Phellinu merrillii (PM)，is a traditional medicinal plant of oriental people (especially in China, Japan and North Korea ), was demonstrated to exhibit anti-bacterial, antitumour, antifibrotic, antioxidant and anti-inflammatory functions in several studies. Moreover, it has the best anticancer activity in higher fungi as we have already known. Hispolon is a major component of (PM) with great antioxidant activity. And Hispolon had been reported to present apoptotic effect on human epidermoid KB cells, but the exact molecular mechanism of Hispolon on cell death from acute promyelocytic leukemia cell, NB4, is still not clear. Here we investigate it that Hispolon induced cytotoxicity, DNA damage and fragmentation, cell cycle arrest, and apoptosis on NB4 cell.
In this study, the dye exclusion (trypan blue) indicated that Hispolon induced cytotoxicity in a time- dependent and dose-dependent manner. Hispolon induced DNA damage and fragmentation was confirmed by DAPI staining and DNA laddering assay. The results demonstrated that Hispolon increased the apoptosis related protein level of caspase 3、8、9 and Bax, and decreased Bcl-2 and Bid. It also promoted the level of cell cycle related proteins such as p53 and p21, and inhibited the expression the levels of cyclin D1、cyclin E、Cdk 2 and Cdk 4. These results suggested that Hispolon inhibited the cell growth, induced apoptosis and might be valuable for therapeutic leukemia disease.
