Polysaccharide extracts of Cirsium japonicum protect rat H9c2 myocardial cells from oxidative stress induced by hydrogen peroxide

Daji (Cirsium japonicum) has been applied against gastric disorders, lung diseases, and cardiovascular problems in the traditional Chinese medicinal system. The present study was to investigate the protective effects of Daji (Cirsium japonicum) polysaccharide extracts (CJP) against hydrogen peroxide (H2O2) shock in rat H9c2 myocardial cells. First, CJP was isolated by hot water extraction and ethanol precipitation; it was then characterized by high performance liquid chromatography and infrared spectrum analysis. Rat H9c2 cells were subjected to H2O2 treatment to establish a cell injury model. The 3(4,5dimethylthiazol2yl)2,5diphenyltetrazolium bromide assay showed that CJP pretreatment significantly ameliorated the H2O2 injury in a dosedependent manner. Furthermore, the cell apoptosis induced by H2O2 was markedly inhibited by CJP pretreatment, whereas the cleavage level of caspase3, 8, and 9 was reduced. In addition, the p38 mitogenactivated protein kinase pathway might be involved in the protective effect of CJP on myocardial cells. Therefore, we conclude that polysaccharide extracts of Daji (Cirsium japonicum) protect rat H9c2 myocardial cells from oxidative stress induced by H2O2.