Modulation of NADPH oxidase and Nrf2/HO‐1 pathway by vanillin in cisplatin‐induced nephrotoxicity in rats

OBJECTIVES To investigate the protective effect of vanillin in cisplatin (CP)-induced nephrotoxicity in rats and elucidate the role of nrf-2 and its downstream antioxidant molecules. METHODS Rats received vanillin (100 mg/kg orally) for 10 constitutive days and CP (7.5 mg/kg, once, ip) on day 6 of vanillin administration. KEY FINDINGS Cisplatin suppressed body weight gain, increased serum urea and creatinine and renal malondialdehyde and nitric oxide while decreased renal total antioxidant capacity. Up-regulation of NADPH oxidase-4 (NOX-4) was marked in renal tissue of CP-treated rats along with down-regulation of the antioxidant genes (nuclear factor erythroid 2-related factor2 (NRF2) and haem oxygenase-1(HO-1)). Increased tumour necrosis factor-α and decreased interleukin-10 with increased myeloperoxidase activity were apparent in renal tissue of CP-treated rats along with marked tubular injury, neutrophil infiltration and increased apoptosis (caspase-3) and some degree of interstitial fibrosis. Vanillin prophylactic administration prevented the deterioration of kidney function, oxidative and nitrosative stress. It also suppressed NOX-4 and up-regulated NRF2 and HO-1 expression in renal tissue. Inflammation, apoptosis and tubular injury were also inhibited by vanillin. CONCLUSIONS The antioxidant mechanism by which vanillin protected against CP-induced nephrotoxicity involved the inhibition of NOX-4 along with the stimulation of Nrf2/HO-1 signalling pathway. These in turn inhibited inflammation and apoptosis.