Ethnobotanical survey and in vitro antiplasmodial activity of plants used in traditional medicine in Burkina Faso

Antiplasmodial activity of botanical extracts against Plasmodium falciparum

The absence of a vaccine and the rampant resistance to almost all antimalarial drugs have accentuated the urgent need for new antimalarial drugs and drug targets for both prophylaxis and chemotherapy. The aim of the study was to discover effective plant extracts against Plasmodium falciparum. In the present study, the hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Citrus sinensis (peel), Leucas aspera, Ocimum sanctum, Phyllanthus acidus (leaf), Terminalia chebula (seed) were tested for their antimalarial activity against chloroquine (CQ)-sensitive (3D7) strain of P. falciparum which was cultured following the candle-jar method. Antimalarial evaluations of daily replacement of culture medium containing CQ and different plant crude extracts were performed on 96-well plates at 37°C for 24 and 48 h. Parasitemia was determined microscopically on thin-film Giemsa-stained preparations. Plant extracts were tested for their cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on human laryngeal cancer cell line (HEp-2) and normal cell line (Vero). Out of the 25 extracts tested, six showed good (IC(50) 4.76-22.76 μg/mL), 15 exhibited moderate (IC(50) 31.42-88.03 μg/mL), while four displayed mild (IC(50) > 100 μg/mL) antiplasmodial activity. The leaf ethyl acetate and methanol extracts of L. aspera; ethyl acetate, acetone, and methanol extracts of P. acidus; and seed acetone extract of T. chebula had good antiplasmodial activity (IC(50) = 7.81, 22.76, 9.37, 14.65, 12.68, and 4.76 μg/mL) with selectivity indices 5.43, 2.04, 4.88, 3.35, 3.42, and 9.97 for HEp-2 and >5.79, >2.20, >11.75, >3.41, >3.94, and >7.38 for Vero cells, respectively. These analyses have revealed for the first time that the components present in the solvent extracts of L. aspera, P. acidus, and T. chebula have antiplasmodial activity. The high antiplasmodial activity observed make these plants good candidates for isolation of anti-protozoal compounds which could serve as new lead structures for drug development.

Evaluation of 13 selected medicinal plants from Burkina Faso for their antiplasmodial properties

AIM OF THE STUDY

The aim of this study was to evaluate the antiplasmodial properties of 13 plants used against malaria in traditional medicine in Burkina Faso.

MATERIALS AND METHODS

In vitro antiplasmodial activity of dichloromethane, methanol and aqueous crude extracts obtained from vegetal samples collected in Burkina Faso was first evaluated on the Plasmodium falciparum 3D7 chloroquine-sensitive strain using a colorimetric method.

RESULTS

Thirteen extracts obtained from 8 different species were found to exhibit antiplasmodial activity (IC(50)<50 microg/ml). Five species demonstrated a moderate activity (15 microg/ml<IC(50)<50 microg/ml): Boswellia dalzielii (leaves), Waltheria indica (roots and aerial parts), Bergia suffruticosa (whole plant), Vitellaria paradoxa (bark) and Jatropha gossypiifolia (leaves). The best results were obtained with extracts from the Dicoma tomentosa whole plant, from Psorospermum senegalense leaves and from Gardenia sokotensis leaves. These extracts found to display promising antiplasmodial activity, with IC(50) values ranging from 7.0 to 14.0 microg/ml. The most active plant extracts were then tested for in vitro activity on the Plasmodium falciparum W2 chloroquine-resistant strain and also for in vitro cytotoxicity on normal human fibroblasts (WI-38) in order to determine the selectivity index.

CONCLUSIONS

Dicoma tomentosa (Asteraceae) and Psorospermum senegalense (Clusiaceae) appeared to be the best candidates for further investigation of their antiplasmodial properties, reported for the first time by this study.

Ethnopharmacological use of herbal remedies for the treatment of malaria in the Dangme West District of Ghana

AIM OF STUDY

Malaria is one of the most important diseases in the world. Because of the devastating nature of the disease there is an urgent need to develop new drugs or vaccines for the treatment, prevention and management of the disease. The objective of the present study was to collect and document information on herbal remedies traditionally used for the treatment of malaria in the Dangme West District of Ghana.

METHODS

Data was collected from 67 indigenous households in ten communities in the district using a validated questionnaire.

RESULTS

In total, 30 species of plants belonging to 28 genera in 20 families were reported to be used in the preparation of the herbal remedies. Mature leaves were the most (55%) common plant part used and 73.3% of the herbal remedies involved a single plant. Most of the herbal remedies were prepared by boiling and administered orally. The majority (47%) of the species of plants used were collected from their compounds or home gardens.

CONCLUSIONS

Knowledge about malaria and treatment practices exists in the study area. Herbal remedies were commonly used by people for the treatment of malaria because they were cost-effective. They are also more accessible. Many of the species of plants used have been documented for the treatment of malaria as well as investigated for their phytochemical and antimalarial and/or antiplasmodial activity confirming the results of previous studies as well as rationalization of their traditional use. Five species of plants used in the study area, namely, Bambusa vulgaris Schrad. ex J.C. Wendl. (Poaceae), Deinbollia pinnata Schum. &Thonn. (Sapindaceae), Elaeis guineensis Jacq. (Arecaceae), Greenwayodendron sp. (Annonaceae) and Solanum torvum Sw (Solanaceae), are documented for the first time for their use in the treatment of malaria. "The result of this study provides the basis for further pharmacological studies on the herbal remedies used".

Screening of Latin American plants for antiparasitic activities against malaria, Chagas disease, and leishmaniasis

In order to explore rationally the medical potential of the plant biodiversity of the Central and South American region as a source of novel antiparasitic molecules, a multinational Organization of American States (OAS) project, which included the participation of multidisciplinary research centers from Argentina, Bolivia, Colombia, Costa Rica, Guatemala, Nicaragua and Panama, was carried out during the period 2001-2004. This project aimed at screening organic plant extracts for antitrypanosomal, antileishmanial and antimalarial activities and subsequently isolating and characterizing bioactive molecules. Plants for antiparasitic screening were selected from a database of ethnomedical uses of Latin American plants (PlanMedia) based on the amount of biological and chemical information available in the literature. We report here the evaluation of 452 extracts from 311 plant species in vitro screens against Plasmodium falciparum, Leishmania mexicana, and Trypanosoma cruzi. Out of 311 species tested, 17 plants (5.4%) showed antiparasitic activities at IC(50) values < or = 10 microg/mL. The most active plants were Acnistus arborescens (L.) Schltdl. (Solanaceae) (leaf, EtOH, IC(50): 4 microg/mL) Monochaetum myrtoideum Naudin (Melastomataceae) (leaf, MeOH, IC(50): 5 microg/mL) and Bourreria huanita (Lex.) Hemsl. (Boraginaceae) (branch, EtOH, IC(50): 6 microg/mL). These were selectively active against P. falciparum, L. mexicana and T. cruzi, respectively.

Saponins and polyphenols from Fadogia ancylantha (makoni tea)

Three new saponins (1-3) and a known saponin, together with four known polyphenolic compounds, have been isolated from the fermented and dried leaves of Fadogia ancylantha (Makoni tea). The structures of compounds 1-3 were established by analysis of their spectroscopic data. Both an ethanol-water extract of F. ancylantha and its phenolic constituents showed significant free-radical-scavenging and antimicrobial activities. No cytotoxicity, as evaluated by analysis of hypodiploid nuclei in HUVEC cells using propidium iodide staining, was observed for either the plant crude extract or its constituents.

Traditional antimalarial phytotherapy remedies in herbal markets in southern Ghana

ETHNOPHARMACOLOGICAL RELEVANCE

Although traditional antimalarial plant remedies in herbal markets are a very important component of the health care system in Ghana this has not been previously studied to allow for the formulation of effective strategy for malaria control in Ghana.

AIM OF STUDY

The main objective of the present study was to collect and analyse data on the antimalarial plant remedies in herbal markets in southern Ghana.

MATERIALS AND METHODS

Herborists were interviewed using a validated questionnaire and species of plants were identified using a combination of field photo guides, local names and voucher specimens.

RESULTS

A total of 71 herborists (95.8% female) were interviewed. There were potential correlations between different parameters and variables such as ethnic groups, type of vendor and age-groups. The study revealed 29 species of plants belonging to 22 families being sold for the treatment of malaria. The detailed use of these plants is documented. The most frequently mentioned species of plants were Morinda lucida Benth., Indigofera sp. and Nauclea latifolia Sm. The majority (82.8%) of the plant materials were sold in the dried state and 6.9% were sold in fresh state. About 76.2% of the herbal remedies were sold throughout the year while 23.8% were scarce in the dry season. The cost of treatment of malaria using the herbal remedies ranged from 1 to 2 United States Dollars (USD).

CONCLUSION

Standardization of names and authentication of plant materials using organoleptic, phytochemical and DNA barcoding techniques as well as further research on efficacy, safety and dosage prescriptions for both fresh and dried plant materials being sold for the treatment of malaria in southern Ghana are needed.

Cassiarins C-E, antiplasmodial alkaloids from the flowers of Cassia siamea

Three new alkaloids, cassiarins C-E (1-3), and a new chromone, 10,11-dihydroanhydrobarakol (4), which showed moderate antiplasmodial activity against Plasmodium falciparum 3D7, were isolated from flowers of Cassia siamea, and the structures of 1-4 were elucidated by 2D NMR analysis and chemical transformation. Cassiarin D (2) was a dimeric compound consisting of 5-acetonyl-7-hydroxy-2-methylchromone and cassiarin C (1), and cassiarin E (3) was a dimer of cassiarins A and C (1).

In vitro antiplasmodial activity of plants used in Benin in traditional medicine to treat malaria

AIM OF THE STUDY

The aim of the study was to evaluate the in vitro antiplasmodial activity of crude extracts of 12 plant species traditionally used in Benin for the treatment of malaria in order to validate their use.

MATERIALS AND METHODS

For each species, dichloromethane, methanol and total aqueous extracts were tested. The antiplasmodial activity of extracts was evaluated using the measurement of the plasmodial lactate dehydrogenase activity on chloroquine-sensitive (3D7) and resistant (W2) strains of Plasmodium falciparum. The selectivity of the different extracts was evaluated using the MTT test on J774 macrophage-like murine cells and WI38 human normal fibroblasts.

RESULTS

The best growth inhibition of both strains of Plasmodium falciparum was observed with the dichloromethane extracts of Acanthospermum hispidum DC. (Asteraceae) (IC(50)=7.5 microg/ml on 3D7 and 4.8 microg/ml on W2), Keetia leucantha (K. Krause) Bridson (syn. Plectronia leucantha Krause) (Rubiaceae) leaves and twigs (IC(50)=13.8 and 11.3 microg/ml on 3D7 and IC(50)=26.5 and 15.8 microg/ml on W2, respectively), Carpolobia lutea G.Don. (Polygalaceae) (IC(50)=19.4 microg/ml on 3D7 and 8.1 microg/ml on W2) and Strychnos spinosa Lam. (Loganiaceae) leaves (IC(50)=15.6 microg/ml on 3D7 and 8.9 microg/ml on W2). All these extracts had a low cytotoxicity.

CONCLUSION

Our study gives some justifications for the traditional uses of some investigated plants.

Screening of medicinal plants from Reunion Island for antimalarial and cytotoxic activity

AIM OF THE STUDY

Nine plants from Reunion Island, selected using ethnopharmacology and chemotaxonomy, were investigated for their potential antimalarial value.

MATERIALS AND METHODS

Thirty-eight extracts were prepared by maceration using CH(2)Cl(2) and MeOH, and were tested for in vitro activity against the 3D7 and W2 strain of Plasmodium falciparum. The most active extracts were then tested for in vitro cytotoxicity on human WI-38 fibroblasts to determine the selectivity index. Those extracts were also investigated in vivo against Plasmodium berghei infected mice.

RESULTS

Most active of the extracts tested were the dichloromethane leaves extracts of Nuxia verticillata Lam. (Buddlejaceae), Psiadia arguta Voigt. (Asteraceae), Lantana camara L. (Verbenaceae), the methanol extracts from Aphloia theiformis (Vahl) Benn. (Aphloiaceae) bark, and Terminalia bentzoe L. (Combretaceae) leaves displaying in vitro IC(50) values ranging from 5.7 to 14.1mug/ml. Extracts from Psiadia, Aphloia at 200mg/(kgday) and Teminalia at 50mg/(kgday) also exhibited significant (p<0.0005) parasite inhibition in mice: 75.5%, 65.6% and 83.5%, respectively.

CONCLUSION

Two plants showed interesting antimalarial activity with good selectivity: Aphloia theiformis and Terminalia bentzoe. Nuxia verticillata still needs to be tested in vivo, with a new batch of plant material.

Comparative Analysis of the Essential Oils from two Asteraceous Plants Found in Nigeria, Acanthospermum Hispidum and Tithonia Diversifolia

The essential oils from two members of the Asteraceae ( Acanthospermum hispidum DC. aerial parts, and leaves of Tithonia diversifolia (Hemsley) A. Gray), growing wild in Osun State, Nigeria, have been characterised by combined gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses. Twenty-nine components have been fully identified and grouped into monoterpene hydrocarbons (22.2%), oxygenated monoterpenes (4.6%), sesquiterpenes hydrocarbons (58.2%) and oxygenated sesquiterpenes (10.8%) in A. hispidum. The main constituents of the oil were β-caryophyllene (28.0%), α-pinene (15.9%) and bicyclogermacrene (11.0%) among the hydrocarbon compounds, and bisabolol (8.9%) and carvacrol methyl ether (4.1%) among the oxygenated components. Tithonia diversifolia essential oil comprised seventeen components and was characterised by a predominant content of monoterpene hydrocarbons (87.9%), cis-β-ocimene (43.7%), α-pinene (28.6%) and limonene (12.0%) being the main compounds. Sesquiterpenes represented ca. 10% oil, as sum of hydrocarbons and oxygenated components. A new chemotype is established for T. diversifolia, while the Nigerian A. hispidum is being reported for the first time as a new source of essential oil with some distinction in composition from those of other sources.

Evaluation of Senegalese plants used in malaria treatment: focus on Chrozophora senegalensis

An ethnobotanical study was conducted in the Dakar area of Senegal to investigate the species used in the treatment of malaria. Seven plants are principally used: Cissampelos mucronata, Maytenus senegalensis, Terminalia macroptera, Bidens engleri, Ceratotheca sesamoides, Chrozophora senegalensis and Mitracarpus scaber. From a bibliographic study, it had been shown that the Cissampelos mucronata, Maytenus senegalensis and Terminalia macroptera have already been studied by several authors, and so only Bidens engleri, Ceratotheca sesamoides, Chrozophora senegalensis and Mitracarpus scaber were evaluated in the present study. For each plant, extracts were prepared with different solvents and tested in vitro on two chloroquine-resistant Plasmodium falciparum strains. Crude extracts from the leaves and the stems of Chrozophora senegalensis showed the best in vitro results. The IC(50) value of an aqueous extract of Chrozophora senegalensis was 1.6 microg/ml without cytotoxicity. The in vivo antiplasmodial activity of Chrozophora extracts was determined by both the oral and the intraperitoneal ways. The stages of Plasmodium cycle targeted by Chrozophora were then studied in vitro. These results could justify the traditional use of this plant in malaria treatment.

Monoterpene glycosides isolated from Fadogia agrestis

Six monoterpene glycosides were isolated from Fadogia agrestis. Their structures were elucidated using a combination of mass spectroscopy, 1D- and 2D-homo- and hetero-NMR spectroscopy and chemical analysis, and established as being derivatives of 2,6-dimethyl-2(E),6(Z)-octadiene-1,8-diol containing from two to four units of rhamnopyranose and, three of them, one or two additional units of glucopyranose. In three of the compounds an acyl group of 8-hydroxy-2,6-dimethyl-2(E),6(Z)-octadienoyl was found esterifying the O-2 position of one of the units of rhamnopyranose.

Are West African plants a source of future antimalarial drugs?

Ethnopharmacology is a very interesting resource in which new therapies may be discovered. In the case of malaria, two major antimalarial drugs widely used today came originally from indigenous medical systems, that is quinine and artemisinin, from Peruvian and Chinese ancestral treatments, respectively. There is an urgent need for the discovery of new drugs due to the critical epidemiological situation of this disease. New inexpensive therapies that are simple to use and that will limit the cost of drug research are good justifications for this ethnopharmacological approach. Therefore, the aim of this review is to empirically analyse plants that are used for antimalarial treatment in West Africa, and to determine those with real promising antimalarial activity. The major leads such as those extracted from Cochlospermum, Cryptolepsis, Guiera and Azadirachta have been highlighted. Indeed, some extracts seem to be promising in future research, but development of new isolation and characterization techniques, for designing new derivatives with improved properties need to be discussed.

Ethnobotanical survey and antibacterial activity of some plants used in Guinean traditional medicine

A total of 418 healers have been interviewed in Guinea, a coastal country of West Africa, ranging between 7 degrees 30 and 12 degrees 30 of northern latitude and 8 degrees and 15 degrees of western longitude. Plant species used by the local inhabitants to treat infectious diseases were identified using ethnobotanical, ethnographic and taxonomic methods. During these investigations, 218 plants were registered, of which the following were the most frequently used: Erythrina senegalensis, Bridelia ferruginea, Crossopteryx febrifuga, Ximenia americana, Annona senegalensis, Cochlospermum tinctorium, Cochlospermum planchonii, Lantana camara, Costus afer, Psidium guajava, Terminalia glaucescens, Uapaca somon and Swartzia madagascariensis. Most plants, and especially the leaves, were essentially used as a decoction. In order to assess antibacterial activity, 190 recipes were prepared and biologically tested, among which six showed activity (minimal inhibitory concentration<125 microg/ml) against Bacillus cereus, Mycobacterium fortuitum, Staphylococcus aureus, or Candida albicans, i.e., Entada africana, Chlorophora regia, Erythrina senegalensis, Harrisonia abyssinica, Uvaria tomentosa, and a mixture of six plants consisting of Swartzia madagascariensis, Isoberlinia doka, Annona senegalensis, Gardenia ternifolia, Terminalia glaucescens and Erythrina senegalensis.

Cassiarins A and B, Novel Antiplasmodial Alkaloids from Cassia siamea

Two novel alkaloids with an unprecedented tricyclic skeleton, cassiarins A (1) and B (2), have been isolated from the leaves of Cassia siamea, and the structures were elucidated on the basis of spectroscopic data. Cassiarin A (1) showed a potent antiplasmodial activity.

Plants used traditionally to treat malaria in Brazil: the archives of Flora Medicinal

The archives of Flora Medicinal, an ancient pharmaceutical laboratory that supported ethnomedical research in Brazil for more than 30 years, were searched for plants with antimalarial use. Forty plant species indicated to treat malaria were described by Dr. J. Monteiro da Silva (Flora Medicinal leader) and his co-workers. Eight species, Bathysa cuspidata, Cosmos sulphureus, Cecropia hololeuca, Erisma calcaratum, Gomphrena arborescens, Musa paradisiaca, Ocotea odorifera, and Pradosia lactescens, are related as antimalarial for the first time in ethnobotanical studies. Some species, including Mikania glomerata, Melampodium divaricatum, Galipea multiflora, Aspidosperma polyneuron, and Coutarea hexandra, were reported to have activity in malaria patients under clinical observation. In the information obtained, also, there were many details about the appropriate indication of each plant. For example, some plants are indicated to increase others' potency. There are also plants that are traditionally employed for specific symptoms or conditions that often accompany malaria, such as weakness, renal failure or cerebral malaria. Many plants that have been considered to lack activity against malaria due to absence of in vitro activity against Plasmodium can have other mechanisms of action. Thus researchers should observe ethnomedical information before deciding which kind of screening should be used in the search of antimalarial drugs.

In vitro antiplasmodial activity of 18 plants used in Congo Brazzaville traditional medicine

Sixty-six extracts of 18 plants commonly used by traditional healers in Congo Brazzaville for the treatment of malaria have been investigated for in vitro antiplasmodial activity. Ethanolic and dichloromethane extracts of 7 among the 18 studied plants were moderately active (10 microg/ml<IC(50)<50 microg/ml). These extracts concerned Cassia siamea (bark), Cogniauxia podolaena (root), Landolphia lanceolata (root and leaves), Millettia versicolor (leaves), Pseudospondias microcarpa (leaves), Uapaca paludosa (leaves) and Vernonia brazzavillensis (leaves). These results support their traditional use as antimalarial plants. The bark extract of Uapaca paludosa showed a good activity (<10 microg/ml) and the extracts from Quassia africana (root and leaves) even exhibited IC(50) values less than 1 microg/ml. Except for Quassia africana, for which the three solvents (water, ethanol and dichloromethane) present an effective extraction, no aqueous extract was highly active. The cytotoxicity of aqueous, DCM and ethanol extracts of Quassia africana was tested on KB cell lines.

Antioxidant and 15-lipoxygenase inhibitory activities of the Malian medicinal plants Diospyros abyssinica (Hiern) F. White (Ebenaceae), Lannea velutina A. Rich (Anacardiaceae) and Crossopteryx febrifuga (Afzel) Benth. (Rubiaceae)

The African flora contains numerous medicinal plants whose biological and chemical properties are incompletely known. Antioxidant and radical scavenging properties of plants are subject to intensive research. In the work described here, we have investigated the antioxidant activity of the plants Diospyros abyssinica (root bark), Lannea velutina (root bark and stem bark) and Crossopteryx febrifuga (seeds). Extracts of different polarity were assayed for radical scavenging activity, using the stable free radical diphenylpicrylhydrazyl, and for inhibition of enzymatic lipid peroxidation mediated by soybean 15-lipoxygenase. All plants investigated showed activity, but there were large differences between plants and between extracts. In general, Diospyros abyssinica and Lannea velutina were richer in antioxidants than Crossopteryx febrifuga. Lipophilic extracts were not active as radical scavengers, but did inhibit 15-lipoxygenase. Semipolar extracts (80% aqueous ethanol and methanol) of Diospyros abyssinica and Lannea velutina showed the highest activity both as radical scavengers and lipoxygenase inhibitors, and also gave the highest extract yields. These plants therefore appear to be excellent sources of antioxidants.

Antimalarial activity of Sida acuta Burm. f. (Malvaceae) and Pterocarpus erinaceus Poir. (Fabaceae)

Among strategies to combat malaria, the search for new antimalarial drugs appears to be a priority. Sheering for new antimalarial activities, four plants of the traditional medicine of Burkina Faso: Combretum micranthum, Khaya senegalensis, Pterocarpus erinaceus and Sida acuta, were tested in vitro on fresh clinical isolates of Plasmodium falciparum. The screening showed that Sida acuta has a significant activity (IC50 < 5 microg/ml), and Pterocarpus erinaceus has a moderate activity (5 microg/ml < IC50 < 50 microg/ml). Further chemical screening showed that the activity of the most active plant, Sida acuta, was related to its alkaloid contents.