Chardonnay grape seed flour alters expression of hepatic genes for lipid and glucose metabolism, inflammation, and leptin receptor (829.13)

Abstract

To determine whether flavonoid‐rich wine grape seed flour improves insulin sensitivity and glucose metabolism in obese mice, diet‐induced obese (DIO) mice were fed a HF diet supplemented with either 10% partially defatted Chardonnay grape seed flours (ChrSd) or microcrystalline cellulose (MCC, control) for 4 weeks. The 2‐h insulin and glucose areas under the curve were lowered by ChrSd indicating that ChrSd enhanced insulin sensitivity and improved glucose metabolism. ChrSd intake also reduced body weight gain, liver and adipose tissue weight, and plasma total and LDL‐cholesterol concentration despite a significant increase in food intake. Exon microarray analysis of hepatic gene expression revealed down‐regulation of genes related to gluconeogenesis, inflammation, triglyceride synthesis, and polyunsaturated fatty acid elongation, and up‐regulation of genes related to fatty acid oxidation, cholesterol and bile acid synthesis. The expression of hepatic leptin receptor was up‐regulated by the ChrSd diet supporting a role for leptin in the reduction of insulin resistance, inflammation, and hepatic steatosis. Analysis of the microarray data identified TCA cycle II, gluconeogensis, and glycolysis pathways as being differentially regulated by the ChrSd diet. In conclusion, Chardonnay grape seed flour ameliorates the effects of a HF diet on insulin resistance, hepatic lipid accumulation and glucose production, inflammation, and weight gain in DIO mice.