In vitro Studies on the Inhibition of alpha-Amylase and alpha-Glucosidase by Root Extract Fraction of Kyllinga triceps (rottb)

Abstract

Alpha-amylase is a key enzyme in the pancreatic juice and saliva that breaks down large insoluble starch molecules into absorbable sugar molecules. Alpha-glucosidase in the small intestine catalyzes the final step in digestion of starch and disaccharides. In the present study, we sought to investigate in vitro inhibitory activity of methanolic extract of Kyllinga triceps against the two digestive enzymesαα-amylase and α-glucosidase by estimating total flavonoid content (TFC) and Total phenolic content (TPC). Methanolic extract of the roots of Kyllinga triceps was prepared by maceration. In-glucosidase activity, α-glucosidase (0.5 mg/mL) and substrate, 5 mM p-nitrophenyl-α-D-glucopyranoside was used; absorbance was recorded at 405 nm. In α-amylase activity, α-amylase solution (0.5 mg/mL) and substrate, 1% starch were used, and absorbance was measured at 540nm. The IC50 values were calculated by linear regression. All the extracts showedα α-amylase and α-glucosidase inhibitory activity in dose dependent manner and activity was comparable to acarbose. EAKT having highest inhibitory activity among tested extracts. The IC50 value of EAKT against α-amylase and α-glucosidase enzyme inhibitory activity was found to be 4.2 mg/mL and 3.7 mg/mL respectively and it was well comparable to that of standard, acarbose IC50 values (2.2 mg/mL and 1.62 mg/mL respectively). Among tested extracts, EAKT showed higher TPC (69.5 μg/mL) and TFC (14.22 μg/mL). The results from this study clearly indicated that Ethyl acetate fraction of Kyllinga triceps had strong inhibitory activity againstα α-amylase and α-glucosidase. High TPC and TFC values could be attributed to exert enzyme inhibitory action by Kyllinga triceps that can help in the regulation of glucose absorption and consequently glucose homeostasis. Kyllinga triceps can be proposed as an excellent alternative for management of post-prandial hyper glycaemia with lesser side effects.