Swertiamarin Contributes to Glucose Homeostasis via Inhibition of Carbohydrate Metabolizing Enzymes

Objective: Swertiamarin is a common secoiridoid found among the members of Gentianaceae. The present study aimed to establish the effectiveness of swertiamarin in achieving glucose homeostasis via inhibition of carbohydrate metabolizing enzymes by in-vitro and in-vivo studies. Materials and methods: Swertiamarin was obtained from dried whole plant samples of Enicostemma littorale Blume chromatographic fractionation over the silica gel column. Its effect on carbohydrate metabolizing enzymes viz., α-amylase and α-glucosidase were evaluated at 0.15 to 10 mg/mL in-vitro. The results were supplemented by anti-hyperglycemic studies in carbohydrate challenged mice pretreated with swertiamarin at a dose of 20 mg/kg body weight orally. Results: Swertiamarin was effective in inhibiting α-amylase and α-glucosidase with IC50 values of 1.29±0.25 mg/mL and 0.84±0.11 mg/mL, respectively. The studies in starch and sucrose challenged mice showed that swertiamarin effectively restricted the increase in the peak blood glucose level (BGL). The increase in peak BGL was 49 mg/dL and 57 mg/dL only in the treatment groups compared to 70 mg/dL and 80 mg/dL in untreated groups after 30 min in starch and sucrose-fed mice, respectively. Acarbose (10 mg/kg b.w.) also produced significant (p<0.01) blood glucose lowering response in both the models. Conclusion: Swertiamarin was effective in the achieving stricter glycemic control in carbohydrate challenged mice through the inhibition of carbohydrate metabolizing enzymes.