Evaluation of Malawian Vernonia glabra (Steetz)Vatke leaf and Securidaca longepedunculata (Fresen) root extracts for antimicrobial activities

The aqueous, ethanol and acetone crude extracts and dichloromethane, hexane, ethyl acetate and n-butanol fractions of the Securidaca longepedunculata roots and Vernonia glabra leaves were studied for their antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans using agar well diffusion method. The phytochemical presents, as well as the minimum inhibitory concentration (MIC) and minimum bacteriacidal/fungicidal concentration (MBC/MFC) of the extracts were also determined using standard methods. Results obtained indicated that Vernonia glabra leaves acetone extracts had excellent antimicrobial activity against E. coli, P. aeruginosa and ethanol extracts against S. aureus. The n-butanol fractions had the best activity against E. coli and S. aureus, dichloromethane fraction against P. aeruginosa and ethyl acetate fraction against C. albicans. For S. longepedunculate root ethanol extracts showed best activity against E. coli, acetone extract against P. aeruginosa and aqueous extract against C. albicans. The n-butanol fractions had best activity against E. coli, P. aeruginosa and C. albicans. These results verified the claims by traditional healers in Malawi that the plants extracts treats bacteria related ailments such as diarrhoea and could be a potential source for development of phytomedicine.