Antibacterial activity of the stem bark of Tieghemella Heckelii Pierre ex. A Chev against methicillin-resistant Staphylococcus aureus.

BACKGROUND: Tieghemella heckelii (Sapotaceae) is a medicinal plant used in Africa, particularly in Côte d'Ivoire for treating various diseases including infections. Identification of prospective antibacterial compounds from stem bark of this plant as a result of its medicinal virtue, led to screening activity against methicillin resistant bacteria. METHODS: Six extracts (hexane, chloroform, ethyl acetate, ethanol, methanol and sterile distilled water) were prepared and tested on methicillin resistant Staphylococcus aureus (MRSA) using broth microdilution method for activity assessment. From this experiment, the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the plant extracts were determined in sterile 96-well microplates in order to search for both bacteriostatic and bactericidal effects. Afterwards, data analysis was performed using GraphPad Prism5 software (One-way ANOVA and Turkey Multiple Comparison test). The results were then presented as Mean ± SD for experiment repeated three times. RESULTS: Four extracts (ethyl acetate, methanol, ethanol and sterile distilled water) showed credible potency, with strong, significant, and moderate growth inhibition of the MRSA tested. The MIC values which varied from 45 µg/mL to 97 µg/mL according to microbial phenotype, resolutely established the activity of the plant extracts. Additionally, the MBC values which varied, depending on the type of bacteria strain, revealed the bacteriostatic and bactericidal effects of the active extracts against Methicillin-resistant Staphylococcus aureus. CONCLUSION: The present study is a confirmation of the therapeutic potential of Tieghemella heckelii and its promising contribution to the discovery of a novel antibacterial drug pertaining to these resistant strains.

Antifungal Activity of Erigeron floribundus (Asteraceae) from Cote d'Ivoire; West Africa

Purpose: Erigeron floribundus is a reputed medicinal plant used in Cote d'Ivoire; West Africa for the treatment of skin disorders. The aim of this study was to evaluate the antifungal activity of this plant against fungi from human origin. Method: Dichloromethane; methanol 80and aqueous extracts from the leaves with stem were tested for their antifungal activity against 7 strains of dermatophytes (Epidermophyton floccosum; Microsporum canis; M. gypseum; M. langeronii; Trichophyton mentagrophytes; T. rubrum; T. soudanense) and one strain of the filamentous fungus; Scopulariopsis brevicaulis. The assays were performed using the agar dilution method at serial concentrations ranging from 2 to 0.06 mg/ml. Result: Only the dichloromethane extract exhibited an activity against Microsporum canis and a broad spectrum of good antifungal activity against all the remaining fungi tested.Conclusion: To the best our knowledge; this is the first report of the antifungal activity of Erigeron floribundus against a wide range of dermatophytes; including Microsporum langeronii and Trichophyton soudanense; the most frequent dermatophytes in Cote d'Ivoire. E. floribundus might be potential sources for improved traditional medicines or new antidermatophyte agents for the treatment of dermatomycoses

Antitrypanosomal and antiplasmodial activity of medicinal plants from Côte d'Ivoire.

The antitrypanosomal activity of 101 crude ethanol extracts derived from 88 medicinal plants from Côte d'Ivoire was determined in vitro using Trypanosoma brucei rhodesiense. Of those extracts 8 showed good activity (IC50 values < or =8 microg/ml), 37 revealed a weak activity (IC50 values between 25 and 8.1 microg/ml) and 56 did not show any activity at all (IC50 values >25 microg/ml). The extracts of Enantia polycarpa (Annonaceae) and Trichilia emetica (Meliaceae) were the most promising ones. Their IC50 values were 0.5 and 0.04 microg/ml, respectively, and the selectivity index 616 and 209, respectively. This is the first report of in vitro antitrypanosomal activity of these two plants. Their high activities render them candidates for the isolation of compounds which could develop into new lead structures for drug development programs against African trypanosomiasis. Seven of the tested extracts exhibited an antiplasmodial activity against K1 strain of Plasmodium falciparum with IC50 values below 4 microg/ml. The highest activity was found for Enantia polycarpa stem bark with an IC50 value of 0.126 microg/ml.