Investigation on Antibactarial Activity of Certain Natural Products

Abstract

Seed extracts of three different plants viz. Phoenix sylvestris, Tricosanthes dioica, and Syzygium cumini were screened for their antibacterial activity against various pathogenic bacteria. Extracts were prepared by microwave assisted extraction (MAE) method. Antibacterial activity of the seed extracts was investigated against nine bacterial strains by disc diffusion assay (DDA). Minimum inhibitory concentration (MIC) of potent extracts were also determined by broth dilution assay. The highest antibacterial potential was observed with ethanol extract of S. cumini seeds which inhibited 78% of tested microorganisms. Amongst the microorganisms tested, the most resistant was found to be Aeromonas hydrophila and the most susceptible was Salmonella paratyphi A. The phytochemical analysis of ethanol extract of S. cumini and P. sylvestris seeds revealed the presence of phenols, flavones, and alkaloids. The phytoconstituents of methanol extract of S. cumini seeds were separated by means of thin-layer chromatography (TLC). DDA of separated components was carried out and antibacterial activity was found in components having Rf value 0.59 and 0.52. Synergistic activity between these components was not observed. From this study it can be said that further investigation of methanol and ethanol extracts of S. cumini seeds and ethanol extract of P. sylvestris seeds can lead to development of novel antibacterial compound(s).