Resveratrol Attenuates Obesity-related Inflammation And Oxidative Stress In Adipose Tissue And Protects Testicular Endocrine Function

Background In modern society, unhealthy lifestyles such as sedentary, excessive intake of energy can lead to an increasing incidence of obesity year by year. Obesity can induce a variety of pathological conditions, including hypogonadism. The present study suggests that chronic inflammation induced by obesity is an important mechanism of obesity-related diseases such as insulin resistance. Resveratrol have properties of anti-inflammatory and antioxidant stress, and its value in the treatment of obesity-related metabolic diseases is a hot spot of current research.Object To investigate the mechanism of resveratrol on obesity-related inflammatory and oxidative stress, and the protection on testicular endocrine function.Methods Thirty 6-week-old C57BL/6J male mice were randomly divided into four group: high-calorie and high-cholesterol diet group(59.5% maintaining materials, 0.5% cholesterol, 10% yolk powder, 20% cane sugar and 10% lard)(HCD, n=8), high-calorie and high-cholesterol diet with resveratrol supplementation(given by intragastric administration at a dose of 400mg/kg/day)(HCD+Res, n=8); standard-diet-fed control group(maintaining materials same to HCD group)(Ctrl1, n=7); standard-diet-fed with resveratrol supplementation(Ctrl2, n=7). Diet and water were provided ad libitum for approximately 18 weeks. Mice were sacrificed by the removal of the eye ball. Then ①Epididymal adipose tissue was harvested and weighed. ②measure the concentration of serum testosterone by radioimmunoassay. ③Epididymal adipose tissue was embedded in paraffin, on the one hand, hematoxylin and eosin staining was used for morphological measurement. on the other hand, immunohistochemistry with macrophages special antibody F4/80 to observe the infiltration of macrophages. ④Western blotting to detect the protein expression of NF-κB and IκB-α, and antioxidants Sirt1, Mn SOD. ⑤RT-PCR were used for detecting the m RNA expression of Sirt1、Rel A、TNF-α、IL-1β and Mn SOD in epididymal adipose tissue.Results 1、 weight of mice and the level of serum TBody weight exited significant increased when compared with Ctrl group(p<0.05); however, HCD+Res group showed significant decreased when compared with HCD group(p<0.01). The weight of epididymal adipose tissue was consistent with body weight: HCD group showed a significant increase when compared with Ctrl group(p<0.05), resveratrol supplementation decreased the weight in HCD group(p<0.05). The concentration of serum T showed significant decreases in HCD group when compared with Ctrl group(p<0.05); Resveratrol supplementation increased the concentration of serum T in HCD+Res group when compared with HCD group(p<0.05).2、Morphology of adipose tissue HE staining showed that mean adipocyte area in HCD group were larger than Ctrl group; resveratrol supplementation decreased the area fed by HCD(p<0.01).3、Resveratrol decreased obesity-induced infiltration We used CLS from adipose tissue to stand for the infiltration of macrophages. Dates showed that CLS was more numerous in HCD group than standard-diet-fed control group(p<0.01), however, its density was dramatically decreased in HCD+Res group when compared with HCD group(p<0.01).We used RT-PCR and western blotting to analysis the effect of resveratrol on NF-κB signaling pathway. HCD group showed significantly elevated m RNA level of Rel A(p<0.01), as compared to standard-diet-fed control group. However, after treated with additional resveratrol, the m RNA level of Rel A showed significantly down-regulated(p<0.05). Changes in m RNA level of Rel A can also be confirmed by the protein expression levels of NF-κB and IκB-α. In accordance with m RNA level of Rel A, the protein expression level of NF-κB was significantly increased in HCD group and dramatically decreased with additional resveratrol supplementation(p<0.01). However, The protein expression of IκB-α showed an opposite tendency with the protein level of NF-κB. It decreased significantly in HCD group when compared to standard-diet-fed control group(p<0.01), and increased significantly with resveratrol supplementation in HCD+Res group(p<0.01). Dates showed that the relative m RNA expressions of two classic inflammatory cytokines TNF-α and IL-1β were elevated in HCD group, however, obviously decreased were showed in HCD+Res group as compared to HCD group(p<0.01).4、Resveratrol increased the expression of Sirt1 and Mn SOD The m RNA level of Sirt1 and Mn SOD were significantly decreased in HCD group when compared with standard-diet-fed control group(p<0.01). However, this HCD-induced decrease were markedly improved by resveratrol supplementation(p<0.01). Western blot analysis demonstrated that the similarly reduced translation of Sirt1 and Mn SOD protein existed in HCD mice when compared to standard-diet-fed control group(p<0.01), and this decrease was significantly improved by resveratrol supplementation(p<0.05).Conclusion Resveratrol can increase the concentration of serum T, alleviate obesity-related inflammation and oxidative stress in HCD mice. The findings suggest that resveratrol may have a potent therapeutic value for obesity-related hypogonadism.