Antibacterial and antifungal activity from flower extracts of Cassia fistula L.: An ethnomedicinal plant

Abstract

Since the advent of modern drug treatments, traditional medicine has greatly receded in occidental societies. Moreover, only a limited number of medicinal plants have received detailed scientific scrutiny; thereby prompting the World Health Organisation to recommend that this area be comprehensively investigated. The aim of the study is to assess the antimicrobial activity and to determine the zone of inhibition of extracts on some bacterial and fungal strains. In the present study, the microbial activity of hydroalcohol and chloroform extracts of flowers of Cassia fistula Linn. (an ethnomedicinal plant) were evaluated for potential antimicrobial activity against medically important bacterial and fungal strains. The antimicrobial activity was determined in both the extracts using agar disc diffusion method. Extracts were effective on tested microorganisms. The antibacterial and antifungal activities of solvent extracts(5, 25, 50, 100, 250μg/ml) of Cassia fistula were tested against 2 gram positive, 2 gram negative human pathogenic bacteria and 3 fungi respectively. The extracts showed broad spectrum of inhibition by showing antibacterial effect for both Gram positive and Gram negative human pathogen bacterial strains. Crude extracts of Cassia fistula exhibited moderate to strong activity against most of the bacteria tested. The tested bacterial strains were S. aureus, S. pyogenes, E. coli, P. aeruginosa, and fungal strains were A. niger, A. clavatus, C. albicans. The antibacterial potential of the extracts were found to be dose dependent. The phytochemical analysis of the plants were carried out. The antibacterial activities of the various parts of Cassia fistula were due to the presence of various secondary metabolites. Hence these plants can be used to discover bioactive natural products that may serve as leads in the development of new pharmaceuticals research activities.