In vitro anti-microbial activities of some medicinal plants used in traditional remedies in southwestern part of Nigeria

Abstract

Ages before man discovered the existence of microorganisms, there has been a pre-knowledge of certain plants with their healing potentials, which possess anti-microbial properties. The present studies focused on the anti-microbial activities of the crude methanol leaf extracts of six medicinal plants, namely Moringa oleifera, Clerodendrum volubile, Petiveria alliacea, Secamone afzeli, Carpolobia lutea and Macrosphyra longistyla on some selected microorganisms, namely Escherichia coli ATCC 29929, Staphyloccocus aureus ATCC 29293, Streptococcus pneumoniae ATCC 49619, Pseudomonas aureus ATCC 27953,  Salmonella typhi ATCC 14028, Candida  albicans ATCC 10231, Malassezia furfur ATCC  14521 and Klebsiella pneumoniae ATCC 4252. The anti-microbial activities of these plants were compared with standard drugs: Lexotil (5μg), Furoxetil (30 μg), Loxaclav (30 μg), Oxavid (5 μg), Cefroden (10 μg), Cepharox (30 μg), Tetracycline (25 μg) and Gentamycin (10 μg). The in vitro anti-bacterial activity was performed by disc and agar well diffusion methods. All tests were performed in triplicates. Data collected were subjected to analysis of variance (ANOVA) and means were separated using the Duncan’s Multiple-Range Test (DMRT) at p < 0.05. Of all the plant tested, C. volubile had the best inhibitory effect against S. aureus (24.67±0.33 and S. pneumoniae (19.67± 0.33), which was better than the control drugs: lexotil (19.67±0.33, 15.33 ± 0.33) and oxavid (18.33±1.67). Petiveria alliacea (23.00±0.00) was the second best extract. As S. aureus was highly sensitive to C. volubile methanol extract, it could be used as an antibiotic against diseases caused by the pathogen.