceux-ci peuvent contribuer à certains des effets pharmacologiques associés à cette plante. Il est donc intéressant de réaliser des études de structure et d’activité des polysaccharides isolés d’A. Afra.
Les feuilles et les tiges séchées ont été extraites avec des solvants organiques pour éliminer les composés de faible poids moléculaire et non polaires. Les polysaccharides ont été isolés par extraction avec de l’éthanol, 50 ° C et 100 ° C d’eau. Les extraits ont été purifiés par Chromatographie d’échange d’ions avec ANX Sepharose 4 Fast Flow vers les fractions acides GradEtOH, GradI50, GradI100 et GradII100. Ces fractions ont été en outre séparées sur une colonne de filtration sur gel Sephacryl S-200 en les fractions GradEtOHa, GradI50a, GradI100a et GradII100a. Celles-ci ont été dégradées par voie enzymatique avec l’endopolygalacturonidase et les régions ramifiées ont été isolées par filtration sur gel sur une colonne PD-10. Cela a donné les fractions GradEtOHaE, GradI50aE, GradI100aE et GradII100aE. Après isolement et fractionnement, des analyses de glucides ont été effectuées et l’activité biologique a été déterminée pour les fractions susmentionnées.
L’analyse de la teneur en glucides et du rapport de liaison a montré que toutes les fractions contiennent des monosaccharides typiques des pectines. GradEtOHa, GradI50a et GradI100a contiennent probablement de grandes gammes de rhamnogalacturonan I, alors qu’il a été constaté que GradII100a contient des quantités importantes d’homogalacturonan. La coagulation avec le réactif Yariv a montré que GradEtOHa, GradI50a et GradI100a contiennent AG-II, mais cette unité structurelle n’a pas été détectée dans GradII100a. La teneur en glucides a également été déterminée pour les fractions dégradées par voie enzymatique et la proportion des divers monosaccharides avant et après la dégradation enzymatique a été légèrement modifiée.
Le test de fixation du complément était une méthode utilisée pour étudier l’activité biologique. Les extraits acides GradEtOH, GradI50, GradI100 et GradII100 avaient une meilleure activité de fixation du complément que le contrôle positif PMII.
Les fractions filtrées sur gel de GradEtOHa, GradI50a et GradI100a ont montré un effet anti-complément presque cinq fois plus élevé que PMII, tandis que GradII100a avait une activité quelque peu plus élevée que la norme. L’activité de fixation du complément a également été déterminée pour les fractions après dégradation enzymatique, GradEtOHaE, GradI50aE et GradI100aE montrant une efficacité anticomplémentaire élevée par rapport au PMII standard, tandis que GradII100aE avait une activité de fixation du complément quatre fois inférieure.
Les fractions filtrées sur gel ont été examinées pour déterminer l’effet stimulant des macrophages.

Les fractions filtrées sur gel ont été examinées pour déterminer l’effet stimulant des macrophages. L’échantillon GradI100a semble avoir une activité à une concentration de 100 μg / ml. Les fractions restantes, GradEtOHa, GradI50a et GradII100a ont montré une activité significativement plus faible que PMII.
L’activité de l’IL-6 a été déterminée pour les fractions GradEtOH, GradI50, GradI100 et GradII100. Une activité pro-inflammatoire a été observée pour tous les extraits, mais aucun des échantillons n’a montré de propriétés anti-inflammatoires. Faute de temps, seuls 2 donneurs sur 8 ont été analysés et aucune conclusion définitive ne peut donc être tirée.

2011

Gayathri V. Patil, Sujata K. Dass and Ramesh Chandra
Artemisia afra and Modern Diseases
Journal of Pharmacogenomics & Pharmacoproteomics 2011, 2:3

Artemisia afra and Modern Diseases

Abstract :

Herb Artemisia afra has recently attracted worldwide attention of researchers for its possible use in the modern diseases like diabetes, cardiovascular diseases, cancer, respiratory diseases etc. This review is exhaustive and systematic organization of the available literature on Artemisia afra (A. afra) from January 1922 to July 2011. The literature survey presents the number of publications with respect to time. Patents are briefly described ; the traditional uses are classified and summarized. Some emphasis is given to the data and projections of modern diseases and the ongoing research in this area in the context of title of this review. The pharmacognostic aspects, chemical constituents and factors affecting it, the activity, analysis & quality control, pharmaceutical dosage form etc. is dealt in this review.

Keywords : Artemisia afra ; Patents ; Traditional uses ; Chemical constituents ; Activity ; Toxicity ; Dosage form

***

Kundan Singh Bora & Anupam Sharma
The Genus Artemisia : A Comprehensive Review
Pharmaceutical Biology, 2011, Volume 49, Issue 1, Pages 101-109

The Genus Artemisia : A Comprehensive Review

Abstract

Context : Medicinal plants are nature′s gift to human beings to make disease free healthy life, and play a vital role to preserve our health. They are believed to be much safer and proven elixir in the treatment of various ailments. The genus Artemisia (Astraceae) consists of about 500 species, occurring throughout the world. The present review comprises the ethnopharmacological, phytochemical and therapeutic potential of various species of Artemisia.

Objective : The aim of this this review is to bring together most of the available scientific research conducted on the genus Artemisia, which is currently scattered across various publications. Through this review the authors hope to attract the attention of natural product researchers throughout the world to focus on the unexplored potential of Artemisia species.

Methods : This review has been compiled using references from major databases such as Chemical Abstracts, Medicinal and Aromatic Plants Abstracts, ScienceDirect, SciFinder, PubMed, King′s American Dispensatory, Henriette′s Herbal Homepage, Dr. Duke′s Phytochemical and Ethnobotanical Databases.

Results : An exhaustive survey of literature revealed that the different species of Artemisia have a vast range of biological activities including antimalarial, cytotoxic, antihepatotoxic, antibacterial, antifungal and antioxidant activity. Some very important drug leads have been discovered from this genus, notably artemisinin, the well known antimalarial drug isolated from the Chinese herb Artemisia annua. Terpenoids, flavonoids, coumarins, caffeoylquinic acids, sterols and acetylenes constitute major classes of phytoconstituents of the genus.

Conclusion : Various species of Artemisia seems to hold great potential for in-depth investigation for various biological activities, especially their effects on the central nervous and cardiovascular systems.

Keywords: : Antimalarial, antimicrobial, Artemisia, cytotoxic, flavonoids, terpenoids.

2012

Andrea Lubbe, Isabell Seibert, Thomas Klimkait, Frank van der Kooy
Ethnopharmacology in overdrive : The remarkable anti-HIV activity of Artemisia annua (and Artemisia afra)
Journal of Ethnopharmacology, 2012 volume 141, issue 3

Ethnopharmacology in overdrive : The remarkable anti-HIV activity of Artemisia annua

Abstract :

Ethnopharmacological relevance : Artemisia annua contains the well-known antimalarial compound artemisinin, which forms the backbone of the global malaria treatment regime. In African countries a tea infusion prepared from Artemisia annua has been used for the treatment of malaria only for the past 10–20 years. Several informal claims in Africa exist that the Artemisia annua tea infusions are also able to inhibit HIV. Since HIV is a relatively newly emerged disease, the claims, if substantiated, could provide a very good example of “ethnopharmacology in overdrive”. The objective of this study was to provide quantitative scientific evidence that the Artemisia annua tea infusion exhibits anti-HIV activity through in vitro studies. A second objective was to determine if artemisinin plays a direct or indirect (synergistic) role in any observed activity. This was done by the inclusion of a chemically closely related species, Artemisia afra, known not to contain any artemisinin in our studies.

Materials and Methods : Validated cellular systems were used to test Artemisia annua tea samples for anti-HIV activity. Two independent tests with different formats (an infection format and a co-cultivation format) were used. Samples were also tested for cellular toxicity against the human cells used in the assays.
Results : The Artemisia annua tea infusion was found to be highly active with IC 50 values as low as 2.0 ?g/mL. Moreover we found that artemisinin was inactive at 25 ?g/mL and that a chemically related species Artemisia afra (not containing artemisinin) showed a similar level of activity. This indicates that the role of artemisinin, directly or indirectly (synergism), in the observed activity is rather limited. Additionally, no cellular toxicity was seen for the tea infusion at the highest concentrations tested.

Conclusion : This study provides the first in vitro evidence of anti-HIV activity of the Artemisia annua tea infusion. We also report for the first time on the anti-HIV activity of Artemisia afra although this was not an objective of this study. These results open the way to identify new active pharmaceutical ingredients in Artemisia annua and thereby potentially reduce the cost for the production of the important antimalarial compound artemisinin.

Keywords : Artemisia afra, Artemisia annua, Artemisinin, HIV, Malaria Tea infusion

***

Amidou Samie and Tshifhiwa Nefefe
Antifungal activities of essential oils from Southern African medicinal plants against five Fusarium species
Journal of Medicinal Plants Research, January, 2012, Vol. 6(3), pp. 465-478

Antifungal activities of essential oils from Southern African medicinal plants against five Fusarium species

Abstract :

In the present study, essential oils from 9 plants traditionally used to treat infectious diseases were tested against five Fusarium spp. using the agar diffusion method. The minimum inhibitory concentrations (MIC) of the oils were determined by the microdilution technique. The killing kinetics of the oils was further evaluated against the fungal organisms. Antifungal activity was exhibited by essential oils from Conyza scabrida, Eriocephallus panculatus, Artemesia afra, Pelargonium graveolons and Mentha peripeta with 100% growth inhibition against all the five Fusarium spp with the zone of inhibition ranging from 10 to 18 mm. The essential oils of C. scabrida and M. piperita were fungicidal to four of the five fungal species tested with minimum fungicidal concentration (MFC) values ranging from 0.95 to 7.50 mg/ml. All the essential oils tested were able to kill the cells at different rates varying from 48 to 100% after 2 days of experimentation. The results of the present study indicate that essential oils tested are promising sources of natural products with which could be used for the control of Fusarium infections. These results will guide the selection of some plant species for further pharmacological and phytochemical analysis. These results also support the traditional use of these essential oils.

Key words : Fusarium spp, anti-fungal activity, essential oils, fungi, Southern Africa, medicinal plants

***

María José Abad, Luis Miguel Bedoya, Luis Apaza, and Paulina Bermejo
The Artemisia L. Genus : A Review of Bioactive Essential Oils
Molecules. 2012 Mar ; 17(3) : 2542–2566.

The Artemisia L. Genus : A Review of Bioactive Essential Oils

Abstract :

Numerous members of the Anthemideae tribe are important as cut flowers and ornamental crops, as well as being medicinal and aromatic plants, many of which produce essential oils used in folk and modern medicine and in the cosmetics and pharmaceutical industry. Essential oils generally have a broad spectrum of bioactivity, owing to the presence of several active ingredients that work through various modes of action. Due to their mode of extraction, mostly by distillation from aromatic plants, they contain a variety of volatile molecules such as terpenes, phenol-derived aromatic and aliphatic components. The large genus Artemisia L., from the tribe Anthemideae, comprises important medicinal plants which are currently the subject of phytochemical attention due to their biological and chemical diversity. Artemisia species, widespread throughout the world, are one of the most popular plants in Chinese traditional preparations and are frequently used for the treatment of diseases such as malaria, hepatitis, cancer, inflammation and infections by fungi, bacteria and viruses. Extensive studies of the chemical components of Artemisia have led to the identification of many compounds as well as essentials oils. This review summarizes some of the main reports on the chemistry and anti-infective activities of Artemisia. Li. essential oils from the data in the recent literature (2000–2011).

Keywords : Artemisia L., essential oil, isoprenic structure, anti-infective

***

R. Hewer, F.H. Kriel, and J. Coates
Random and Rational Approaches to HIV Drug Discovery in Africa
in Kelly Chibale, Mike Davies-Coleman, Collen Masimirembwa, Editors, Drug Discovery in Africa, Impacts of Genomics, Natural Products, Traditional Medicines, Insights into Medicinal Chemistry, and Technology Platforms in Pursuit of New Drugs

Full text submitted to request

Abstract

The development of therapeutic agents to inhibit human immunodeficiency virus (HIV) replication began soon after the isolation and identification of the virus as the causative agent of the acquired immune deficiency syndrome (AIDS). Within a short period of time thereafter, azidothymidine (AZT) was found to inhibit viral replication and became the first FDA-approved drug for the treatment of HIV/AIDS in 1987. Since then, continual and substantial progress has been made. To date, 35 drugs have been clinically approved, and with treatment, HIV infection has been transformed from a life-threatening disease with a short survival rate into a chronic manageable condition. Furthermore, several drugs are currently under investigation in various stages of clinical and preclinical development. Despite this remarkable success, there is continued global effort directed towards the design, discovery and development of novel inhibitors that may improve treatment strategies and overcome new challenges that have arisen. This chapter focuses on the discovery phase of the HIV drug discovery and development pipeline and describes the contribution and progress made by African scientists and research laboratories. Review of the period 1990 to present day reveals considerable African research describing anti-HIV inhibitors, derived from natural sources or through synthetic means, and identified through both rational and random drug discovery approaches. Several challenges facing HIV researchers on the continent disproportionately affected by HIV/AIDS are also described.

Keywords : Human Immunodeficiency Virus Acquire Immune Deficiency Syndrome Rational Drug Design Human Immunodeficiency Virus Protease Inhibitor Drug Development Pipeline

2013

Frank Van der Kooy
Reverse Pharmacology and Drug Discovery : Artemisia annua and Its Anti-HIV Activity
In : Aftab T., Ferreira J., Khan M., Naeem M. (eds) Artemisia annua - Pharmacology and Biotechnology. Springer, Berlin, Heidelberg, 27 November 2013, pp 249-267

Reverse Pharmacology and Drug Discovery : Artemisia annua and Its Anti-HIV Activity

Abstract

There are various ways in which new drugs can be developed. One approach is in silico drug design based on our existing knowledge of the biology of a specific disease and the specific target site binding chemistry. Based on this knowledge, a range of molecules will be designed and synthesised after which they will be tested in in vitro bioassays for activity and toxicity. The best candidates, called lead compounds, will then be “fine-tuned” by chemical derivatisation in order to improve their activity and/or to reduce their toxicity. Lead compounds are then tested in various animal models before entering clinical trials in people. Another approach is to screen a large number of biological samples (plants, bacteria and fungi) for activity against a specific disease. Any active extract, consisting of many compounds, will be fractionated by chromatographic techniques, and each fraction will be tested for in vitro activity. Active fractions will again be fractionated until the active compound is identified. This process, also called bioguided fractionation, can go through a number of fractionation cycles before the active compound is identified. The active compound will be chemically derivatised in order to improve its properties before in vivo animal studies will be conducted. Based on these test results, the most promising lead compounds will then be tested in clinical trials in people. There are however a number of shortcomings with both approaches. It is expensive, time consuming, makes use of in vitro bioassays and it suffers from a very low success rate. Due to these shortcomings, it is currently estimated that the development of one new drug costs around $1–1.5 billion, simply because so many lead compounds fail during clinical trials. Keeping these high costs in mind, one would think that all registered drugs are effective and importantly non-toxic. Unfortunately, this is not the case, as there are a number of drugs currently on the market that are causing severe side effects and whose efficacy should be questioned. This holds true particularly for cancer chemotherapeutics. It was estimated that cancer chemotherapy improves the average 5-year survival rate of patients (for all cancer types) by only 2 % (Morgan et al. 2004). Another relatively unknown fact is that each year, 200,000 people die in the EU due to adverse drug reactions (all types of drugs), highlighting the severe shortcomings of the drug development and drug licensing pipelines (Archibald and Coleman 2012). To put this into perspective, there are a large number of drugs that work perfectly well and are safe to use, but we have to concede that our approach to drug discovery and our overall approach to health care suffers from some major problems.

Keywords :
Medicinal Plant Chlorogenic Acid Bovine Viral Diarrhoea Virus Artemisinin Derivative Vitro Bioassay

***

Peter Masoko and Kulani Mashudu Nxumalo
Validation of Antimycobacterial Plants Used by Traditional Healers in Three Districts of the Limpopo Province (South Africa)
Complementary and Alternative Medicine, volume 2013 (2013)

Validation of Antimycobacterial Plants Used by Traditional Healers

Abstract

The aim of the study was to scientifically evaluate the antimycobacterial activity of selected indigenous medicinal plants from the Limpopo Province used for the treatment of humans with symptoms of Mycobacterium tuberculosis. The leaves of five plant species (Apodytes dimidiata, Artemisia, Combretum hereroense, Lippia javanica, and Zanthoxylum capense) were collected from the Lowveld National Botanical Garden in Nelspruit, South Africa. The dried leaves were powdered and extracted using hexane, dichloromethane, acetone, and methanol. Antimycobacterial activity was evaluated using microdilution assay and bioautography and ρ-iodonitrotetrazolium violet (INT) as indicator. Antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH). Phytochemical content of extracts was further evaluated. The acetone extracts of L. javanica displayed antioxidant activity on BEA chromatogram. T Acetone extracts of A. afra had MIC value of 0.39 mg/mL against Mycobacterium smegmatis ATCC 1441. Acetone extracts of C. hereroense and L. javanica had MIC value of 0.47 mg/mL. Four bands that inhibited the growth of M. smegmatis were observed at values of 0.12, 0.63, and 0.87 on BEA and 0.73 on EMW. The plant species A. dimidiata, A. afra, C. hereroense, and L. javanica in this study demonstrated their potential as sources of anti-TB drug leads.

***

Megan C. Pruissen
Evaluation of plant extracts : Artemisia afra and Annona muricata for inhibitory activities against Mycobacterium tuberculosis and Human Immunodeficiency virus
Dissertation submitted in fulfillment of the requirements for the degree of Magister Scientiae in the Faculty of Science at the Nelson Mandela Metropolitan University, January 2013.

Evaluation of plant extracts : Artemisia afra and Annona muricata for inhibitory activities against Mycobacterium tuberculosis and Human Immunodeficiency virus

Abstract

Mycobacterium tuberculosis and Human Immuno-Deficiency Virus (HIV) have a high prevalence in South Africa. The development and spread of drug resistant tuberculosis is a serious problem which is exacerbated by tuberculosis (TB) co-infection in HIV patients. Traditional medicinal plants like Annona muricata and Artemisia afra are used for respiratory ailments and antiviral therapies respectively. The aim of this study was to evaluate Annona muricata (ethanolic extract) and Artemisia afra (ethanolic and aqueous extracts) for inhibitory activities against M. tuberculosis and HIV. In vitro bioassays for anti-TB activity included : microplate alamar blue assay (MABA), flow cytometry and ρ-iodonitrotetrazolium chloride assays while anti-HIV activity was determined using an HIV-1 reverse transcriptase colorimetric ELISA kit and an HIV-1 integrase colorimetric immunoassay. Cytotoxicity of plant extracts were assessed by the MTT assay on Chang Liver and HepG2 cells. Potential synergistic effects were determined using the basis of Combination Index. Potential interactions of plant extracts with drug metabolic pathways were evaluated with the Glutathione-S-Transferase assay kit as well as the CYP3A4 assay kit. A. muricata ethanolic extract exhibited anti-TB activity with MIC 125 μg/mL. MABA was shown to be the most sensitive and effective method for the detection of anti-TB activity. Artemisia afra aqueous extract showed HIV-1 reverse transcriptase inhibition exhibiting ˃85% inhibition at 1 mg/mL while the ethanolic extracts of A. afra and A. muricata showed inhibition of HIV-1 integrase activity at ˃86.8% and ˃88.54% respectively at concentrations >0.5 - 4 mg/mL. The aqueous extract of A. afra displayed inhibition of HIV-1 integrase ˃52.16% at 0.5 mg/mL increasing to 72.89% at 4 mg/ml of the extract. A. muricata was cytotoxic at an IC50 of 30 μg/mL and 77 μg/mL on Chang Liver and HepG2 cells respectively, whilst A. afra aqueous and ethanol extracts were not cytotoxic to both cell lines. The ethanolic extract of A. muricata showed both antagonistic and synergistic properties at various IC values, when used in conjunction with rifampicin. A. afra ethanolic extract interrupted GST activity while aqueous extracts of A. afra and A. muricata had a slight effect. All extracts interrupted CYP3A4 activity, however the ethanolic extracts of A. muricata and A. afra showed greater inhibition than the aqueous extract of A. afra. These extracts should be investigated further as they could be an important source of compounds for treatment of M. tuberculosis and HIV respectively.

***

Nhlanhla Wiseman Nsele
Assessment of the antibacterial activity of Artemisia afra, Erythrina lysistemon and Psidium guajava
Dissertation submitted in fulfilment for the requirements of the degree of Master of Technology in Biomedical Technology in the Faculty of Health Sciences at the Durban University of Technology

Assessment of the antibacterial activity of Artemisia afra, Erythrina lysistemon and Psidium guajava

Abstract

Introduction : Medicinal plants have been used for centuries as remedies for human diseases because they contain components of therapeutic value. Recently, the acceptance of traditional medicine as an alternative form of health care and the development of microbial resistance to the available antibiotics have led scientists to investigate the antimicrobial activity of medicinal plants Aim The aim of this study was to investigate the antimicrobial activity of extracts obtained from medicinal plants used in traditional medicine. A comparative study was carried out on the antimicrobial properties of extracts obtained by two different methods in order to choose that which extracts the most effective antimicrobial compounds.

Methodology : The plants used in this study Artemisia afra, Erythrina lysistemon and Psidium guajava were harvested from the Silverglen Nature Reserve (Chatsworth) early in the morning (8 a.m.). The leaves of A. afra and P. guajava extracts and the bark of E. Lysistemon were used to prepare the extracts. All plant extracts were prepared according to modified method of the German Homeopathic Pharmacopoea. Two solvents, water and 60 percent ethanol were used to extract the antibacterial compounds from plant material. The extracts were then assessed for their antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The effect of the plant extracts on these bacteria was determined by the disk diffusion test, which was used as the screening test. Positive results were further subjected to the minimum inhibitory concentration and minimum bactericidal concentration assays. Tubes that showed no turbidity were then sub-cultured onto non-selective plates. Bacterial iii sensitivity testing was carried out in accordance with modified Kirby-Bauer Antimicrobial Sensitivity Test. An attempt was made to identify some antibacterial compounds using Thin Layer Chromatography and High Pressure Liquid Chromatography.

Results : None of the gram negative organisms were inhibited by Artemisia afra, Erythrina cafra and Psidium guajava. Only the ethanol extracts of all three plants were able to inhibit Staphylococcus aureus but not Escherichia coli and Pseudomonas auruginosa. None of the test organisms were inhibited by the aqueous extracts of all three plants used in this study. In the screening test, the zones of inhibition for ethanol extracts against Staphylococcus aureus ranged from 3mm – 7mm. The minimum inhibitory concentration ranged from 16.67 percent – 83.3 percent inhibition depending on the dilution of the extract. Quercetin and Catechin were identified as some of the antibacterial compounds present in the leaves of Psidium guajava. These two compounds were not identified on Erythrina lysistemon and Artemisia afra.

Conclusion : The results obtained in this study have proven that Artemisia afra, Erythrina cafra and Psidium guajava ethanol extracts contain antibacterial substances. The ethanol extracts of all plants in this study inhibited the growth of Staphylococcus aureus but had no effect on the gram negative bacteria. Aqueous plant did not inhibit the growth of any bacteria in this study. This study has also shown that antibacterial effect of these extracts may be considerably enhanced in traditional treatment if traditional healers can include ethanol as one of the extraction solvents. The results obtained in this study might be considered sufficient for further studies aimed at isolating and identifying the active compounds and evaluating possible synergism of antimicrobial iv activity among these extracts. Investigations on toxicity of these extracts should also be carried out.

***

M. Fawzi Mahomoodally, Ameenah Gurib-Fakim
Harnessing Traditional Knowledge to Treat Existing and Emerging Infectious Diseases in Africa
in Fighting Multidrug Resistance with Herbal Extracts, Essential Oils and Their Components, Editors : Mahendra Rai Kateryna Kon
2013, Pages 223-235 (Chapter 15)

Harnessing Traditional Knowledge to Treat Existing and Emerging Infectious Diseases in Africa

Abstract

Infectious diseases are responsible for one in every two deaths in many developing countries, but people in sub-Saharan Africa are particularly vulnerable, as poverty is rampant and access to health care is limited. Additionally, the unregulated use of antibiotics in some parts of Africa has led to the emergence of resistance in pathogens. Indeed, one of the biggest pandemics is malaria, which kills millions annually. Currently, artemisinin (effective against chloroquine-resistant Plasmodium) is the only weapon available to fight this pandemic, yet the World Health Organization has reported with concern that some countries in Southeast Asia are beginning to witness resistance to artemisinin. As a consequence, increasing attention is being drawn to botanicals, as they have the potential to provide alternative and complementary therapies, as well as potential leads to address emerging infections and resistance. This chapter will review some medicinal plants from the African Herbal Pharmacopoeia that show promise for containing existing and emerging infectious diseases.

Keywords : traditional knowledge, herbal remedies, Sub-Saharan Africa, African Herbal Pharmacopoeia, emerging infectious diseases

2014

Muleya E, Ahmed AS, Sipamla AM, Mtunzi FM and Mutatu W
Evaluation of Anti-Microbial, Anti-Inflammatory and Anti-Oxidative Properties of Artemisia afra, Gunnera perpensa and Eucomis autumnalis
Nutrition and Food Sciences, 2014, volume 4, issue 6

Evaluation of Anti-Microbial, Anti-Inflammatory and Anti-Oxidative Properties of Artemisia afra, Gunnera perpensa and Eucomis autumnalis

Abstract

Antimicrobial, anti-inflammatory and free radical scavenging activities of crude root extract fractions from Artemisia afra, Gunnera perpensa and Eucomis autumnalis were determined. Minimum inhibitory concentration was determined by using micro dilution method. In order to assess antioxidant scavenging capacity of plant extracts and fractions, 2, 2-di (4-tert-octylphenyl)-1-picrylhydrazyl and 2, 2´-azinobis (3-ethylbenzothiazoline)-6-sulfonic was used as substrate. Anti-inflammatory activity of the plant extracts against 15-soybean lipoxygenase enzyme was evaluated by measuring change in absorbance at 234 nm using linoleic acid as substrate. The highest activity was obtained from methanol fraction of Gunnera perpensa with EC50 value of 1.069 µg/ml against 2,2-di (4-tert-octylphenyl)-1-picrylhydrazyl. Eucomis autumnalis crude and acetone fraction displayed DPPH free radical scavenging activity of EC50 of 2.891 µg/ ml and 2.41 µg/ ml respectively. Artemisia afra crude fraction and fractions of acetone and methanol displayed activity (EC50 for DPPH radical, 2.113 µg/ ml with crude 4.393 µg/ ml with acetone fraction, 4.715 µg/ ml, with methanol fraction and with ABTS•+ radical cation, 6.447 µg/ ml and 6.208 µg/ ml from crude and methanol fraction respectively). The antioxidant properties of the extracts increased with the polarity of the fractions. Gunnera perpensa crude extract and fractions displayed antimicrobial properties with the methanol fraction being the most active with an EC50 of 80 µg/ ml, against Pseudomonas aeruginosa and EC50 of 160 µg/ml against Candida albicans. Artemisia afra acetone and methanol fractions displayed inhibitory activities of 20 µg/ml against Escherichia coli and good-moderate activity ranging 160-320 µg/ml for the crude extract. Eucomis autumnalis had activities ranging 160-320 µg/ml by the crude extract and fractions against the organisms tested except for crude extract activity against Escherichia coli of 630 µg/ml. The activities validate claims by the traditional healers use for cure offering possible alternative as dietary supplements to the management of inflammation related conditions.

Keywords : Minimum inhibitory concentrations (MIC) ; Reactive oxygen species (ROS) ; Reactive nitrogen species (RNS).

***

Liang Tzung Lin, Wen Chan Hsu, Chun Ching Lin
Antiviral Natural Products and Herbal Medicines
Journal of Traditional and Complementary Medicine, 2014, Vo1. 4, No. 1, pp. 24-35

Antiviral Natural Products and Herbal Medicines

Abstract :

Viral infections play an important role in human diseases, and recent outbreaks in the advent of globalization and ease of travel have underscored their prevention as a critical issue in safeguarding public health. Despite the progress made in immunization and drug development, many viruses lack preventive vaccines and efficient antiviral therapies, which are often beset by the generation of viral escape mutants. Thus, identifying novel antiviral drugs is of critical importance and natural products are an excellent source for such discoveries. In this mini‑review, we summarize the antiviral effects reported for several natural products and herbal medicines

Key words : Antiviral, Drug development, Herbal medicines, Natural products

***

Lawal, I. O. ; Grierson, D. S. ; Afolayan, A. J.
Phytotherapeutic Information on Plants Used for the Treatment of Tuberculosis in Eastern Cape Province, South Africa
Evidence-based Complementary and Alternative Medicine, April 2014, (2014), 735423

Phytotherapeutic Information on Plants Used for the Treatment of Tuberculosis in Eastern Cape Province, South Africa

Abstract :

The current rate of deforestation in Africa constitutes a serious danger to the future of medicinal plants on this continent. Conservation of these medicinal plants in the field and the scientific documentation of our knowledge about them are therefore crucial. An ethnobotanical survey of plants used for the treatment of tuberculosis (TB) was carried out in selected areas of the Eastern Cape, South Africa. These areas were Hala, Ncera, Sheshegu, and Gquamashe, all within the NkonkobeMunicipality. One hundred informants were interviewed.The survey included the identification of scientific and vernacular names of the plants used for treatment of TB as well as the methods of preparation and administration, the part used, dosage, and duration of treatment. The survey revealed 30 plants belonging to 21 families which are commonly used by traditional healers for the treatment of TB and associated diseases. Of these plants Clausena anisata, Haemanthus albiflos, and Artemisia afra were the most cited. The leaves were the most common part used in the medicinal preparations. Our findings are discussed in relation to the importance of the documentation of medicinal plants.

***

Z. Hübsch, R.L. Van Zyl, I.E. Cock, S.F.Van Vuuren
Interactive antimicrobial and toxicity profiles of conventional antimicrobials with Southern African medicinal plants
South African Journal of Botany, Volume 93, July 2014, Pages 185-197

Interactive antimicrobial and toxicity profiles of conventional antimicrobials with Southern African medicinal plants

Abstract :

Medicinal plant use plays an important role in the healthcare of many South Africans. Furthermore, in orthodox medicine, conventional antimicrobial agents are amongst the most commonly prescribed groups of drugs. Therefore, due to the prevalence of use of these two forms of healthcare, there is a high probability for their concurrent use. Thus, the aim of this study was to evaluate the interactive antimicrobial and toxicity profiles of six Southern African medicinal plants (Agathosma betulina, Aloe ferox, Artemisia afra, Lippia javanica, Pelargonium sidoides and Sutherlandia frutescens) when combined with seven conventional antimicrobials (ciprofloxacin, erythromycin, gentamicin, penicillin G, tetracycline, amphotericin B and nystatin). Antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) assay against a range of pathogens and interactions were further classified using the sum of the fractional inhibitory concentration (∑FIC). Notable synergistic or antagonistic interactions were studied at various ratios (isobolograms). The toxicity of the individual samples, as well as the notable combinations, was assessed using the brine-shrimp lethality assay (BSLA) and the 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on the HEK-293 human cell line. Of the 420 antimicrobial:plant combinations studied, 14.29% showed synergistic interactions, 7.56% antagonistic, 35.71% additive and 42.44% indifferent interactions. Some notable synergistic interactions (ciprofloxacin with A. betulina and S. frutescens against Escherichia coli) and antagonistic interactions (ciprofloxacin with A. afra organic extract against Escherichia coli) were identified. None of the notable combinations were found to show toxicity in the BSLA or MTT assay. In conclusion, the majority of combinations were found to have no notable interaction, alleviating some concern related to the concurrent use of these two forms of healthcare.

Keywords : Conventional antimicrobials, Interaction ; Medicinal plants, Southern Africa, Toxicity

2015

Mphuthi, Ditaba David
Anti-viral properties of wildeals (Artemisia afra) and wynruit (Ruta graveolens) as combination therapy and its effects on the renal system
Thesis submitted for the fulfillment of the requirements for the degree of Doctor of Philosophy North-West University (Mafikeng Campus)

Anti-viral properties of wildeals (Artemisia afra) and wynruit (Ruta graveolens) as combination therapy and its effects on the renal system

Abstract

Globally, approximately 80% of the population is using indigenous medicines. This is because indigenous medicines are less expensive and since the indigenous healers are residing within their communities. The indigenous people trust medicinal plants more than Western medicines, because they have been using them since time immemorial. Wildeals (Artemisia afra) and wynruit (Ruta graveolens) are other medicinal plants that have been used by some indigenous people in South Africa to treat several conditions. These have mostly been used as mono therapies, but in the Northern Cape Province, Griqualand-West, South Africa, they are being used as combination therapies also. A combination of wildeals and wynruit is a commonly used medicinal decoction in the Northern Cape Province in South Africa. The aims of this research were to confirm scientific knowledge regarding the anti-viral properties of such wildeals and wynruit decoctions, prepared either as single, or combination therapies, as well as to investigate their effects on the renal system. To achieve these, the anti-viral properties in vitro and the effects on the renal system in vivo were investigated during this study. The decoctions were tested in vitro against the influenza virus (common cold), and in vivo for any possible undesirable effects on the renal system, using Sprague-Dawley rats. This research project had followed a mixed method approach, with a multiphase design. Research phase 1 comprised of the realisation of the qualitative approach, phase two involved a systematic review, while phase 3 consisted of the in vitro testing and phase 4 of the in vivo experimental procedures. Population and sampling were in accordance with the objectives of each phase. Data was collected and analysed in accordance with the objectives of each phase, since a multiple approach to data collection and analysis was used during this research project. This study comprised of a baseline type of research, where hybrid science was used to generate baseline knowledge. The decoctions being investigated during this research had been prepared authentically by the rural Griqua community, under pragmatic conditions, and subjected to testing in a western science laboratory. The findings revealed that the combination therapy and the one medicinal plant (wildeals) had proven effective against the influenza virus. In vitro medicinal plant (wynruit) had demonstrated some resistance, which may have resulted from possible contamination during uncontrolled preparation by the community member. No undesirable effects on the kidneys and livers of rats were identified. It was concluded that the tested decoctions, as prepared by the Griqua community from wildeals and wynruit for this study, had appeared safe and effective for human consumption. This outcome could significantly impact on future health care in South Africa, if co-existence between Indigenous and Western health systems is promoted and achieved.

***

Tjokosela Tikiso
Comparison of flavonoid profile and respiratory smooth muscle relaxant effects of Artemisia afra versus Leonotis leonurus
Thesis submitted in fulfilment of the requirements for the degree of Magister Scientiae (Pharmaceutical Sciences) in the Discipline of Pharmacology at the University of the Western Cape, Bellville, South Africa. September 2015

Comparison of flavonoid profile and respiratory smooth muscle relaxant effects of Artemisia afra versus Leonotis leonurus

Summary

Leonotis leonurus (L. leonurus) and Artemisia afra (A. afra) are two of the most commonly used medicinal plants in South Africa traditionally advocated for use in asthma. However, proper scientific studies to validate these claimed uses are lacking and little is known about the mechanisms for this effect. These plants contain flavonoids, which are reported to have smooth muscle relaxant activity and may be responsible for the activity of these two plants. The objectives of this study were to : (1) determine and compare the flavonoid profiles and levels in A. afra and L. leonurus, (2) compare the respiratory smooth muscle relaxant effects of freeze-dried aqueous extracts of A. afra and L. leonurus and (3) investigate whether K+ - channel activation (i.e. KATP channel) is one possible mechanism of action that can explain the effect obtained in traditional use of these two plants. It was hypothesized that : (1) the flavonoid levels and profile of A. afra would be greater than the flavonoid levels and profile of L. leonurus, (2) A. afra would have a more potent respiratory muscle relaxant effect than L. leonurus and (3) A. afra and L. leonurus will inhibit K+ - induced contractions in a superior manner than carbachol and histamine - induced contractions. To realize these objectives, freeze-dried aqueous extracts (FDAE) of the dried leaves of the two plants were prepared. A validated HPLC assay was developed and used to identify and determine the levels of luteolin in the plant preparations. Solutions of the plant extracts were studied in the isolated guinea-pig trachea tissue preparation in the presence of carbachol, histamine and KCL. The possible mechanism of action of the two plants was determined by cumulative log dose-response curves (LDRC) for carbachol, histamine and KCL in the absence and presence of 1, 30 and 100 mg/ml solutions of the plant extracts. The flavonoid profile of un-hydrolyzed and hydrolyzed L. leonurus was greater than that of un-hydrolyzed and hydrolyzed A. afra. The levels of free and total luteolin in A. afra FDAE (8.977 ± 0.73 µg/ml and 16.394 ± 0.884 µg/ml, respectively) were significantly (p < 0.001) higher than that in L. leonurus FDAE (0.929 ± 0.066 µg/ml and 3.093 ± 0.531 µg/ml, respectively). L. leonurus and A. afra relaxed tracheal smooth muscles contracted with iv histamine, KCL and carbachol in a dose dependent manner. The degree of relaxant activity of L. leonurus versus the three inducers of contraction (agonists) could be classified as KCL > carbachol > histamine, with EC50 values of 9.87, 29.34 and 94.76 mg/ml, respectively. The A. afra tracheal smooth muscle relaxant activity was categorized as carbachol > histamine > KCL, with EC50 values of 13.93, 15.47 and 19.88 mg/ml, respectively. Overall, A. afra which contained the higher levels of luteolin, was more potent at relaxing the guinea pig tracheal smooth muscle than L. leonurus. Collectively, the results confirm that aqueous solutions of A. afra and L. leonurus as used in local traditional practice have potent but different degrees of bronchodilator activities that could be useful in the treatment of asthma, and that these actions may be related to each plant‟s luteolin (or flavonoid) levels. Moreover it is very unlikely that KATP channels are primarily responsible for the actions of A. afra and L. leonurus, but rather that more than one mechanism of action is involved in the tracheal smooth muscle relaxant effects of these two plants.

Key words : Artemisia afra Leonotis leonurus Freeze dried aqueous extract Trachea smooth muscle relaxant Isolated guinea-pig trachea Flavonoids Luteolin HPLC

***

Bianca Ivanescu, Anca Miron, and Andreia Corciova
Sesquiterpene Lactones from Artemisia Genus : Biological Activities and Methods of Analysis
Journal of Analytical Methods in Chemistry, 2015 ; 2015 : 247685.

Sesquiterpene Lactones from Artemisia Genus : Biological Activities and Methods of Analysis

Abstract :

Sesquiterpene lactones are a large group of natural compounds, found primarily in plants of Asteraceae family, with over 5000 structures reported to date. Within this family, genus Artemisia is very well represented, having approximately 500 species characterized by the presence of eudesmanolides and guaianolides, especially highly oxygenated ones, and rarely of germacranolides. Sesquiterpene lactones exhibit a wide range of biological activities, such as antitumor, anti-inflammatory, analgesic, antiulcer, antibacterial, antifungal, antiviral, antiparasitic, and insect deterrent. Many of the biological activities are attributed to the 𝛼-methylene-𝛾-lactone group in their molecule which reacts through a Michael-addition with free sulfhydryl or amino groups in proteins and alkylates them. Due to the fact that most sesquiterpene lactones are thermolabile, less volatile compounds, they present no specific chromophores in the molecule and are sensitive to acidic and basic mediums, and their identification and quantification represent a difficult task for the analyst. Another problematic aspect is represented by the complexity of vegetal samples, which may contain compounds that can interfere with the analysis. Therefore, this paper proposes an overview of the methods used for the identification and quantification of sesquiterpene lactones found in Artemisia genus, as well as the optimal conditions for their extraction and separation.

2016

Pierre Lutgen
Tannins in Artemisia : hidden treasure for prophylaxis
Text published on the web site Malaria world, October 9, 2016

Tannins in Artemisia : hidden treasure for prophylaxis

No abstract

Excerpt :

« In Artemisia afra very high concentrations were found : 1 990 mg/100g.3 [...] Artemisia annua kills Paramecium tetraurelia. The effect of Artemisia afra is even stronger. A recent study reveals that the human gut bacteria Escherichia coli, normally considered a microbe of pathogenic potential within the host, may help us end off malaria infection. »

2017

Mujeeb Hoosen
The use of whole blood cell cultures as a model for assessing the effects of SeptilinTM on the immune system
Thesis submitted in partial fulfilment of the requirement for the degree of Magister Scientiae (MSc) at the University of the Western Cape, South Africa. August 2017

The use of whole blood cell cultures as a model for assessing the effects of SeptilinTM on the immune system

Abstract :

In the past three decades there has been a huge increase in the use of herbal medicine globally. The active principles of these herbal medicines are mostly unknown with supportive evidence for safety and efficacy very rare. SeptilinTM is a phytopharmaceutical formulation which is recommended for the treatment and management of various infections. It has been claimed to have immunomodulatory actions that potentiates the body’s immune response. The immunomodulatory activity of SeptilinTM has not been well investigated via appropriate in vitro models. Therefore this study was undertaken to investigate the in vitro effects of SeptilinTM on biomarkers of specific immune pathways by using WBC. Stimulated and unstimulated WBC were incubated with the product. Enzyme linked immunosorbent assays were used to screen for IL-6, IL-10, and IFNγ as biomarkers for inflammation, humoral immunity, and cell mediated immunity, respectively. Results show that the presence of SeptilinTM in LPS stimulated WBC has no effect on the release of IL-6 and IFNγ production but stimulated IL-10 production. SeptilinTM in unstimulated WBC has no effect on the release of IL-10 and IFNγ production but stimulatory effects on IL-6 production. This study also assessed the effects of Artemisia afra, Aspalathus linearis (rooibos), and SeptilinTM on inflammatory biomarkers namely, IL-6 and nitric oxide (NO) using RAW 264.7 cells, a murine macrophage cell line. The results of this study indicate that Artemisia afra has anti-inflammatory effects while Aspalathus linearis (rooibos) up regulated the immune system. The study also shows that SeptilinTM has no immunomodulatory effects on RAW 264.7 cells.

Key words : Artemisia afra, cell mediated immunity, cytokines, herbal medicinal products, human whole blood culture, humoral immunity, inflammation, RAW 264.7 macrophages, Aspalathus linearis (rooibos), SeptilinTM

***

Adil Hussain, Muhammad Q. Hayat, , Sumaira Sahreen, Qurrat ul Ain, and Syed A. I. Bokhari
Pharmacological Promises of Genus Artemisia (Asteraceae) : a Review
Proceedings of the Pakistan Academy of Sciences : Pakistan Academy of Sciences
B. Life and Environmental Sciences 54 (4) : 265–287 (2017)

Pharmacological Promises of Genus Artemisia (Asteraceae) : a Review

Abstract :

A huge amount of scientific literature is available about plant extracts and their compounds having great pharmacological importance. Although, plant-based medicines have been used since antiquity, but knowledge about their effectiveness on human health is still unclear. Artemisia genus belongs to the plant family Asteraceae. This genus comprises of about 500 species, which are well known for their medicinal properties. The aim of this review was to provide an insight about recent published scientific literature concerning pharmacological aspects of genus Artemisia. The compilation of literature has been done by using references from important databases such as Science Direct, Medicinal and Aromatic Plants Abstracts, PubMed, Chemical Abstracts, Kings American Dispensatory, SciFinder, Research gate, Google Scholar and Phytochemical and Ethnobotanical Databases. In this review, special emphases have been given to the reported chemical compounds and biological activities from different Artemisia species. This review emphasis on the plant species from genus Artemisia possessing significant phytochemicals holding
a broad range of biological actions like antimicrobial, antimalarial, anti-cancerous, antioxidant and anthelmintic activity. Certain crucial drugs have been unveiled from different species of Artemisia. One important constituent focused by researchers is artemisinin, which retains potential anti-malarial assets and is attained from Artemisia annua. Other groups of phytochemicals like flavonoids, steroids, glycosides, terpenoids, caffeoylquinic acids, acetylenes, coumarins and sterols are also found in this crucial genus. This genus also holds great possibilities for comprehensive scrutiny for other biological activities. The effects of constituents from various species of this genus on other deadly diseases may give better consequences.

Keywords : Asteraceae, genus Artemisia, phytochemicals, biological activities, bioactive compounds

***

Peter Masoko, Salmon A. Adebayo
Therapeutic uses of plant species for inflammation-related conditions in Limpopo province of South Africa : a mini-review and current perspectives
International Journal of Pharmacognosy and Phytotherapy Research
Vol. 2(1), pp. 027-041, February, 2017

{Therapeutic uses of plant species for inflammation-related conditions in Limpopo province of South Africa : a mini-review and current perspectives

Abstract

Impaired inflammatory response could result in undesirable effects as seen in chronic diseases such as tuberculosis (TB) and cancer. This study was based on an ethno-botanical survey of 6literature citations of medicinal plants used to treat inflammation-related conditions in Limpopo province of South Africa. Plant species belonging to the Fabaceae family are mostly used for these purposes, representing 16.1% of the recorded plants species. The root was the preferred plant part (50.9%) used for inflammation-related conditions, followed by the leaves (18.4%), stem bark (16.7%), whole plant (9.6%), the bulbs (3.5%) and the seed (0.9%) consecutively. The same plant species or a different part thereof is sometimes used to treat inflammation caused by different ailments. Traditional medicine continues to play a vital role in meeting the health care needs of people in under-resourced areas such as the Limpopo province. However, a curious finding in this review is the dearth of information on the traditional uses and exploitability of Harpagophytum procumbens. Extracts from H. procumbens are well known for their anti-inflammatory activities. Controlled harvesting of H. procumbens could potentially provide the much needed income for the people in the areas of the Limpopo province where this plant species is available.

2018

Richa Goel, Vijender Singh, Raj Kumari, Renu Kumari, Suchi Srivastava, Gopal Rao Mallavarapu, Divya Goel, And Sushil Kumar
Artemisia (Asteraceae) Essential Oils : Compositional Variation and Mechanisms of Its Origin, Biosynthesis of Constituents, Correspondence Between Biological Activities and Ethnomedicinal Usage and Repurposement Prospects
Proceedings of the Indian National Science Academy, 85 No. 4 December 2019 pp. 723-790

Artemisia (Asteraceae) Essential Oils : Compositional Variation and Mechanisms of Its Origin, Biosynthesis of Constituents, Correspondence Between Biological Activities and Ethnomedicinal Usage and Repurposement Prospects

Abstract

Many species of the genus Artemisia, a taxon in the angiosperm family Asteraceae composed of more than 500 species, are widely used in traditional medicine, on account of the safe multi-curative properties of its secondary metabolites biosynthesized in chloroplasts and cytoplasm of cells, largely in trichomes. The steam distilled Artemisia essential oils, into which the volatile organic metabolites get extracted, have been observed to demonstrate enormous intra- and interspecies variation. This review summarises for the Artemisia species (artemisias) the nature of compositional variation of the essential oil volatiles, biosynthetic processes of the major classes of the observed volatiles, and mechanisms responsible for the variation in the content of volatiles in essential oils. The inter-relationships between the biosyntheses of volatiles of essential oil and the antimalarial compound artemisinin are delineated. Further, the relationships between ethnomedicinal uses of various artemisias and biological activities detected in their essential oils are discussed with reference to the quality of essential oils. Artemisia essential oils offer highly significant repurposement prospects. Future directions of research on artemisias are also outlined.

Keywords : Biosynthetic Pathways ; Morpho-Chemi-Genetic Variation ; Marker Volatiles ; Essential Oil Volatiles ; Trichomes ; Artemisia Species Diversity

***

Bahare Salehi, Nanjangud V. Anil Kumar, Bilge ¸Sener, Mehdi Sharifi-Rad, Mehtap Kılıç, Gail B. Mahady, Sanja Vlaisavljevic, Marcello Iriti, Farzad Kobarfard, William N. Setzer Seyed Abdulmajid Ayatollahi, Athar Ata and Javad Sharifi-Rad
Medicinal plants used in the treatment of human immunodeficiency virus
International Journal of Molecular Sciences, 2018 May 14 ; 19 (5)

Medicinal plants used in the treatment of Human Immunodeficiency Virus

Abstract :

Since the beginning of the epidemic, human immunodeficiency virus (HIV) has infected around 70 million people worldwide, most of whom reside is sub-Saharan Africa. There have been very promising developments in the treatment of HIV with anti-retroviral drug cocktails. However, drug resistance to anti-HIV drugs is emerging, and many people infected with HIV have adverse reactions or do not have ready access to currently available HIV chemotherapies. Thus, there is a need to discover new anti-HIV agents to supplement our current arsenal of anti-HIV drugs and to provide therapeutic options for populations with limited resources or access to currently efficacious chemotherapies. Plant-derived natural products continue to serve as a reservoir for the discovery of new medicines, including anti-HIV agents. This review presents a survey of plants that have shown anti-HIV activity, both in vitro and in vivo.

Keywords : acquired immune deficiency syndrome, phytochemistry, pharmacognosy, antiviral, drug discovery

***

Paula Marie Braünlicha, Kari Tvete Inngjerdingen, Marit Inngjerdingen, Quinton Johnson, Berit Smestad Paulsena, Wilfred Mabusela
Polysaccharides from the South African medicinal plant Artemisia afra : Structure and activity studies
Fitoterapia, Volume 124, January 2018, Pages 182-187

Polysaccharides from the South African medicinal plant Artemisia afra : Structure and activity studies

Abstract

Artemisia afra (Jacq. Ex. Willd), is an indigenous plant in South Africa and other parts of the African continent, where it is used as traditional medicine mostly for respiratory conditions. The objective of this study was to investigate the structural features of the polysaccharides from the leaves of this plant, as well as the biological activities of the polysaccharide fractions against the complement assay. Leaves of Artemisia afra were extracted sequentially with organic solvents (dichloromethane and methanol), 50% aqueous ethanol, and water at 50 and 100 °C respectively. The polysaccharide extracts were fractionated by ion exchange chromatography and the resulting fractions were tested for biological activity against the complement fixation assay. Active fractions were further fractionated using gel filtration. Monosaccharide compositions and linkage analyses were determined for the relevant fractions. Polysaccharides were shown to be of the pectin type, and largely contain arabinogalactan, rhamnogalacturonan and homogalacturonan structural features. The presence of arabinogalactan type II features as suggested by methylation analysis was further confirmed by the ready precipitation of the relevant polysaccharides with the Yariv reagent. An unusual feature of some of these polysaccharides was the presence of relatively high levels of xylose as one of its monosaccharide constituents. Purified polysaccharide fractions were shown to possess higher biological activity than the selected standard in the complement assay. Digestion of these polysaccharides with an endo-polygalacturonase enzyme resulted in polymers with lower molecular weights as expected, but still with biological activity which exceeded that of the standard. Thus on the basis of these studies it may be suggested that immunomodulating properties probably contribute significantly to the health-promoting effects of this medicinal plant.

2019

Anneke du Toit, Frank van der Kooy
Artemisia afra, a controversial herbal remedy or a treasure trove of new drugs ?
Journal of Ethnopharmacology Volume 244, 15 November 2019, 112127

Artemisia afra, a controversial herbal remedy or a treasure trove of new drugs ?

Abstract

Ethnoparmacological relevance : Artemisia afra is one of the most widely used herbal remedies in South Africa. This highly aromatic shrub is used to treat various disorders including coughs, colds, influenza, and malaria. Due to the long tradition of use and popularity of A. afra, it has been successfully commercialised and can currently be bought from various internet stores and pharmacies. The most notable indication is for the prophylaxis and treatment of Plasmodium falciparum infections. In 2013, the Medicine Control Council (MCC) of South Africa banned the sale of A. afra for the treatment of malaria because it lacks scientific evidence of efficacy. This resulted in a lawsuit being filed in 2017 against the MCC by an herbal company which claimed that artemisinin was responsible for A. afra’s antiplasmodial activity. At the time, no scientific literature reported that A. afra contained artemisinin.

Materials and Methods : This review aims to collate all available scientific literature regarding the phytochemistry and biological activity, focusing on antimalarial activity, of A. afra published from 2009 to 2019 and follows on our earlier review, which covered all literature until 2009. All scientific literature in English published between 2009 and June 2019 were retrieved from scientific databases (Scifinder scholar, Web of Science, Scopus, PubMed, Google scholar) and a number of books regarding medicinal plants in South Africa were also consulted.

Results : In the last decade very few compounds have been identified in A. afra, none of which were novel compounds. Based on all the tests that have been conducted using extracts and compounds of A. afra in a disparate variety of in vitro and in vivo bioassays, the results indicate only weak biological activity. The activity of extracts, and in some cases pure compounds, exhibited IC50 or MIC values of 1 000 – 10 000 fold less active than the positive controls. In contrast, and quite surprisingly, two randomised controlled trials were recently conducted (Schistosoma mansoni and Plasmodium falciparum infected patients) and although criticised based on design, execution, statistical analysis and ethical concerns, showed remarkably positive results.

Conclusions : Pre-clinical in vitro and in vivo animal experiments failed to yield any promising drug leads. However, if the recent randomised controlled trials can be independently replicated in well-designed and executed clinical trials it might indicate that A. afra contain powerful ‘prodrugs’. Future research on A. afra should therefore focus on reproducing the randomised controlled trials and on artificially metabolising A. afra extracts/compounds in order to identify the presence of any ‘prodrugs’.
Keywords : Artemisia afra, Plasmodium falciparum, malaria, artemisinin, randomised controlled trial, prodrugs.

***

Matthew R. Desrosiers, Melissa J. Towler, Pamela J. Weathers
Artemisia annua and Artemisia afra Essential Oils and Their Therapeutic Potential
Essential Oil Research (Trends in Biosynthesis, Analytics, Industrial Applications and Biotechnological Production), 2019, pp 197-209

Artemisia annua and Artemisia afra Essential Oils and Their Therapeutic Potential

Abstract

Known for its production of the antimalarial drug, artemisinin, Artemisia annua L. contains a plethora of other phytochemicals and is a rich source of essential oils. Oil content and compositions vary considerably among cultivars, change throughout plant development, and vary with the geographic region. Many of the oils have antimicrobial activity and repel insects. Although numerous oil constituents have therapeutic properties, the response varies with mode of oil delivery to the patient, affecting both bioavailability of other compounds and their therapeutic efficacy. Depending on type and concentration, some oil constituents are also toxic to livestock and humans. Here, the essential oil contents of mainly A. annua, but also its close cousin, A. afra, which also has antimalarial capability, are discussed in relation to variations in the plant and eventual cost-effective use for a number of different therapeutic purposes including for treatment of many parasitic and microbial diseases, some viral diseases, and a variety of cancers.

Keywords : 1,8-cineole Artemisinin Borneol Camphor Eucalyptol Malaria Pinene Thujone

Mis en ligne par La vie re-belle
 25/05/2020
 http://lavierebelle.org/proprietes-antivirales-et

 Documents

 Artemisia afra : A potential flagship for African medicinal plants ?
PDF 
 Elsevier
 Effect of the plant matrix on the uptake of luteolin derivatives-containing Artemisia afra aqueous-extract in Caco-2 cells
PDF 
 Journal of Ethnopharmacology
 Artemisia afra and Modern Diseases
PDF 
 Journal of Pharmacogenomics & Pharmacoproteomics
 Ethnopharmacology in overdrive : The remarkable anti-HIV activity of Artemisia annua
PDF 
 Journal of Ethnopharmacology

Bibliographie : Potentiel antiviral d’Artemisia annua L. et Artemisia afra Jacq.

Ce dossier regroupe les publications concernant le potentiel antiviral d’Artemisia annua L. et Artemisia afra Jacq.

Les articles 1

IMG: Bibliographie : Potentiel antiviral d'Artemisia annua L. Cet article présente et permet l’accès aux recherches publiées relatives aux propriétés antivirales, immunomodulatrices et immunoprotectrices d’Artemisia annua (...)
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