Chinese medicine tongxinluo significantly lowers serum lipid levels and stabilizes vulnerable plaques in a rabbit model

Relevance to ethnopharmacology: Tongxinluo capsule is a compound preparation formulated on the basis of the meridian theory of traditional Chinese medicine and is officially approved for the treatment of angina pectoris and ischemic stroke in China. Objectives: To test the hypothesis that the Chinese traditional medicine tongxinluo in capsule form has similar effects as simvastatin in lowering serum lipid levels and stabilizing vulnerable plaques. Materials and methods: Thirty New Zealand white rabbits underwent balloon-induced abdominal aortic endothelial injury and were fed a diet of 1% cholesterol for 8 weeks. The rabbits were then randomly divided into three groups (n = 10 each) for daily doses of tongxinluo capsule (I g/kg), simvastatin(5 mg/kg) or no drugs for 12 weeks. At the end of week 20, plaque rupture was induced by pharmacological triggering. Serological, ultrasonographic, pathologic, immunohistochemical, and gene expression studies were performed. Results: The incidence of plaque rupture with tongxinluo and simvastatin treatment was significantly lower than that with control treatment (0% for both drug treatments vs. 56.0%; P<0.05). Values of serum lipid profile, inflammatory markers, and pathological and immunohistological assays were significantly improved in the tongxinluo- and simvastatin-treated groups than in the control group. The simvastatin-treated group showed lower serum lipid levels than the tongxinluo-treated group. Conclusions: Treatment with the Chinese medicine tongxinluo was as effective as simvastatin in lowering serum lipid levels, inhibiting plaque inflammation and preventing vulnerable plaques from rupture and may provide an alternative therapy for atherosclerosis. (C) 2009 Elsevier Ireland Ltd. All rights reserved.