Upregulation of PPAR-γ mediates the renoprotective effect of omega-3 PUFA and ferulic acid in gentamicin-intoxicated rats

Ferulic acid (FrA) is a natural product containing phenolic compounds. ω-3 PUFA is the major constituent of fish oil. The aim of this study was to investigate the renoprotective role of FrA and FO in gentamicin (GM)-induced nephrotoxicity in rats. Forty four male rats were divided equally into 4 groups: Control group, GM group, FrA + GM group and FO + GM group. Each of the treated groups was injected with GM (40 mg/kg) i.p. for 9 consecutive days. FrA (100 mg/kg) and FO (5 mL/kg) were given to rats orally daily for 10 days prior to GM and then concomitantly with GM for additional 9 days. Kidney function was assessed by serum BUN and creatinine, urinary albumin excretion and N-acetyl-beta-D-glucosaminidase (NAG) activity and histopathological examination. The anti-inflammatory property was evaluated by measuring renal resolvin E1 and gene expression of PPAR-γ. The antioxidant activity was indicated by renal catalase (CAT) activity. GM-induced nephrotoxicity was evidenced by the renal histopathological changes along with increased renal indices. Prior and concomitant treatment with FrA or FO ameliorated nephrotoxic effect of GM as indicated by the significant decrease of serum BUN and creatinine, urinary albumin excretion and urinary NAG activity. Both treatments significantly enhanced CAT activity and gene expression of PPAR-γ. Resolvin E1 was significantly elevated in FO but not in FrA group. FrA and FO proved anti-inflammatory and renoprotective effects, which could be through their PPAR-γ agonist activity. Because FrA and FO are natural products, they could provide a safe intervention strategy in cases of exposure to nephrotoxins.