Inhibition of Carbohydrate Hydrolysing Enzymes by Methanolic Extract of Couroupita Guianensis Leaves

Aim: The present study investigated the inhibitory effect of methanolic extract of Couroupita guianensis leaves (MCG) on carbohydrate hydrolysing enzymes and glucose uptake in isolated rat hemidiaphragm. Method: The effects of MCG at different concentrations (1.25-10mg) were carried out on carbohydrate hydrolysing enzymes namely porcine pancreatic αamylase, rat intestinal α-glucosidase and sucrase. The effect of MCG on glucose utilisation was evaluated by estimating glucose uptake in isolated rat hemidiaphragm. Results: MCG showed significant dose dependent on inhibition of rat intestinal sucrase (IC50 = 2.38 mg/ml), rat intestinal maltase (IC50 = 2.5mg/ml) and porcine pancreatic α-amylase. (IC50 = 2.86 mg/ml). Furthermore, the glucose uptake in isolated rat hemidiaphragm was increased (P<0.001) by MCG when compared to the control group. Conclusion: These results suggest that MCG has significant inhibitory activity on carbohydrate metabolizing enzymes and increases the peripheral utilization of glucose, indicating its probable therapeutic use as a potent antihyperglycemic agent.