Abstract: Diabetes mellitus has become one of the biggest health problems around the globe. Thus, in recent times, the demand for affordable and efficient antidiabetic medications has increased considerably. The present study aims to evaluate the antidiabetic activities of methanolic leaf extracts of endangered plants of western ghats. Enzymes in the intestine namely, alpha-glucosidase plays an important role in the digestion of carbohydrates and in controlling the glucose level in blood. α-Glucosidase inhibition bio-assay was conducted by following the standard protocol using Glucose Oxidase method with Acarbose as the standard and the absorbance was measured at 510 nm. In α-Glucosidase inhibition bio-assay, the plant samples Curcuma zedoaria, Syzygium travancorium stem and Plectranthus vettiveroides leaves showed inhibition activity against α-glucosidase with increased extract concentration. Among the three samples, S. travancorium stem extract was proven most antidiabetic hence making it a possible source in the preparation of antidiabetic drugs. The antidiabetic activity is directly proportional to the concentration of the sample extracts since the obtained inhibition values are increased with the increased concentration. S. travancorium, with higher inhibition activity, was observed to be the best source for antidiabetic activity among all the tested samples.

Keywords: Diabetes mellitus, α-Glucosidase, antidiabetic, inhibition activity, Western ghats, endangered plants

| DOI: 10.17148/IARJSET.2022.9241