DPP4 and Insulin resistance: Berberine is known to act through several mechanisms, including insulin-mimetic activity; improving the action of insulin by triggering AMPK (5′ adenosine monophosphate-activated protein kinase); reducing insulin resistance through protein kinase C-dependent up-regulation of insulin receptor expression; causing glycolysis; and by enhancing GLP-1 (Glucagon-like peptide 1) secretion and regulating its release, and by inhibiting DPP-IV (Dipeptidyl peptidase-4) (30).