Molecular mechanism of Chuanxiong Rhizoma in treating coronary artery diseases

Abstract 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 (NO3−-NO2−-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 NO3−, NO2− and NO levels were examined in the NO3−-NO2−-NO pathway. High-performance ion chromatography was used to quantify NO3− and NO2− 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 NO3− and low content of NO2− was found in CR, and which could potently convert NO3− to NO2− in the presence of endogenous reductase enzyme. Incubating human coronary artery endothelial cells (HCAECs) with CR-containing serum showed that CR significantly decreased the NO3− content and increased the levels of NO2− 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 NO3−-NO2−-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.