Protective effect of resveratrol on renal damage in spontaneously hypertensive rats and the related mechanisms

Objective To investigate the protective effect of resveratrol (RSV) on renal damage in spontaneously hypertensive rats (SHR) and the related mechanisms on interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1). Methods Twelve male spontaneously hypertensive rats were randomly divided into two groups: model group (SHR, n＝6）and RSV group (RSV, n＝6). Six male Wistar-Kyoto rats served as control group (WKY, n＝6). RSV (20 mg·kg-1·d-1) or vehicle were gavaged for 20 weeks. Microalbuminuria and urinary β2-microglobulin were determined by urine collection from 8:00 to 16:00 at 20th week. Scr, BUN and the renal pathological changes were measured after 20 weeks. Immunohistochemistry staining of fibronectin, collagenⅠ, IL-6 and ICAM-1 were used to analysis the changes of renal fibrosis and inflammation. Real-time PCR and Western blotting were used to measure the expression of IL-6 and ICAM-1 in kidneys. Results Compared with the control group, SHR significantly increased the level of microalbuminuria, urinary β2-microglobulin (P＜0.05), but they were diminished in RSV group (P＜0.05). The expressions of fibronectin, collagenⅠ, IL-6 and ICAM-1 by immunohistochemistry staining were augmented in SHR group, and were significantly inhibited in RSV group. Compared with the control group, the expressions of renal IL-6, ICAM-1 mRNA and protein were significantly increased in SHR group (P＜0.05), and RSV treatment significantly inhibited the up-regulation (P＜0.05). Conclusions RSV treatment can attenuate microalbuminuria, urinary β2-microglobulin and renal fibrosis in SHR rats. This renal protective effect is associated with the inhibition of IL-6, ICAM-1 expression, which suggesting that inflammation may be a potential therapeutic target of hypertensive renal damage.