Citrus flavanones alter the expression of genes involved in triglyceride metabolism in old age Wistar rats

Abstract

Advanced age is associated with development of dyslipidemia, together with ectopic triglycerides (Tg) accumulation in the liver. Consumption of citrus flavanones, naringenin (NAR) and hesperetin (HES) positively correlates with improvement of dyslipidemia in rats. However, information about this effects of citrus flavanones in old-aged rats still lack. Therefor we analyzed changes in gene expressions of liver X receptor (Lxr), thyroid hormone responsive spot14 protein (Thrsp), fatty acid synthase (Fas) and fatty acid translocase (Fat) in the liver by qPCR and serum Tg concentration biochemically. NAR or HES, suspended in vehicle (sunflower oil) were administrated orally (15 mg/kg) to male 24-month-old Wistar rats (n=5) during 4 weeks. Control groups received vehicle (CON) or stayed physiologically intact (ICON). In comparison to ICON animals, only Fat gene increased after sunflower oil administration. NAR and HES treatment decreased mRNA expression of Thrsp, Lxr and Fat genes in comparison to CON. Only NAR decreased Fas gene expression as well, while Tg concentration remained unchanged after both. All changes were statistically significant (p<0.05). In conclusion, nutritional doses of NAR or HES affect relative mRNA concentration of genes involved in control of Tg metabolism. Serum Tg did not change, but gene expression of Thrsp, Lxr and Fat was lower after both, while Fas was decreased only after NAR. This is of great importance because treatment with NAR or HES could protect liver from fatty acids and Tg de novo biosynthesis and ectopic lipid accumulation, thus preventing liver steatosis and dyslipidemia accompanied with advanced age.