Molecular mechanism of Graptopetalum paraguayense E. Walther extracts induced growth inhibition and apoptosis in humam malignant melanoma A375. S2 cell lines

• Main Authors: Yu-Feng Lin, 林鈺鳳
• Other Authors: Su-Tze Chou
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/623drh

碩士 === 靜宜大學 === 食品營養研究所 === 94 === Recently, there is increasing interest in finding natural antioxidant from plants to protect human body against cancer. Carcinoma is the major death cause in Taiwan. Graptopetalum paraguayense E. Walther is a traditional Chinese herbal medicine. Our in-vitro study had showed that Graptopetalum paraguayense E. Walther (GP) extracts had antioxidant,antimutagenic,and tyrosinase inhibitory activities. In this study, we will examine the effects of 50% ethanolic extract from GP (GE50) on the growth of human malignant cell lines (A375. S2). The results demonstrated that GE50 can inhibit the cell growth, induce cell cycle arrest on G2/M phase. The morphology, DAPI staining and DNA fragmenation assay were conducted and they indicated that GE50 induced A375. S2 cells apoptosis. Western boltting analysis, GE50 decrease the protein level of cyclin A、cyclin B、cdc2 and cdc25c, and increased the level of CHK1、CHK2、Wee1、p53 and p21 of cells. Flow cytometry assay demonstrated that GE50 induced the change of mitochondria membrance potential and calcium concentration. In ER (endoplasmic reticulum) stress, GE50 can increase the expression of GRP-78 and GADD153. GE50 inhibited the expression of Bcl-2 and promoted the level of Bax. Furthermore, GE50 can increase the expression of cytochrome c、 caspase-9、caspase-3 and caspase-7. GE50 also can inhibit the invasiveness of human malignant cells by suppressing MMP-2 and MMP-9 expression. GE50 can increase superoxide dismutase and decreased the catalase、glutathion peroxidase activity and glutathion levels, however, GE50 increased malondialdehyde levels in A375. S2 cells. The results of this study we suggested that GE50 might inhibite cell growth and induced G2/M phase arrest. GE50 induced apoptosis throught the activation of p53、Bax , induced calcium concentration, which lead to change on mitochondria membrance permeability and release of cytochrome c. Therefore, caspase-9、caspase-3、caspase-7 、GRP-78 and GADD153 are activited and decrease MMP-2 and MMP-9 expression. Furthermore, our results demonstrate that GE50 can change GSH antioxidant system. The current evidence suggests that Graptopetalum paraguayense E. Walther can inhibite the cell growth, induce apoptosis and inhibit invasiveness.