Incretin therapy is one of the most potential approaches in the treatment of diabetes. In contrast to markedly available drugs, the herbal incretin modulators have lesser side effects with low economic cost. The main aim of this work was to analyze the potential of previously reported DPPIV inhibitor, aqueous extract of Pueraria tuberosa tubers (PTY-2) as incretin hormones receptor agonist against streptozotocin (STZ)-induced diabetes.

Chronic diabetes was induced with STZ (65mg/kg bw) in rats for 60days and grouped into diabetic control and PTY-2. Expression of genes was assessed by PCR, IHC, and ELISA. Morphological analysis of tissue was observed using H & E stain. In silico molecular docking approach has been used to see the interaction of active phytochemicals of PTY-2 on the basis of their binding energy [kcal/mol] and dissociation constant [pM] using YASARA software. Interactive visualization was done using Discovery studio 3.0.

In comparison to diabetic control, the size and number of islet cells along with the plasma level of GLP-1, GIP, and pancreatic expressions of GLP-1R, GIP-R, Bcl2, and insulin were enhanced significantly after PTY-2 treatment. Through in silico molecular docking, tuberostan showed the best interaction for GLP-1R with binding energy at 8.15kcal/mol and dissociation constant at 1061624.125 pM. Puererone showed the best interaction for GIP-R with binding energy at 8.31kcal/mol and dissociation constant at 810381 pM.

In addition to previously studied DPPIV inhibitor, PTY-2 also acts as incretin receptors agonist and protects against STZ-induced diabetes by down regulating β cells apoptosis.