West African Medicinal Plants Research Articles

Anti-malarial and Therapeutic Potential of Ethanolic Leaf and Root Extracts of Alstonia boonei Against Plasmodium berghei Infection in Mice

Introduction: The main objective of this research was to investigate the antimalarial therapeutic potential of the ethanolic extract of the leaves and roots of Alstonia boonei, a West African medicinal plant that is used for the traditional treatment of malaria, fever, and other parasitic diseases. There is a need to scientifically evaluate various plants utilized in the ancient treatment of diseases as they might be potential sources of new modern drugs; thus, the importance of this study is obvious. Methods: The extracts were subjected to in vivo antimalarial tests in mice in order to determine their efficacy against malaria infection. These materials exhibited dose–dependent antimalarial activity (P<0.05), as indicated by suppressive and curative effects on mice infected with doses of 100, 200, and 400 mg/kg body weights of the Plasmodium berghei malaria parasite. Results: The suppressive test of the extracts revealed a significant dose–dependent early infection suppression at P<0.05. Conclusion: Based on the results, the plant should be further examined to analyze its bioactive compounds and position it as a potential source of new and novel molecules for antimalarial drug development.

West African medicinal plants: a review of their antimalarial activity

Nowadays, the use of medicinal plants in the fight against malaria must be based on scientific results of safety and quality. However, reviews of the antiplasmodial activities of plants in West Africa in recent years are rare. This study analyzes scientific publications from 2010 to 2021 on plants traditionally used in antimalarial treatments in West Africa. A systematic search was carried out in the PubMed and google scholar databases using the following keywords: Malaria, Antiplasmodial activity, extract, medicinal plant, West Africa; for articles published from 2010 to 2021. These articles concern ethnobotanical studies, antiplasmodial tests, isolated molecules and toxicity tests. A total of 8 West African countries were explored and 54 papers from 2010 to 2021 were selected with 78 plants studied. Nigeria and Burkina Faso recorded more work with 28 and 7 papers respectively and studied more plants with 31, and 16 respectively. The most active extracts for in vitro tests are found in Nigeria with ethanolic extracts of Phyllanthus amarus and Ipomoea purpurea with respectively an Inhibitory Concentratin of 0.05 μg /mL and 0.06 μg / mL. The most active extract in vivo is found in Nigeria with the methanolic fraction of Parkia biglobosa with a 100% suppression rate at a dose of 100 mg/kg/Day. It is clear that the traditional West African pharmacopoeia is a potential source of effective phytomedicines for the management of malaria.

Biology, chemistry, and pharmacological activity of Kigelia africana (Bignoniaceae) and Garcinia kola (Clusiaceae) - a review.

Kigelia africana and Garcinia kola are two West African medicinal plants traditionally used to treat or alleviate various medical conditions such as skin ailments, respiratory disorders, and digestive problems. Phytochemical analyses indicated the presence of bioactive constituents, including flavonoids and phenolic acids, suggesting that the extracts of these two plants can interfere with reactive oxygen species-induced oxidative stress, inflammation, and microbial growth. This paper reviews the biochemical properties and the antioxidant, anti-inflammatory, and antibacterial activities of these two relevant West African medicinal plants.

Percentage Destabilization Effect of Some West African Medicinal Plants on the Outer Membrane of Various Bacteria Involved in Infectious Diarrhea.

Previous work stated that Khaya senegalensis, Anacardium ouest L., Pterocarpus erinaceus, Diospyros mespiliformis, Ocimum gratissimum, Manihot esculenta, Vernonia amygdalina Delile, and Daniellia oliveri have a great potential for the fight against infectious diarrhea. However, data on their antibacterial activity on strains of bacteria responsible for infectious diarrhea are not available. This study is aimed at elucidating the mechanism of action of the antibacterial effect of these plants on some bacterial strains responsible for diarrheal infections. The design of the study included first evaluating the degree of sensitivity of Salmonella typhimurium 14028, Escherichia coli ATCC 25922, Shigella spp., and Salmonella spp. strains to aqueous and hydroethanolic extracts of each plant, followed by the determination of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiotic power (Pa). This screening was completed with the evaluation of the possible mode of action of the extracts by testing the membrane permeability of these bacterial strains. The data collected indicate that the bacterial strains tested were sensitive to the extracts to varying degrees, except Cassia sieberiana DC and Pseudocedrela kotschyi extracts. For the active extracts, inhibition diameters ranged from 18.33 mm to 7 mm. With the exception of Escherichia coli, all strains were sensitive to the aqueous and hydroethanolic extracts of Anacardium occidentale. MICs vary between 3.37 and 25 mg/ml. Membrane permeability test data show that all active extracts affect the bacterial strains tested by attacking the stability of their outer membrane. For all active extracts, the high percentage of membrane destabilization of the bacteria is significantly (p < 0.05) better than that of cefixime used as a reference. Thus, it appears that these extracts can destroy Gram-negative bacteria and increase the fluidity and permeability of their cytoplasmic membrane. The knowledge of the mechanism of action of these extracts is an interesting contribution to the fundamental knowledge on the alternative that medicinal plants represent to antibiotics. These extracts can be used in the management of infectious diarrhea.

Antiproliferative effect of extracts and fractions of the root of Terminalia avicennioides (Combretaceae) Guill and Perr. on HepG2 and Vero cell lines

BackgroundTerminalia avicennioides Guill and Perr (Combretaceae) is an important West African medicinal plant. The plant is used locally against microbes and parasites in both humans and animals and studies have demonstrated its cytotoxicity potential. Thus, this study was carried out to test the cytotoxic effect of the extracts and fractions of the root of the medicinal plant Terminalia avicennioides Guill and Perr (Combretaceae) in two different cell lines.MethodsMethanol, ethanol, 30 % ethanol, hot water and cold water extracts and ethylacetate, hexane, chloroform, butanol and residual water fractions, were evaluated at 1000, 750, 500, 250, 100 and 50 µg/mL concentrations, with doxorubicin as positive control. The cells were incubated with the extracts for 48 h at 37 °C in a 5 % CO2 humidified incubator. The inhibition of cell viability, determined with the methyl blue thiazole tetrazolium bromide (MTT) assay, was used to assess the anti-proliferative effect of the extracts, in normal Vero Monkey kidney and human liver cancer (HepG2) cell lines.ResultsThere was a concentration-dependent inhibition of cell viability in both the HepG2 and Vero cell lines. For HepG2 cells, antiproliferative effect was highest for the hexane fraction (viability ranged from 19.63 ± 1.10 % to 70.30 ± 1.78 % for 1000 and 50 µg/mL, respectively. For Vero cells, the highest antiproliferative effect, at 1000 µg/mL, was with hexane fraction (cell viability 21.37 ± 3.50 %), while at 50 µg/mL the chloroform fraction demonstrated the highest effect (viability of 86.10 ± 1.95 %).ConclusionsThe extracts and fractions from the root of Terminalia avicennioides have antiproliferative effect on the Vero and HepG2 cell lines tested. However, the extracts and fractions were not more toxic to the HepG2 than to the Vero cells. The cytotoxic effect of stem-bark and leaf extracts could be evaluated in the future to determine its anticancer potential.

Evaluation of Anti-inflammatory, Anti-pyretic, Analgesic, and Hepatoprotective Properties of Terminalia macroptera

AbstractIn Mali, improved traditional medicines [“Médicaments Traditionnels Améliorés”] are prepared from traditionally used medicinal plants. Recently, the Department of Traditional Medicine has identified Terminalia macroptera Guill. &amp; Perr. (Combretaceae) as a potential candidate for an improved traditional medicine. T. macroptera is a West African medicinal plant used in Mali against various health disorders, with more than 30 different indications mentioned by traditional healers, including hepatitis, gonorrhea, fever, pain relief, and various infectious diseases (Helicobacter pylori-associated diseases). To date, validation of most of the biological activities of has been mainly carried out in vitro, except for antimalarial activities. In this study, the potential anti-inflammatory, antipyretic, analgesic, and hepatoprotective properties of T. macroptera were investigated in different murine models. Administration of T. macroptera ethanolic root and leaf extracts in rats significantly reduced pyrexia, pain, inflammation, and hepatic marker enzymes such as alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase in the different murine models used (p&lt;0.05). A phytochemical screening of T. macroptera revealed the presence of tannins, flavonoids, saponins, anthracene derivatives, sterols, triterpenes, and sugars in both leaf and root extracts as the main phytochemical compounds. This was confirmed by qualitative analysis, liquid chromatography coupled with high-resolution mass spectrometry. T. macroptera extracts demonstrated interesting in vivo antipyretic, analgesic, anti-inflammatory, and hepatoprotective activities. Therefore, T. macroptera should be proposed and further evaluated as a potential improved traditional medicine for the treatment of liver-related disorders and for the relief of pain and fever.

Enabling West African Herbal-Based Traditional Medicine Digitizing: The WATRIMed Knowledge Graph.

The purpose of this study is to describe the design and development of the first release of the West African Herbal based Traditional Medicine Knowledge Graph (WATRIMed). It is a resource containing Traditional Medicine (TM) related entities and linked with publicly available knowledge bases in order to facilitate bringing West African TM into the digital world. The core model comprises currently 556 concepts including 143 identified West African medicinal plants and 108 recipes used by tradi-practitioners to treat 110 diseases and symptoms which are commonly encountered in this part of the world.

Activité anti-toxoplasmose, screening phytochimique et étude de la cytotoxicité de l’extrait éthanolique 70% de Hunteria eburnea Pichon (Apocynaceae)

Hunteria eburnea is a medicinal plant used in traditional medicine in the Sassandra Region (Ivory Coast) in the treatment of malaria and skin diseases. The aim of this study is to study the inhibitory effect of 70% ethanolic extract of Hunteria eburneaa stem bark on Toxoplasma gondii, a protozoan parasite such as Plasmodium falciparum that causes toxoplasmosis. The 70% ethanolic extract was obtained from the parts of the plant that are used by traditional health practitioners in the Haut-Sassandra Region (Ivory Coast).The 70% ethanolic extract of Hunteria eburnea stem bark revealed high anti-Toxoplasma gondii activity with an estimated IC50 of 0.72 mg / mL and no cytotoxicity to HFF cells. (Human Foreskin Fibroblasts). Also, the phytochemical screening of this extract revealed the presence of sterols / triterpenes as well as alkaloids. This result indicates a promising source of new anti-Toxoplasma drugs from Hunteria eburnea, a West African medicinal plant.

Activity of selected West African medicinal plants against Mycobacterium ulcerans disease

Activity of selected West African medicinal plants against Mycobacterium ulcerans disease

In Vitro Activity of Selected West African Medicinal Plants against Mycobacterium ulcerans Disease.

Buruli ulcer (BU) is the third most prevalent mycobacteriosis, after tuberculosis and leprosy. The currently recommended combination of rifampicin-streptomycin suffers from side effects and poor compliance, which leads to reliance on local herbal remedies. The objective of this study was to investigate the antimycobacterial properties and toxicity of selected medicinal plants. Sixty-five extracts from 27 plant species were screened against Mycobacterium ulcerans and Mycobacterium smegmatis, using the Resazurin Microtiter Assay (REMA). The cytotoxicity of promising extracts was assayed on normal Chang liver cells by an MTT assay. Twenty five extracts showed activity with minimal inhibitory concentration (MIC) values ranging from 16 µg/mL to 250 µg/mL against M. smegmatis, while 17 showed activity against M. ulcerans with MIC values ranging from 125 µg/mL to 250 µg/mL. In most of the cases, plant extracts with antimycobacterial activity showed no cytotoxicity on normal human liver cells. Exception were Carica papaya, Cleistopholis patens, and Polyalthia suaveolens with 50% cell cytotoxic concentrations (CC50) ranging from 3.8 to 223 µg/mL. These preliminary results support the use of some West African plants in the treatment of Buruli ulcer. Meanwhile, further studies are required to isolate and characterize the active ingredients in the extracts.

In Vitro Anti-Infective Screening Of Selected West African Medicinal Plants

Individual or whole parts of Persea Americana, Caesalpinia bonduc and Caesalpinia pulcherrima have been traditionally used for the treatment of various infectious diseases in West Africa. Methanolic extracts and fractions of these plants were screened for in vitro activity against L. donovani (promastigotes, axenic amastigotes and intracellular amastigotes in THP1 cells), T. brucei, Plasmodium falciparum (chloroquine sensitive and chloroquine resistant strains) and selected pathogenic microbes. With IC50 values less than 10 µg/mL, the extracts exhibited selective antileishmanial activity against, L. donovani Amastigote, and less potent effects against L. donovani Promastigote, L. donovani Amastigote + THP, and T. brucei blood stage trypamastigotes. Fractions of P. Americana and C. pulcherrima showed strong activities against both chloroquine-sensitive and chloroquine-resistant strains of P. falciparum. With IC50 values ranging from 3.6 to 12 µg/mL, all fractions of C. pulcherrima exhibited significant antimicrobial activity especially against C. glabrata, C. krusei, S. aureus and P. aeruginosa (IC50 < 8 – 81 µg/mL). Crude extracts of P. Americana showed activity against C. glabrata, S. aureus and P. aeruginosa (IC50 22 – 86 µg/mL). These findings are important scientific support for traditional uses of these plants in infectious diseases and provide a strong basis for further studies towards anti-infective drug discovery from the plants. Acknowledgements: This work was in part supported by USAID/HED grant 153 – 6200BF A-15 – 01 to Prof A. Falodun, University of Benin.

Prioritizing West African medicinal plants for conservation and sustainable extraction studies based on market surveys and species distribution models

Sub-Saharan African human populations rely heavily on wild-harvested medicinal plants for their health. The trade in herbal medicine provides an income for many West African people, but little is known about the effects of commercial extraction on wild plant populations. Detailed distribution maps are lacking for even the most commonly traded species. Here we combine quantitative market surveys in Ghana and Benin with species distribution models (SDMs) to assess potential species’ vulnerability to overharvesting and to prioritize areas for sustainable extraction studies. We provide the first detailed distribution maps for 12 commercially extracted medicinal plants in West Africa. We suggest an IUCN threat status for four forest species that were not previously assessed (Sphenocentrum jollyanum, Okoubaka aubrevillei, Entada gigas and Piper guineense), which have narrow distributions in West Africa and are extensively commercialized. As SDMs estimate the extent of suitable abiotic habitat conditions rather than population size per se, their output is of limited use to assess vulnerability for overharvesting of widely distributed species. Examples of such species are Khaya senegalensis and Securidaca longipedunculata, two trees that were reported by market vendors as becoming increasingly scarce in the wild. Field surveys should start in predicted suitable habitats closest to urban areas and main roads, as commercial extraction likely occurs at the shortest cost distance to the markets. Our study provides an example of applying SDMs to conservation assessments aiming to safeguard provisioning ecosystems.

ChemInform Abstract: The Uniqueness and Therapeutic Value of Natural Products from West African Medicinal Plants. Part 3. Least Abundant Compound Classes

AbstractReview: 156 refs.

The uniqueness and therapeutic value of natural products from West African medicinal plants, part II: terpenoids, geographical distribution and drug discovery

In this review series, an attempt has been made to give indepth coverage of natural products derived from West African medicinal plants with diverse biological activities.

The uniqueness and therapeutic value of natural products from West African medicinal plants, part III: least abundant compound classes

In this review, a continuation of our in-depth coverage of natural products derived from West African medicinal plants with diverse biological activities has been given.

The uniqueness and therapeutic value of natural products from West African medicinal plants. Part I: uniqueness and chemotaxonomy

This review gives an in depth coverage of the natural products derived from West African medicinal plants with diverse biological activities.

In vitro activity of extracts and isolated polyphenols from West African medicinal plants against Plasmodium falciparum

The aim of the study was to screen 11 selected traditional medicinal plants from West Africa for their in vitro antiplasmodial activity in order to determine the activity of single and of combination of plant extracts and to examine the activity of isolated pure compounds. Ethanolic and aqueous extracts of the 11 selected plants and pure compounds from Phyllanthus muellerianus and Anogeissus leiocarpus were tested in vitro against Plasmodium falciparum 3D7. Proliferation inhibitory effects were monitored after 48 h. Among the plants and pure compounds investigated in this study, geraniin from P. muellerianus, ellagic, gentisic, and gallic acids from A. leiocarpus, and extracts from A. leiocarpus, P. muellerianus and combination of A. leiocarpus with P. muellerianus affected the proliferation of P. falciparum most potently. Significant inhibitory activity was observed in combination of A. leiocarpus with P. muellerianus (IC(50) = 10.8 μg/ml), in combination of A. leiocarpus with Khaya senegalensis (IC(50) = 12.5 μg/ml), ellagic acid (IC(50) = 2.88 μM), and geraniin (IC(50) = 11.74 μM). In general growth inhibition was concentration-dependent revealing IC(50) values ranging between 10.8 and -40.1 μg/ml and 2.88 and 11.74 μM for plant extracts and pure substances respectively. Comparison with literature sources of in vivo and in vitro toxicity data revealed that thresholds are up to two times higher than the determined IC(50) values. Thus, the present study suggests that geraniin from P. muellerianus; ellagic acid, gallic acid, and gentisic acid from A. leiocarpus; and combination of extracts from A. leiocarpus with either P. muellerianus or K. senegalensis could be a potential option for malaria treatment.

Erythrophleum africanum Afzel. (Caesalpiniaceae), an African toothpick: Phytochemical screening, total flavonoid content and antioxidant activity

Erythrophleum africanum is an endangered West African medicinal plant because of the large-scale use of its stems as toothpicks. Phytochemical screening (preliminary test and thin layer chromatography (TLC) method), a quantitative analysis of total flavonoids, anthocyanidins and radical scavenging activity (2,2’-diphenyl-1-picrylhydrazyl (DPPH) method) of stems of E. africanum were undertaken. The study shows that the quantification of the phenolic compounds (flavonic aglycones and anthocyanidins) and the assessment of the antioxidant activity put in evidence that in spite of the weak percentage (0.05%) of total flavonoids in the stem of E. africanum, the flavonoids are responsible to 94.46% of its antioxidant propriety. Key words: Erythrophleum africanum, total flavonoids, toothpick, antioxidant activity, 2,2’-diphenyl-1-picrylhydrazyl (DPPH).

In vitro inhibitory effect of West African medicinal and food plants on human cytochrome P450 3A subfamily

Aim of the study In Africa, medicinal plants are used intensively and concomitantly with allopathic medicines in the treatment of opportunity diseases by many patients or by healthy person to prevent diseases. However, there is little information about the interactions between medicines and botanical products used currently in West Africa area. Therefore, the aim of the present investigation is to study the effect of some plant products on CYP3A4, CYP3A5 and CYP3A7, three individual enzymes of CYP3A subfamily, in vitro. Materials and methods Teas and ethanolic extracts of medicinal, food and co-administered plants were evaluated on CYP3A4, CYP3A5 and CYP3A7 individual enzymes in vitro using fluorometric assays. Results Extracts of adjuvant plants such as Aframomum cuspidatum, and Aframomum melegueta, as well as one medicinal plant ( Harrisonia abyssinica) inhibited CYP3A4, CYP3A5 and CYP3A7 activity more than 90%. Phyllanthus amarus showed high inhibition of CYP3A5 and CYP3A7. Food plants (S olanum macrocarpon and Talinum triangulare) inhibited CYP3A4 and CYP3A5 less than 20%. Conclusion These results indicate that plants tested in this study affect in vitro the activity of the main three CYP3A subfamily enzymes. These active plants could interfere with the metabolism at phase I of conventional drugs in vivo as well act as pharmacoenhancers in herbal mixtures.

Acute oral toxicity test and phytochemistry of some west african medicinal plants

Although there is increased acceptance and utilization of medicinal plants worldwide, many are used indiscriminately without recourse to any safety test. Thus, the need for toxicity tests to determine the safe dose for oral consumption. LD50 and phytochemistry of four medicinal plants of West Africa were investigated. Thirty male and non pregnant female Swiss albino mice weighing 20grams each were used for this study. They were divided into the Control (C), Oldenlandia corymbosa L. aqueous leaf-extract treated (OCG), Parquetina nigrescens aqueous leaf extract treated (PNG), Hybanthus enneaspermus aqueous leaf extract treated (HEG), Ficus carica leaf extract treated (FCG) and Sesamum indicum aqueous seeds extract treated group (SIG). Each group except the control was further divided into four sub-groups of six mice each, and were administered orally, graded doses (SI; 1, 2, 4 and 8, PN; 2.5, 5, 10 and 20, OC; 5, 10, 20 and 40, FC; 1, 2, 4 and 8, HE; 4, 8, 16, 32) of the aqueous extract of each plant (g/kg body weight) after 12 hours fasting. The dry aqueous leaf extracts of HE, OC, PN, FC all have dark brown colour and pH ranging from 6.1 to 7.2 while the seed extract of SI has a light brown color with pH of 7.0. Flavonoids, cardiac glycosides, anthocyanosides, saponin, and reducing sugar were present in all extracts, while cyanogenic glycoside was present only in HE. LD50 determination results obtained using Thompson and Finney methods were as follows; OC; 14.14 +/- 0.27 and 10.56 +/- 0.20, PN; 12.60 +/- 0.10 and 13.10 +/- 0.10, HE; 8.14 +/- 0.30 and 8.24 +/- 0.35, FC; 3.36 +/- 0.26 and 4.00 +/- 0.04, SI; 4.00 +/- 0.10 and 3.10 +/- 0.22 respectively (LD50 values are in g/kg body weight. The results of this study have provided an oral LD50 from where a safe dose can be chosen for further research into the merits of the consumption of these medicinal plants.