In vitro leaves and twigs antimicrobial properties of Psidium guajava L. ( Myrtaceae )

Abstract

The current study aimed to investigate antimicrobial activity of methanol, ethanol, acetone, ethyl acetate and hot water (leaves and twigs fractions) Psidium guajava L. crude extracts against three bacteria and two fungi pathogens. Antimicrobial activity expressed by disc-diffusion assay (zone of inhibitions - ZIs), activity index (AI) and minimum inhibitory concentration (MICs) that were measured as reported in many investigations. Based upon the estimated ZIs, AI and MICs values, hot water twigs <1 cm diameter extract was the most potent against all tested microorganisms. The MICs value ranged between 4 and 7.2 mg/ml for bacteria, while, it was between 14.5 and 37.3 mg/ml for fungi. Moreover, ethyl acetate had the lowest antimicrobial activity compared to the other tested solvents. From the results obtained herein, it could be concluded that P. guajava serve as antibacterial and antifungal agent.