Fatty acid elongases and desaturases play an important role in hepatic and whole body lipid composition. We examined the role that key transcription factors played in the control of hepatic elongase and desaturase expression. Studies with peroxisome proliferator-activated receptor a (PPARa)-deficient mice establish that PPARa was required for WY14643-mediated induction of fatty acid elongase-5 (Elovl-5), Elovl-6, and all three desaturases ), increased SREBP-1 and MLX nuclear content correlated with the induction of Elovl-5, Elovl-6, and D 9 D expression and the massive accumulation of monounsaturated fatty acids (18:1,n-7 and 18:1,n-9) in neutral lipids. Diabetes-and obesity-induced changes in hepatic lipid composition correlated with changes in elongase and desaturase expression. In conclusion, these studies establish a role for PPARa, LXR, SREBP-1, ChREBP, and MLX in the control of hepatic fatty acid elongase and desaturase expression and lipid

Anthocyanins are responsible for a variety of bright colors including red, blue, and purple in fruits, vegetables, and flowers and are consumed as dietary polyphenols. Anthocyanin-containing fruits are implicated in a decrease in coronary heart disease and are used in antidiabetic preparations. In the present study, we have determined the ability of anthocyanins, cyanidin-3-glucoside (1), delphinidin-3-glucoside (2), cyanidin-3-galactoside (3), and pelargonidin-3-galactoside (4), and anthocyanidins, cyanidin (5), delphinidin (6), pelargonidin (7), malvidin (8), and petunidin (9), to stimulate insulin secretion from rodent pancreatic beta-cells (INS-1 832/13) in vitro. The compounds were tested in the presence of 4 and 10 mM glucose concentrations. Our results indicated that 1 and 2 were the most effective insulin secretagogues among the anthocyanins and anthocyanidins tested at 4 and 10 mM glucose concentrations. Pelargonidin-3-galactoside is one of the major anthocyanins, and its aglycone, pelargonidin, caused a 1.4-fold increase in insulin secretion at 4 mM glucose concentration. The rest of the anthocyanins and anthocyanidins tested in our assay had only marginal effects on insulin at 4 and 10 mM glucose concentrations.

Much attention has been focused on food that may be beneficial in preventing diet-induced body fat accumulation and possibly reduce the risk of diabetes and heart disease. Cornelian cherries (Cornus mas) are used in the preparation of beverages in Europe and also to treat diabetes-related disorders in Asia. In this study, the most abundant bioactive compounds in C. mas fruits, the anthocyanins and ursolic acid, were purified, and their ability to ameliorate obesity and insulin resistance in C57BL/6 mice fed a high-fat diet was evaluated. Mice were initially fed a high-fat diet for 4 weeks and then switched to a high-fat diet containing anthocyanins (1 g/kg of high-fat diet) and ursolic acid (500 mg/kg of high-fat diet) for an additional 8 weeks. The high-fat diet induced glucose intolerance, and this was prevented by anthocyanins and ursolic acid. The anthocyanin-treated mice showed a 24% decrease in weight gain. These mice also showed decreased lipid accumulation in the liver, including a significant decrease in liver triacylglycerol concentration. Anthocyanin and ursolic acid treated mice exhibited extremely elevated insulin levels. Both treatments, however, showed preserved islet architecture and insulin staining. Overall, these data suggest that anthocyanins and ursolic acid purified from C. mas fruits have biological activities that improve certain metabolic parameters associated with diets high in saturated fats and obesity.