Antimicrobial activity of six selected plants against some strains of pathogenic organisms

Abstract

Crude ethanolic extracts selected six Nigerian plants based on ethnobotanical reports of their antifungal and antibacterial actions were subjected to phytochemical and antimicrobial screening. All the six plants namely Acalypha fimbriata, Glaphae brevis, Vernonia amygdalina, Struchium sparganophora, Celosia argentea and Amaranthus spinosus were screened against strains of Candida albicans, Trichophyton metagophyte, Malassezia furfur, Aspergillus flavus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus. The seventy percent (70%) aqueous ethanolic extract of A. finbriata was found to possess greatest activities against the pathogenic fungi; C. albicans, T. metagophyte, M. furfur and A. flavus at minimum inhibitory concentration (MIC) of 50 mg/ml. While V. amygdalina and S. sparganophora showed better antibacterial activity of MIC values of 25 to 50 mg/ml than A. finbriata which exhibited wider spectrum of activity against the three pathogenic bacteria of MIC 100 mg/ml. The phytochemical screening revealed the presence of alkaloids, saponins and combined anthraquinones in A. finbriata which justifies its antimicrobial activities as portrayed in this test. The results of this work justify the ethnobotanical uses of these plants in traditional medicine in Nigeria.