In vitro and in vivo antidiabetic activity, isolation of flavonoids, and in silico molecular docking of stem extract of Merremia tridentata (L.)

The antidiabetic activity of stem-ethanol extract (SE) and the flavonoid-rich fraction (FF) of Merremia tridentata (L.) were investigated on alloxan-induced diabetic mice. Apigenin, cosmosiin, and quercitrin are flavonoids isolated for the first time from stem extracts. In addition, cynaroside was found to be at the highest level in SE and FF with a percentage of 4.375% and 58.430%, respectively. The administration of SE (100 mg/kg) and FF (50, 75 mg/kg) daily for 20 days resulted in a better hypoglycemic effect than the reference drugs, glibenclamide (5 mg/kg), and metformin (10 mg/kg). Furthermore, SE and FF were shown to significantly improve the plasma lipid profiles at the end of the study. Docking's study suggests that cynaroside, cosmosiin, and quercitrin are the most desirable compounds for hypoglycemic effects in many antidiabetic targets. Especially, SE and FF showed strongly alpha-amylase and alpha-glucosidase inhibitory activities (IC50 = 1.61-1.72 mg/mL on alpha-amylase and IC50 = 0.24-0.44 mg/mL on alpha-glucosidase). Therefore, SE and FF of Merremia tridentata is a potential drug with antidiabetic and hypoglycemic action as indicated by in vivo, in silico, and in vitro studies.