Evaluation of phytochemical constituents and antimicrobial activity of Vernonia amygdalina leaf extracts

Abstract

Vernonia amygdalina is a shrub found in Nigeria, growing in backyard gardens and farmlands where it is popularly used as vegetable. The decoction has been used for bowel ailments and fresh cuts injuries. Aqueous, ethanolic, methanolic extracts of Vernonia amygdalina were examined for the phytochemical constituents and antimicrobial activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Salmonella typhi. Leaf extracts of the plant contained glycosides, alkaloids, saponins and tannins. The minimum inhibitory concentration (MIC) of the extracts against the test organisms is in the range of 15mg/ml to 45mg/ml. MIC values of 15mg/ml, 20mg/ml, 30mg/ml and 35mg/ml were recorded against methanol extract when the extract was assayed against E. coli, S. aureus, K. pneumonia and S. typhi respectively. The results of this study suggests that extracts of Vernonia amygdalina could serve as a source of chemotherapeutic agent against the infections associated with Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Salmonella typhi.