Abstract: AIM: To investigate the protective effects of sesamin combined with vitamin E on chemically-induced renal injury and its modulation of the expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in rats. METHODS: Twenty-eight Sprague-Dawley (SD) rats were used to establish kidney impaired model by using D-gal (180 mg·kg^-1·d^-1,i.p.) and AlCl₃ (15 mg·kg^-1·d^-1,i.g.) for 20 weeks. A single dose of either Ses (160 mg·kg^-1·d^-1) or VE (10 mg·kg^-1·d^-1) and combined dose of Ses+VE (160 mg·kg^-1·d^-1 and 10 mg·kg^-1·d^-1) were given to rats at 13^th week post-renal injury induction for 8 consecutive weeks, while control rats were given NS (5.0 mL·kg^-1·d^-1). Bilateral kidneys from each rat were isolated to determine wet weight, nitric oxide (NO) and malondialdehyde (MDA) contents, the activities of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) were also determined at the end of the experiment. Hematoxylin & eosin (HE) and Masson stain were used to observe the renal morphology and collagen deposition. Immunohistochemical technique and western blotting were employed respectively to detect the iNOS and eNOS expression. RESULTS: As compared with the model rats, the levels of NO, SOD and T-AOC were significantly increased, and the MDA content was decreased in rats treated with Ses and (or) VE. The positive expression of eNOS was apparently up-regulated by down-regulating the iNOS level and the effects of Ses plus VE was better than single Ses or VE group(P<0.05,P<0.01). CONCLUSION: The renoprotective effect ofsesamin combined with vitamin E on chemically-induced renal injury in rats could be associated with decrease in free radical generation, increase in anti-oxidant activity, promotion of eNOS, inhibition of iNOS activity, restoration of eNOS/iNOS balance, Ses plus VE treatment was more effective than Ses or VE given as a single treatment (monotherapy).

Key words: sesamin, vitamin E, kidney, iNOS, eNOS