Estrogen is involved in lipid metabolism. Menopausal women with low estrogen secretion usually gain weight and develop steatosis associated with abnormal lipid metabolism. A previous study showed that blackcurrant (Ribes nigrum L.) extract (BCE) had phytoestrogen activity. In this study, we examined whether BCE improved lipid metabolism abnormalities and reduced liver steatosis in ovariectomized rats, as a menopausal animal model. Twelve-week-old ovariectomized (OVX) rats were fed a regular diet (Ctrl) or a 3% BCE supplemented diet while sham rats were fed a regular diet for three months. Body weight, visceral fat weight, levels of serum triglycerides, total cholesterol, and LDL cholesterol decreased in the BCE-treated OVX and sham rats, but not in OVX Ctrl rats. The results of hematoxylin and eosin staining revealed that BCE decreased the diameters of adipocytes and the nonalcoholic fatty liver disease activity score. Furthermore, quantitative RTPCR indicated a decreased expression of hepatitis-related genes, such as tumor necrosis factor-α, IL-6, and IL-1β in OVX rats after BCE treatment. This is the first study that reported improvement of lipid metabolism abnormalities in OVX rats by BCE administration. These results suggest that the intake of BCE alleviated dyslipidemia and prevented nonalcoholic steatohepatitis during menopause in this animal model.
Keywords: blackcurrant; dyslipidemia; liver steatosis; ovariectomized; phytoestrogen.