DPP4 and Insulin Protein: Drug Targets for a Formulated Polyherbal Combination of <i>Phyllanthus urinaria</i> L. and <i>Adhatoda vasica</i> Nees Against HFD–STZ‐Induced TIIDM in Swiss Albino Mice

Type II diabetes mellites (TIIDM) characterized by hyperglycemia, insulin resistance, insensitivity, and pancreatic β-cell atrophy has gained concern due to high rise in such cases globally. This study highlighted the therapeutic potency of a novel polyherbal formulation (PHF) of Phyllanthus urinaria and Adhatoda vasica Nees mice by in vitro, in vivo, and in silico analysis in high-fat diet (HFD)-streptozotocin (STZ)-induced Swiss albino. The findings showed significant inhibition of α-amylase and α-glucosidase activity of the PHF along with decreased blood glucose level, increased glycogen and serum insulin level, elevated mRNA expression of GIPR and GLP1R, GLUT2, GLUT4, INSR, INS1, INS2, TCF7L2, and Pdx1 in both low and high dose of PHF-treated mice as compared to HFD-STZ-induced diabetic mice. Western blot results also demonstrated augmented insulin protein level in both PHF-treated groups. Okanin and vomicine, identified from LCMS analysis as potent antidiabetic bioactive compounds bind to dipeptidyl peptidase 4 (DPP4) with a binding energy of -8.04 and -7.81 kcal/mol, respectively, as compared to standard drug metformin (-5.33 kcal/mol). Inhibition of DDP-4 by bioactives of PHF aids in enhanced secretion of incretion hormones leading to insulin secretion thereby established itself as a complementary and alternative therapeutics in the management of diet-induced TIIDM.