DPP4 and diabetes mellitus: Flavonoids, which include flavanols, flavonols, flavones, flavanones, isoflavones, and anthocyanins, also possess DPP-4 inhibitory activity—for instance, the flavonoid-rich fraction of Pilea microphylla displayed antidiabetic efficacy in rats with diabetes generated by a high-fat diet and streptozotocin by lowering DPP-IV.