Objective:To investigate the short- and long-term effects of Xuezhikang(血脂康,XZK),an extract of Cholestin,on proprotein convertase subtilisin/kexin type 9(PCSK9) level.Methods:Thirty rats were randomly divided into three groups and were given saline,XZK 1,200 mg/kg or lovastatin 10 mg/kg respectively by daily gavage for 3 days(n=10 for each).Sixteen patients without previous iipid-lowering drug treatment for dyslipidemia received XZK 1,200 mg daily for 8 weeks.Fasting blood samples and liver tissue were collected at day 3 for rats,while the blood samples were obtained at baseline and week 8 from patients.The serum PCSK9 and lipid profile were measured.The expression of hepatic low density lipoprotein(LDL) receptor and sterol regulatory element binding protein 2(SREBP-2) were measured by real time-PCR.Results:PCSK9 levels in rats were significantly increased in the XZK and lovastatin groups(P=0.002,P=0.003 vs.control) at day 3,while no significant differences were found in the levels of lipid parameters.PCSK9 levels in patients increased by34%(P=0.006 vs.baseline) accompanied by total cholesterol and LDL-cholesterol decreased by 22%and 28%(P=0.001,P=0.002 vs.baseline).The hepatic mRNA levels of LDL-receptor and SREBP-2 were significantly increased in the XZK and lovastatin groups.Conclusion:XZK has significant impact on PCSK9 in a short- and long-term manner in both rats and humans.Moreover,the data indicated that as lovastatin,XZK increased PCSK9 levels through SREBP-2 pathway. Objective: To investigate the short- and long-term effects of Xuezhikang (XZK), an extract of Cholestin, on proprotein convertase subtilisin / kexin type 9 (PCSK9) level. Methods: Thirty rats were randomly divided into three groups and were given saline, XZK 1,200 mg / kg or lovastatin 10 mg / kg respectively by daily gavage for 3 days (n = 10 for each). Sixteen patients without previous iipid-lowering drug treatment for dyslipidemia received XZK 1,200 mg daily for 8 weeks. Fasting blood samples and liver tissue were collected at day 3 for rats, while the blood samples were obtained at baseline and week 8 from patients. Serum PCSK9 and lipid profile were measured. The expression of hepatic low density lipoprotein (LDL) receptor and sterol Results: PCSK9 levels in rats were significantly increased in the XZK and lovastatin groups (P = 0.002, P = 0.003 vs. control) at day 3, while no significant differences were found in the leve ls of lipid parameters. PCK9 levels in patients increased by 34% (P = 0.006 vs.baseline) accompanied by total cholesterol and LDL-cholesterol decreased by 22% and 28% (P = 0.001, P = 0.002 vs.baseline) mRNA levels of LDL-receptor and SREBP-2 were significantly increased in the XZK and lovastatin groups. Confc: XZK has significant impact on PCSK9 in a short- and long-term manner in both rats and humans. More over, the data indicated that as lovastatin, XZK increased PCSK9 levels through SREBP-2 pathway.