Molecular modeling of Ruellia tuberosa L compounds as a-amylase inhibitor: an in silico comparation between human and rat enzyme model

Inhibition of α-amylase is an important strategy to control post-prandial hyperglycemia. The present study on Ruellia tuberosa, known as traditional anti-diabetic agent, is being provided in silico study to identify compounds inhibiting α-amylase in rat and human. Compounds were explored from PubChem database. Molecular docking was studied using the autodock4. The interactions were further visualized and analyzed using the Accelrys Discovery Studio version 3.5. Binding energy of compounds to α-amylase was varying between -1.92 to -6.66 kcal/mol in rat pancreatic alpha amylase and -3.06 to -8.42kcal/mol in human pancreatic alpha amylase, and inhibition konstanta (ki) was varying between 13.12- 39460µM in rat and 0.67-5600µM in human. The docking results verify that betulin is the most potential inhibitor of all towards rat model alpha amylase and human alpha amylase. Further analysis reveals that betulin could be a potential inhibitor with non-competitive pattern like betulinic acid. In comparison, betulin has smaller Ki (0.67µM) than acarbose (2.6 µM), which suggesting that betulin is more potential as inhibitor than acarbose, but this assumption must be verified in vitro.