Protective effect of silibinin on islet β cells in C57BL/6J mice fed a highfat diet

Abstract

To explore the eff ect of silibinin on β cells in C57BL/6J mice fed a high-fat diet and the possible mechanisms. A total of 18 male C57BL/6J mice at 3 weeks old were divided into a normal chow group (n=6), a high-fat diet group (n=6) and a high-fat diet plus silibinin group (n=6). Aft er intervention for 10 weeks, fasting blood glucose (FBG), fasting insulin (FINS), triglycerides (TG), alanine aminotransferase (ALT), creatinine (Cr) and blood urea nitrogen (BUN), lipid metabolism, antioxidant enzyme activities and apoptosis were evaluated. Pancreatic tissues were isolated to examine insulin-induced gene-1 (Insig-1), sterol regulatory element binding protein-1c (SREBP-1c) and fatty acid synthetase (FAS) mRNA and protein expression. Compared with the high-fat diet group, the function of insulin secretion was improved, and the level of blood glucose was decreased in the high-fat diet plus silibinin group (P<0.05). The levels of lipid content and oxidative stress and the rates of β cell apoptosis were lower in high-fat diet plus silibinin group than those in the high-fat diet group (both P<0.05). Simultaneously, the silibinin could promote the expression of Insig-1 and depress the expression of SREBP-1c and FAS (all P<0.05). Moreover, there was no significant difference in the levels of serum ALT, Cr and BUN among the 3 groups (all P>0.05). Silibinin can protect β cells of mice fed a high-fat diet, and this effect might be related to, at least partially, increase in its antioxidative ability through regulation of insig-1/SREBP-1c pathway. Moreover, silibinin is safe for long-term treatment.