Background:Lipid-lowering effect ofRhus coriaria L.(Rhus) has been investigated in multiple animal studies with promising results.Nonetheless,its clinical efficacy has not been adequately examined.Objective:The aim of this study was to evaluate the lipid-lowering effects of Rhus among patients with hyperlipidemia.Design,setting,participants and interventions:The study was designed as a two-arm,double-blind placebo-controlled randomized clinical trial,using a parallel design.Eighty patients with primary hyperlipidemia were randomly assigned to receive Rhus capsules or placebo for 6 weeks.Main outcome measures:The serum lipid levels,apolipoprotein-A1 (Apo-A1) and apolipoprotein-B (Apo-B) were measured.Results:Mean serum high-density lipoprotein cholesterol (HDL-C) and Apo-A1 levels were significantly increased in the Rhus group,compared with the placebo group,after 6weeks of intervention (P =0.001).The analysis of covariance test including age,gender,body mass index (BMI),and smoking as co-variables revealed that the increase in HDL-C and Apo-A1 levels remained significant,and increases in HDL-C were dependent on the increase in Apo-A1 levels.No significant difference was observed between Rhus and placebo groups in terms of mean reductions in total cholesterol,low-density lipoprotein cholesterol and triglyceride levels;however,more significant improvement was observed among obese patients (BMI ＞ 30 kg/m2).Conclusion:The study showed significant increases in HDL-C and Apo-A1 levels in response to Rhus supplementation in patients with hyperlipidemia.