Evaluation of Antimicrobial and -Amylase Inhibitory Activity of Selected Medicinal Plants

Abstract

During this study we evaluated the a-amylase inhibitory activity and antimicrobial activity of different extracts of Psidium gujauva, Allium sativum, Withania sominfera, and Piper nigrum. Antimicrobial potential was observed against Escherichia coli and Staphylococcus aureus. The plant extracts were prepared with chloroform, ethanol, acetone and distilled water. Each extract was evaporated using rotary evaporator, under reduced pressure. Different concentrations (10, 20, 40, 60, 80, and 100 μg/ml) of each extract were made by using dimethyl sulfoxide (DMSO) and subjected to a-amylase inhibitory assay using starch azure as a substrate. The absorbance was read at 565 nm using spectrophotometer. Using this method, the percentage of a-amylase inhibitory activity of each extract was calculated. The aqueous, chloroform, acetone extracts of Withania sominfera showed maximum inhibit of a-amylase activity of 88.6, 78.9 and 85.4% respectively. However, maximum zone of inhibition against E. coli was observed by Withania sominfera ethanolic extract (22 mm) and against S. aureus was shown by Allium sativum chloroform extract (16 mm). Other extracts showed inhibition but it was not statistically significant. The phytochemical analysis revealed that all the extracts (chloroform, ethanol, acetone, aqueous) of the selected plants contained at least one of the metabolites among tannins, saponins, flavanoids, terpenoids, glycosides and alkaloids. Present findings suggested that extracts of many medicinal plants exhibit significant potential to inhibit a-amylase activities. Thus, ethnomedicines could be a cheaper and easy source of molecules for management of diabetes.

Keywords: a-Amylase, Inhibitory activity, Antimicrobial activity

Cite this Article:

Geetika Parasher, Neha Gupta, Mayank Raj Bhardwaj.Evaluation of Antimicrobial and a-Amylase Inhibitory Activity of Selected Medicinal Plants. Research and Reviews: Journal of Herbal Sciences (RRJoHS). 2015; 4(1): 15–28p.