Investigation of phytoconstituents of Enicostemma littorale as potential glucokinase activators through molecular docking for the treatment of type 2 diabetes mellitus.

Glucokinase (GK) is an enzyme involved in synthesising glucose into glucose-6 phosphate and serves a crucial function in glucose sensing. Therefore, agents that induce GK activation could be used to treat T2DM. The present work has been carried out to investigate the GK activation potential of phytoconstituents of Enicostemma littorale through molecular docking. All the phytoconstituents have been screened through the Lipinski rule of 5, Veber's rule, and ADMET properties. From these initial screening, only Apigenin, Ferulic acid, Genkwanin, p-coumaric acid, Protocatechuic acid, Syringic acid, and Vanillic acid have been selected to perform molecular docking studies. The binding free energy and binding mode of the native ligand in the allosteric site of the enzyme have been considered the reference for the other molecules' validation. The native ligand has exhibited - 7.2 kcal/mol binding free energy, whereas; it has formed four hydrogen bonds with THR-228, LYS-169, ASP-78, and GLY-81. Based on these findings, the interactions of phytoconstituents have been justified. Apigenin, genkwanin, and swertiamarin exhibited - 8.7, - 7.5, and - 8.3 kcal/mol binding free energy, respectively, which indicates better enzyme activation than the native ligand. Swertiamarin has formed 08 hydrogen bonds with allosteric amino acid residues, which confirms the excellent enzyme activation by these phytoconstituents. We concluded that if we can isolate and consume the exact active phytoconstituents (GK activators) from this plant, we can use them effectively to treat T2DM. More GK activators can be developed by considering them as a natural lead moiety.