Resveratrol Appears To Protect Against Steroidogenesis Collapse Of Leydig Cell In Mice Fed High-calorie And High-cholesterol Diet

Background There are many clinical datum showing that metabolic syndrome(MetS) and each of its components have detrimental effects on male fertility, whichinclude hypogonadism and testosterone deficiency. Leydig cell is the main site forsteroidogenesis. SIRT1can regulate energy metabolism and also adjust spermatogenesis,which links energy metabolism to reproduction. Resveratrol is a natural compound andserves as an activator for SIRT1. It deserves further exploration to estimate theprotection conferred by resveratrol supplementation on Leydig cells steroidogenesis inhigh-calorie and high-cholesterol diet (HCD)-fed mice.Object To investigate the detrimental effects on Leydig cells steroidogenesis inmice fed with high-calorie and high-cholesterol diet and the possible protectionconferred by resveratrol supplementation.Methods Male C57BL/6J mice were fed high-calorie and high-cholesterol dietalone (HCD group) or with resveratrol supplementation (HCD+Res group) for18weeks.Male C57BL/6J mice fed standard diet without or with the same dose of resveratrolserved as controls. At the end of the experiment, body weight of each mouse wasmeasured. Blood samples were collected by excision of mice’s eyeballs until the micebled to death. Then two testis, epididymal adipose tissue and subcutaneous adiposetissue of each mouse were harvested and weighed. Serum lipids including TC, LDL-c,HDL-c and TG were quantified by enzymatic colorimetric methods. Serum T, LH andFSH concentrations were measured by radioimmunoassay. HE staining was used forobserving the morphological structures of hepatic and testicular tissue.Immunohistochemical staining detected testicular tissue of the expressions of3β-HSD and Ob-R. Western blotting and RT-PCR analysis were employed for detecting theexpressions of SIRT1, steroidogenic protein/enzymes and antioxidases in testiculartissue.ResultsBody weight, adipose weight and testis weightMice on HCD diet showed significant increases in the body weight and adipose weightin comparison to the animals in two control groups(P<0.01). Significant decreasesexisted in the body weight and adipose weight between HCD-fed mice with resveratrolsupplementation and HCD-fed alone(P<0.05). There were no significant variations inthe testis weight among these experimental groups.Serum lipids profile and hormonesSignificant increases were observed in serum TC, HDL-c(P<0.05) and LDL-c(P<0.01)in HCD-fed mice as compared to control group. Supplement resveratrol treatment hasno significant effect on serum lipid concentrations. Significant decreases in serum T andLH were induced in mice HCD-fed, in comparison to control group(P<0.05).Resveratrol supplementation improved the levels of serum T and LH in HCD-fed mice(P<0.05).Histological analysisThe morphological structures of hepatic tissue in mice fed with standard diet werenormal，while steatosis was observed in HCD group. Resveratrol supplementationmarkedly alleviated the damages. HE staining showed that the morphological structuresof the testicular tissue were all normal in the four groups. The average numbers ofLeydig cells were similar among these experimental groups. The expression of Ob-Rwas down-regulated in HCD group in comparison to control group and significantlyimproved by resveratrol supplementation(P<0.01).Expression of SIRT1in testicular tissueMice in HCD group showed a statistically significant down-regulation as compared tocontrol group(P<0.01). In the HCD+Res group, there were significant increases incomparison to HCD group(P<0.01). Expressions of steroidogenic protein/enzymesDramatical increases were observed in Mice of HCD group in mRNAs forStAR(P<0.01), P450scc, P45017αand17β-HSD(P<0.05), as compared to control group.Resveratrol supplementation improved the expressions of steroidogenicprotein/enzymes in mice on HCD diet.The protein expression of StAR and P450sccdemonstrated the similar trends (P<0.01).Expressions of antioxidases in testicular tissueCompared to control group, mice treated with HCD showed a statistically significantdown-regulation in the mRNA expression of MnSOD and GPx4, which could besignificantly improved by resveratrol supplementation(P<0.01)..Conclusion Resveratrol may attenuate detrimental effects on Leydig cellssteroidogenesis in HCD-fed mice, and its upregulations of antioxidant defensemechanisms, activation for SIRT1and impacts on the function of HPG axis may play arole in its protection.