In vitro α-glucosidase and α-amylase inhibition by aqueous, hydroalcoholic, and alcoholic extract of Euphorbia hirta L.

Abstract

Background: Euphorbia hirta L. (Euphorbiaceae), commonly known as Dudhani, is distributed in the warm region of India and China. Traditionally, it is used in respiratory and gastrointestinal disorders. In addition, the antidiabetic property of the plant was also reported in the literature. This study was designed to evaluate the effect of aqueous, hydroalcoholic, and methanolic extracts (MEHs) of E. hirta on α-glucosidase and α-amylase in vitro. Materials and Methods: Aqueous, hydroalcoholic, and MEHs of E. hirta were prepared as per application program interface. In α-glucosidase activity, α-glucosidase (0.1 μ/mL) and substrate, 2.5 mM p-nitrophenyl-α-D-glucopyranoside was used; absorbance was recorded at 405 nm. In α-amylase activity, α-amylase solution (1.0 μ/mL) and substrate, 0.25% starch were used, and absorbance was measured at 540 nm. The IC50values were calculated by linear regression. Results: All the extracts showed α-glucosidase inhibitory activity comparable to acarbose with MEH having highest inhibitory activity among tested extracts. The observed IC50values were 213.63, 146.9, 78.88, and 8.07 μg/mL for aqueous, hydroalcoholic, MEH, and acarbose, respectively. All the extracts have shown mild α-amylase inhibitory activity compared to acarbose. Lineweaver–Burk plot has shown that the MEH is a mixed noncompetitive inhibitor for α-glucosidase enzyme. Conclusion: The results from this in vitro study clearly indicated that MEH of E. hirta had strong inhibitory activity against α-glucosidase and mild inhibitory activity against α-amylase. It can be used for management of postprandial hyperglycemia with lesser side effects, and provide a strong rationale for further animal and clinical studies.