Molecular mechanism of Chuanxiong Rhizoma in treating coronary artery diseases

OBJECTIVE: Most of the studies on the herb Chuanxiong Rhizoma (CR) have focused on the l-arginine-nitric oxide (NO) pathway, but the nitrate-nitrite-NO (NO(3)(−)–NO(2)(−)–NO) pathway was rarely investigated. Therefore, the aim of this study was to evaluate the effects and mechanisms of action of CR in coronary artery disease (CAD). METHODS: The NO(3)(−), NO(2)(−) and NO levels were examined in the NO(3)(−)–NO(2)(−)–NO pathway. High-performance ion chromatography was used to quantify NO(3)(−) and NO(2)(−) levels. Then, NO was quantified using a multifunctional enzyme marker with a fluorescent probe. The tension of aortic rings was measured using a multi myograph system. RESULTS: High content of NO(3)(−) and low content of NO(2)(−) was found in CR, and which could potently convert NO(3)(−) to NO(2)(−) in the presence of endogenous reductase enzyme. Incubating human coronary artery endothelial cells (HCAECs) with CR-containing serum showed that CR significantly decreased the NO(3)(−) content and increased the levels of NO(2)(−) and NO in the cells under hypoxic conditions. In addition, CR significantly relaxed isolated aortic rings when the l-arginine –NO pathway was blocked. The optimal concentration of CR for relaxation was 200 mg/mL. CONCLUSION: CR supplements large amounts of NO in cells and vessels to achieve relaxation via the NO(3)(−)–NO(2)(−)–NO pathway, thereby making up for the deficiency caused by the lack of NO after the l-arginine-NO pathway is suppressed. This study also supports the potential use of a traditional Chinese herb for future drug development.