Abstract

IN VITRO BACTERIA GROWTH INHIBITION POTENTIAL OF CRUDE EXTRACTS OF DIFFERENT PARTS OF RAUVOLFIA VOMITORIA AGAINST FIVE STANDARD STRAINS OF SELECTED HUMAN PATHOGENIC MICROBES

Oseni Lateef Adebayo*, Ajisope Bashir Mustapha Unique, Sunwiale Samuel Sunyazi

ABSTRACT

Rapid development of drug-resistant microbes has led to the continuous search for new bioactive lead compounds of natural origin. The antimicrobial activity of both ethanolic and methanolic extracts of various parts of Rauvolfia vomitoria were investigated by evaluating the effects of the leaf, stem, root and whole plant extracts against the growth of selected bacteria. Standard strains (ATCC) of Salmonella typhi, Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa and Proteus mirabilis were used as test organisms. Generally, the methanolic extracts showed the greatest inhibitory effects on the selected pathogens. Ciprofloxacin and 20% DMSO were used as positive and negative controls respectively. The most susceptible bacteria to the methanolic leaf extract was S. typhi; MIC (6.25 mg mL-1) while the methanolic root extract had the least MIC of 6.25 mg mL-1 on P. aeruginosa. Phytochemical screening of the various plant parts revealed the presence of alkaloids, flavonoids, phenols and cardiac glycosides in all the extracts. These phytochemicals have been previously implicated for antimicrobial activity. In conclusion, R. vomitoria leaf, stem, root and the combination thereof possess antibacterial compounds and thus may be pursued for subsequent development of new anti-typhoid and wound healing drugs.

Keywords: MIC, R. vomitoria, phytochemicals, growth inhibition, human pathogens