Effects of policosanol on serum cholesterol levels in hyperlipidemia rats / 中国药理学与毒理学杂志

ABSTRACT

AIM To explore effects of policosanol on depressing cholesterol in hyperlipidemia rats and the correlated biochemistry mechanism. METHODS The rats were randomly divided into normal control, policosanol 4 mg·kg~(-1) prevention, hyperlipidemia model, policosanol 4, 6 and 8 mg·kg~(-1) and lovastatin positive control groups. The later 5 group rats were fed with high-cholesterol diets for 4 weeks in order to make hyperlipidemia model and beginning from the 5th week, in addition to the normal control and model groups, other groups were ig given policosanol or lovastatin once a day for 6 weeks, respectively, and policosanol protection group rats were ig given with policosanol 4 mg·kg~(-1) once a day for 10 weeks, together with high-cholesterol diets everyday. Total cholesterol(TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) concentrations in the serum and fecal bile acid (FBA) in the exrement were determined by auto-biochemistry analyzer. The activity of 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase in hepatocellular microsomes was detected by ultraviolet spectrophotometric analysis and activity of low density lipoprotein receptor (LDL-R) in peripheral blood lymphocyte was detected by fluorescence labelled integrator method. RESULTS Compared with hyperlipemia model group, the levels of TC decreased (39.1%-46.4%), LDL-C decreased (66.6%-80.7%), and FBA increased (9.7%-19.0%), the activity of HMG-CoA reductase decreased （13.8%-23.6%）, and activity of LDL-R increased (27.5%-129.6%) in policosanol prevention, policosanol 4, 6 and 8 mg·kg~(-1) and lovastatin groups, respectively; HDL-C increased （12.2%-16.7%） in policosanol prevention and policosanol 8 mg·kg~(-1) groups; TG decreased in lovastatin group. CONCLUSION Policosanol has significant effects on decreasing cholesterol. The decreasing cholesterol mechanism should include: ① increasing FBA excretion; ② decreasing the activity of HMG-CoA reductase; ③ increasing activity of LDL-R.