Inhibition of dipeptidyl peptidase-4 (DPP4), antioxidant, antiglycation and anti-inflammatory effect of Ferulic acid against streptozotocin toxicity mediate nephropathy in diabetic rats

The protein glycation due to high blood glucose mediate release of inflammatory intermediate contributes in the development of diabetic nephropathy. Ferulic acid (FA) is a phenolic compound distributed in different foods as whole grains. Inhibitors of DPP4 improve GLP-1-mediated insulin secretion and inhibit liver gluconeogenesis. This study investigated the impact of FA as anti-inflammatory, antioxidant and antiglycation against streptozotocin-induced diabetic nephropathy in rats. This study was carried out on total ninety male rats allocated into six (each 15 rats); group I (control). All other animals (groups II–VI) were receiving 65 mg/kg STZ for induction of diabetes. Rats in group II (untreated diabetic). Rats in groups III–V were treated with FA (10, 20, 30 mg/kg bw) respectively, i.p. for 8 weeks. Group VI received 10 units insulin daily, sc. Fasting blood samples were subjected for assay of glycated hemoglobin (HA1c), serum MDA, aldose reductase, total antioxidant, DPP4 while kidney tissue subjected for assay of malondialdehyde (MDA), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), IL-1β and AGEs. Data obtained showed that, FA showed antioxidant activity by reducing MDA and enhancement antioxidant activity compared with untreated rats (p < 0.001) with dose dependence. In addition, FA reduced the activities of aldose reductase, DPP4 (p < 0.001), decreased IL-6, TNF-α and AGEs versus untreated rats (p < 0.001). Histological investigation revealed an improvement in the nephron structure in diabetic rat treated with FA versus untreated group. It was concluded that, FA possesses a potent antioxidant and anti-inflammatory and DPP4 inhibitor. For that, it was considered as a protective agent against the risk of diabetic nephropathy and can be used as alternative or complementary supplement.