In Vitro Antimicrobial Activity of Stevia Rebaudiana Bertoni Leaves

Purpose: The aim of the present study was to investigate antimicrobial activity of the various extracts of Stevia rebaudiana leaves.
Method: Stevia rebaudiana Bertoni leaves were extracted in water, methanol, ethyl acetate and hexane and their antimicrobial activities were examined against few selected microorganisms including B. subtilis, S. aureus, M. luteus, S. marcenscens, P. aeruginosa, B. megaterium, E. coli, P. vulgaris, Yeast, A. niger and R. oligoporus using cup plate method.
Results: Water extract of Stevia leaf showed activity against B. subtilis and S. aureus only. Methanol extract gave the highest zone of inhibition against P. aeruginosa whereas minimum zone of inhibition was found against S. aureus and yeast. B. megaterium and yeast were found to be highly susceptible towards ethyl acetate and hexane extracts, respectively whereas A. niger and B. subtilis were found to be least susceptible against ethyl acetate and hexane extracts, respectively. Hexane extract showed the highest activity against yeast among the tested microorganisms.
Conclusion: The study confirms the possible antimicrobial potentiality of the leaf extract of Stevia rebaudiana.