Antimicrobial potentials, phytochemical screening and determination of bioactive compounds from Three Indian folk medicinal plants
Aim: To investigate the antimicrobial efficacy of various solvents leaf extracts of Aegle marmelos, Plumbago zeylanica and Rhinacanthus nasutus against human pathogenic organisms such as Acinetobacter baumannii, Salmonella enteriditis, Bacillus cereus, Streptococcus pneumonia, Mycobacterium tuberculosis and Aspergillus fumigatous by agar well diffusion method. Background: Also, this is the first time report on MIC and MBC/MFC activities and identify the phytochemicals and functional groups using HPLC, GC-MS and FT-IR analysis. Objective: Minimum inhibitory concentration (MIC), minimum bactericidal (MBC/MFC) values were also carried out by the micro dilution method. Methods: Ethyl acetate extract of P. zeylanica showed better antimicrobial activity against the tested pathogens, especially for S. pneumoniae (40 mm) followed by ethyl acetate extract of R. nasutus (36 mm) against S. pneumoniae. While least inhibition was observed for aqueous extract of P.zeylanica against S. enteritis (10 mm). Results: The MIC ranged from 3.75 µg/ml to 60µg/ml and MBC/MFC 7.5 µg/ml to 60 µg/ml. Phytochemical analysis exhibited the presence of alkaloids, steroids, saponins, flavonoids, tannins, terpenes, phenolics and cardiac glycoside in all samples of selected plant extracts. Tannins, phenolics and glycoside were found only in the ethyl acetate extract of P.zeylanica. HPLC and GC-MS analysis of ethyl acetate leaf extract of P. zeylanica exposed ten major peaks and eleven compounds respectively. Chemical nature of the leaf extract was analysed by FT-IR spectrum. Conclusion: Ethyl acetate leaf extract of P. zeylanica showed better antimicrobial activity than other extracts as well as standard drugs. Therefore, this plant could be studied in detail for the identification of active biomolecules for antimicrobial agents.