Hyperlipidemia is a multifaceted
metabolic disease, which is the major risk factor for
atherosclerosis and
cardiovascular diseases.
Traditional Chinese medicine provides valuable therapeutic strategies in the treatment of
hyperlipidemia. Inonotus obliquus has been used in
traditional medicine to treat numerous diseases for a long time. To screen and isolate the fractions of I. obliquus
polysaccharides (IOP) that can reduce blood
lipid in the
hyperlipemia animals and cell models, and investigate its mechanisms. The active component IOP-A2 was isolated, purified, and identified. In vivo, rats were randomly divided into blank control group (NG), the high-fat treatment group (MG),
lovastatin group (PG), and IOP-A group. Compared with MG, the hyperlipidemic rats treated with IOP-A2 had decreased
body weight and organ indexes, with the level of serum total
cholesterol (TC),
triglyceride (TG), and
low-density lipoprotein cholesterol (
LDL-C) significantly decreased (p < .05), and level of serum
high-density lipoprotein cholesterol (HDL-C) significantly increased (p < .05). Hepatocyte steatosis in hepatic lobules was significantly reduced. In vitro, the accumulation of lipid droplets in the model of fatty degeneration of HepG2 cells was significantly alleviated, and cellular TC and TG content was significantly decreased (p < .01). Moreover, the expression of recombinant
cytochrome P450 7A1 (CYP7A1) and
Liver X Receptor α (LXRα) were up-regulated (p < .05) both in vivo and in vitro. The results showed that IOP-A2 may exert its hypolipidemic activity by promoting
cholesterol metabolism and regulating the expression of the
cholesterol metabolism-related
proteins CYP7A1, LXRα, SR-B1, and ABCA1.