Screening of Some Plants Used in the Cameroonian Folk Medicine for the Treatment of Infectious Diseases

The present study was designated to evaluated the antimicrobial activities of methanol, ethanol, hexane, ethyl acetate, aqueous, mixture methanol/water and ethanol/water extracts of Pentadiplandra brazzeana, Erythrina sigmoïdea, Petersianthus macrocarpus, Clerodendrum umbellatum , Sida acuta , Eleusine indica , Bridelia micrantha and Musanga cecropioides which are plants used as traditional folk medicine in Cameroon for the treatment of different infections and disorders as gastrointestinal disorders. The antimicrobial activities of the extracts against 17 laboratory strains belong to 15 bacterial species and 2 yeasts implicated in gastrointestinal disorders were evaluated based on the inhibition zone using the disc diffusion assay, minimal inhibition concentration and minimal bactericidal concentration values. 89.6% of the extracts tested have an inhibitory effect at 1.25 mg against at least one of the microorganism tested with the diameter of inhibition zone values ranging from 8 to 27 mm. 62.5% of the broader spectrum of antimicrobial activity of plant material was obtained with methanol extract. The most susceptible bacterium was Shigella flexneri and Enterobacter cloacae the most resistant. Ethanol/Water extract of Pentadiplandra brazzeana presented a good activity against Proteus vulgaris with MIC and MBC of 78 and 250 μg/ml respectively. The weak activity was obtained with Methanol extract of Musanga cecropioides against Klebsiella pneumonia. The results might explain the ethnobotanical use of the studied species for the treatment of gastrointestinal infections.