cytochrome-c-t and didymin

In the present study, a flavonoid was isolated from Origanum vulgare and identified as didymin. The effect and mechanism of O. vulgare didymin (OVD) on human HepG2 liver carcinoma cell was then assessed. Our results showed that OVD strongly inhibited the viability, clonogenicity and migration of HepG2 cells. OVD significantly induced apoptosis and induced cell cycle arrest at G2/M phase by regulating cyclin B1, cyclin D1 and CDK4. The anti-proliferative and pro-apoptotic effects were associated with changes in the Bcl-2/Bax ratio and induction of caspase-mediated apoptosis. Moreover, OVD attenuated the mitochondrial membrane potential, accompanied by the release of cytochrome c. In addition, OVD inhibited the ERK/MAPK and PI3K/Akt pathways by increasing the level of Raf kinase inhibitor protein (RKIP). Our study indicates that OVD induces apoptosis against of HepG2 cells through mitochondrial dysfunction and inactivation of the ERK/MAPK and PI3K/Akt pathways by up-regulating RKIP.

Topics: Apoptosis; Carcinoma, Hepatocellular; Caspase 3; Caspase 9; Cell Cycle; Cell Cycle Proteins; Cell Movement; Cell Survival; Clone Cells; Cytochromes c; Flavonoids; Glycosides; Hep G2 Cells; Humans; Liver Neoplasms; MAP Kinase Signaling System; Membrane Potential, Mitochondrial; Mitochondria; Phosphatidylethanolamine Binding Protein; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Up-Regulation

Didymin has been reported to have anti-cancer potential. However, the effect of didymin on liver fibrosis remains illdefined.. Hepatic fibrosis was induced by CCl4 in rats. The effects of didymin on liver pathology and collagen accumulation were observed by hematoxylin-eosin and Masson's trichrome staining, respectively. Serum transaminases activities and collagen-related indicators levels were determined by commercially available kits. Moreover, the effects of didymin on hepatic stellate cell apoptosis and cell cycle were analyzed by flow cytometry. Mitochondrial membrane potential was detected by using rhodamine-123 dye. The expression of Raf kinase inhibitor protein (RKIP) and the phosphorylation of the ERK/MAPK and PI3K/Akt pathways were assessed by Western blot.. Didymin significantly ameliorated chronic liver injury and collagen deposition. It strongly inhibited hepatic stellate cells proliferation, induced apoptosis and caused cell cycle arrest in G2/M phase. Moreover, didymin notably attenuated mitochondrial membrane potential, accompanied by release of cytochrome C. Didymin significantly inhibited the ERK/MAPK and PI3K/Akt pathways. The effects of didymin on the collagen accumulation in rats and on the biological behaviors of hepatic stellate cells were largely abolished by the specific RKIP inhibitor locostatin.. Didymin alleviates hepatic fibrosis by inhibiting ERK/MAPK and PI3K/Akt pathways via regulation of RKIP expression.

Topics: Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; Caspases; Cell Cycle; Cell Cycle Proteins; Cell Proliferation; Collagen; Cytochromes c; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Glycosides; Liver; Liver Cirrhosis; Male; Membrane Potential, Mitochondrial; Mitochondria; Phosphatidylethanolamine Binding Protein; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats, Sprague-Dawley; Signal Transduction; Tumor Necrosis Factor-alpha