Study on the comparative antibacterial activity of Polyalthia longifolia (Debdaru) leaf extracts to some selective pathogenic bacterial strains

摘要

The increasing social and economic implications caused by pathogenic bacteria means there is a constant striving to develop near antibacterial agents. The present study was carried out in vitro to determine antibacterial activity of Polyalthia longiflia (Debdaru) leaf extracts with hexane, methanol and chloroform against six tested pathogenic bacteria viz. Bacillus subtilis, Sarcina lutea, Xanthomonas compestris, Escherichia coli, Klebsiella pneumonia and Pseudomonas sp. Using agar disc diffusion method and MIC determination test. The zone of inhibition against the tested bacteria was found ranging from 21.00 to 44.20mm. The highest zone of inhibition produced by the hexane, methanol and chloroform extracts ofPolyalthia longiflia at a concentration of 500μh/10μl against pathogenic bacteria i.e. Sarcina lutea were found 41.80mm, 44.20mm and 43.50mm respectively. The MIC values of all extracts against six tested bacteria were almost 15.625 μg/ 10μl. The plant leaf extracts can be used in the treatment of infectious diseases caused by them. Extensive investigation is needed to isolate the secondary metabolites from the extracts in order to test specific compounds for antimicrobial activity and the underlying mechanisms