Abstract

ANTIMICROBIAL EFFICACY AND PHYTOCHEMICAL INVESTIGATION OF PONGAMIA PINNATA LINN PIERRE STEM

Sowjanya Pulipati*, R. Sampath, P. Srinivasa Babu, U. Eswar Kumar

Abstract

Since plants are used as therapeutic agents, the present study is designed to evaluate the antimicrobial activities of ethanolic extract of fresh stems of Pongamia pinnata Linn against selective Gram positive, Gram negative bacteria and fungi strains in-vitro. The Pongamia pinnata ethanolic extract (PPEE) was prepared by cold maceration. The preliminary phytochemical screening was carried out by standard protocols. Quantitative determination of tannin and flavonoid contents was carried. The antimicrobial efficacy of stems of Pongamia pinnata was carried by agar well diffusion method at concentrations of 250μg, 500 μg, 750 μg and 1000 μg against selective Gram positive pathogens such as Staphylococcus aureus, Bacillus subtilis, Bacillus megaterium,Enterococcus faecalis, Gram negative Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris and fungi Aspergillus niger. The MIC was performed by two fold broth dilution method and the range was found to be 0.97 mg/ml to 250 mg/ml. The PPEE possess appreciable levels of tannin and flavonoid contents, 39.7±2.6 mg of GAE/gm and 41.2±1.7 mg of rutin/gm of extract respectively. The plant extract was exhibited maximum activity against Bacillus subtilis (25.33±1.52mm) followed by Escherichia coli (24.33±0.57mm) and then against Bacillus megaterium (23.33±0.57mm). The plant also exhibited significant activity against Aspergillus niger (17.66±1.15mm). The MIC lies between 31.2 to 62.5 mg/ml. The results in the study indicate that the antimicrobial activity depends upon the type of bacteria used for the study. This study evaluated the antimicrobial activity of PPEE. The crude extract of the plant showed significant activity against tested organisms. This study also showed that the plant could be a potential source for new antimicrobial agent.

Keywords: Pongamia pinnata, antimicrobial, agar well diffusion.