Comparative study of in vitro antimicrobial potential and phytochemicals of some medical plants

Abstract

Background: Plants in traditional healthcare services in West Africa were selected based on ethnobotanical data for this study. Aqueous and ethanol extracts from these plants’ parts were comparatively screened for phytochemicals and in vitro antimicrobial activity. Methods: The antimicrobial activity of five medicinal plants’ extracts (aqueous and ethanol) were evaluated against Proteus mirabilis (LHC201), Pseudomonas aeruginosa (LHC181) and Aspergillus fumigates (LUML56) using the agar-well diffusion protocol. Retailed chloramphenicol and griseofulvin were used as positive controls respectively. Phytochemicals and percentage yield were determined by modified standard methods. Results: The target bacteria showed varied degrees of susceptibility to both aqueous and ethanol extracts. A. fumigates was insensitive to the treatments. The ethanol extracts of the sampled plants’ parts showed better inhibitory performance against the target bacteria compared to aqueous extracts. Aqueous and ethanol extracts of Aframomum melegueta, Moringa oleifera and Cola nitida showed marginal difference in inhibitory activity with higher inhibition zones observed for the ethanol extracts of A. melegueta seed and M. oleifera pod against the target bacteria. Phytochemicals composition and density observed in extractants and plants’ parts also varied. Phenols were detected in both the aqueous and ethanolic extracts of C. nitida and C. acuminata, but appeared relatively richer in extracts of A. melegueta seeds and C. albidium fruits. C. nitida, C. acuminate and A. melegueta extracts were positive for flavonoids which were undetected in C. albidium fruits, M. oleifera seeds and pod extracts. No single extract had all the phytochemicals assayed. Conclusions: Screened extracts of medicinal plants’ parts used for this study showed promise antibacterial and resource for developing safer pharmaceutics. Optimization of the antibacterial potential of the extracts for commercial exploitation requires further studies. This study has provided information on the antibacterial property of C. albidum fruits which was hitherto underutilized for traditional medicine purpose.