Evaluation of Antimicrobial Activity of Mentha piperita, Tragia involucrata (L) and Urtica massaica Used as Medicinal Plants in Tanzania

Aims: To evaluate antimicrobial activity of Mentha piperita, Tragia involucrata (L) and Urtica massaica used as medicinal plants in Tanzania.

Study Design: Experimental study was carried out by using 96 wells micro dilution method.

Place and Duration of Study: This study was conducted at Dodoma University, Dodoma-Tanzania, between April and July 2017.

Methodology: Minimum inhibitory concentration of plants extracts against the tested bacterial and fungal species was determined by using 96 wells micro dilution method.

Results: Plant extracts exhibited antimicrobial activity with MIC range of 1.56 mg/mL to 12.5 mg/mL. The highest activity was shown by M. piperita chloroform leaf extract, M. piperita methanol leaf extract, T. involucrate chloroform leaf extract, T. involucrate ethyl acetate leaf extract, U. massaica chloroform leaf extract and U. massaica methanol leaf extract with MIC value of 1.56 mg/mL against K. oxytoca, E. coli, S. typhi, C. neuforman and P. aeruginosa.

Conclusion: The extracts from M. piperita, T. involucrate and U. massaica exhibited antimicrobial activity at various degrees against seven tested Gram-negative bacterial and two fungal species namely S. kisarawe, S. typhi, E. coli, K. oxytoca, P. aeruginosa, K. pneumonia, P. mirabilis, C. neoformans and C. albicans respectively.