The effects of the extracts from Carthamus tinctorius L. on gene expression related to cholesterol metabolism in rats

Carthamus tinctorius L. (safflower) is in Thailand traditionally used for a herbal tea for health to reduce cholesterol and prevent atherosclerosis. The present study was aimed to investigate the effect of the crude extracts from safflower on cholesterol metabolism in high cholesterol fed rats. The crude extract was fractionated in hexane, dichloromethane, and methanol. To evaluate the hypolipidemic effect, the safflower extracts were daily fed to normal and hyperlipidemic rats induced by 2%-cholesterol diet (W/W) supplementation, at dose of 250 mg/kg body wt. During the 4-week study, body weight, food intake, organ weight, and plasma cholesterol levels were evaluated. Animals treated with 2%-cholesterol diet and dichloromethane fraction for a week exhibited decreased body weight. After treatment for 14 and 30 days, a significant reduction in total cholesterol and total cholesterol/HDL-cholesterol and a significant induction in HDL-cholesterol were observed in the hypercholesterolemic rats treated with the dichloromethane extract. Higher expression of SRBI and ABCA1 in the liver of the control group was observed after 4 weeks whereas no significant difference in the expression level of SRBI and ABCA1 was found in groups treated with extract after 2 and 4 weeks. The results of this study suggested that the dichloromethane extract can reduce the total cholesterol/HDL-cholesterol of hyperlipidemic rats. The expression of SRBI and ABCA1 mRNA may not be regulated by the crude extract of safflower, which may not in part explain the decrease in HDL-cholesterol and gene encoding enzymes of the cholesterol biosynthetic pathway.