IN VITRO ANTIMICROBIAL ACTIVITY OF CYNODON DACTYLON (L.) PERS. LEAF EXTRACTS. ANTIMICROBIAL ACTIVITY BY ZONE OF INHIBITION ESTIMATION

摘要

The present study was undertaken to evaluate in vitro antimicrobial activity of the successive leaf extracts of Cynodon dactylon in petroleum ether, ethyl acetate, acetone, ethanol, methanol and water, against various Gram positive & Gram negative bacterial strains using zone of inhibition. Both Agar well diffusion method & Agar disc diffusion method were used to evaluate the antibacterial efficacy. The microorganisms used in the test were - Escherichia coli, Proteus vulgaris, Staphylococcus aureus, Websiella pneumoniae, Pseudomonas aeruginosa, Shigella flexneri, Salmonella typhi, Salmonella paratyphi A, Salmonella paratyphi B, Bacillus subtilis, Streptococcus pyogenes, Vibrio cholerac and Enterobacter aerogenes. Two fungal strains - Candida albicans and Saccharomyces cerevisiae were also tested to evaluate the antifungal potential of the said plant extract. The reference antibiotics chloramphenicol & ampicillin (antibacterial); nystatin & clotrimazole and (antifungal) were also tested against these standard microorganisms used in the assay and the results were compared with that of the plant extracts.The results of the study revealed that all the seven successive extracts of the leaf powder of Cynodon dactylon ( L.) Pers. exhibited prominent antimicrobial and antifungal activity against all microorganisms used in the study. The nonpolar extracts i.e. petroleum ether, ethyl acetate and acetone showed the most significant antibacterial and antifungal activity against all tested organisms. The petroleum ether and ethyl acetate extracts showing maximum inhibition in the range of 8 mm -15 mm. This was closely followed by, acetone extract, which showed the inhibition in the range of 9 mm -13 mm.