Grapefruit May Prevent Metabolic Syndrome

LONDON, OntarioNaringenin, the predominant citrus-derived flavonoid found in grapefruit, through its correction of many of the metabolic disturbances linked to insulin resistance, represents a promising therapeutic approach for metabolic syndrome, according to a published in the July issue of Diabetes. Mice fed a high-fat (western) diet become dyslipidemic, insulin and glucose intolerant, and obese. Four groups of mice (chow, western and western plus 1 percent or 3 percent, w/w naringenin) were fed ad libitum for four weeks. Very low-density lipoprotein (VLDL) production and parameters of insulin and glucose tolerance were determined. Researchers reported naringenin treatment of low-density lipoprotein receptor null (LDLR(-/-)) mice fed a western diet, corrected VLDL overproduction, ameliorated hepatic steatosis and attenuated dyslipidemia, without affecting caloric intake or fat absorption. Naringenin increased hepatic fatty-acid oxidation through a PPARgamma coactivator 1 alpha/PPARalpha-mediated transcription program; prevented SREBP1c-mediated lipogenesis in both liver and muscle by reducing fasting hyperinsulinemia; decreased hepatic cholesterol and cholesterol ester synthesis, reduced both VLDL-derived and endogenously synthesized fatty acid preventing muscle triglyceride accumulation; and improved overall insulin sensitivity and glucose tolerance.