[Epicatechin abolished TDCA-induced apoptosis in Huh7 cell by inhibiting Bax, p38 MAPK and ROS production].
OBJECTIVE
To investigate the molecular mechanisms involved in anti-apoptotic effects of epicathechin in liver cells.


METHODS
Human hepatoma cell line (Huh7) was treated with 400 miromol x L(-1) taurodeoxycholic acid (TDCA) for 48 hours to induce apoptosis. Intracellular generation of reactive oxygen species (ROS) was detected with DCFH-DA assay. Caspase-3/7 activity was analyzed with EnzoLyte Homogeneous AMC kit. Cell proliferation was measured by MTT assay. The expression of Bax, Phospho-p38 MAPK and the levels of cytochrome C were assessed by Western-blot analysis.


RESULTS
TDCA-dependent intracellular ROS production was 8-fold higher as compared to untreated cells, consequently resulting in 45% reduction of cell viability. Interestingly, pretreatment of cells with epicatechin resulted in a dose-dependent inhibition of TDCA-induced ROS generation and reduced cell apoptosis by threefold as compared to TDCA treatment alone. In addition epicatechin reduced Bax expression with consequential inhibition of cytochrome C release from mitochondria, inhibition of caspase 3/7 activation and p38 MAPK phosphorylation.


CONCLUSIONS
Epicatechin protects Huh7 cells from oxidative stress and mitochondria-induced apoptosis. The molecular mechanisms of anti-apoptotic effects of epicatechin were associated with inhibition of p38 MAPK phosphorylation and Bax expression, and reduction of ROS production. These findings implicate epicathechin might have potential as protective agent against a variety of oxidative stress-mediated liver conditions.
Yu
Jing
J
Hepatology Department, the First Affiliated Hospital of Guangxi Chinese Medical University, Nanning 530023, China. jingy1237@126.com
Khaoustov
Vladimir
V
Xu
Yumin
Y
Yoffe
Boris
B
D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D002392:Catechin / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D045304:Cytochromes c / Q000037:antagonists & inhibitors; D004347:Drug Interactions; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013657:Taurodeoxycholic Acid / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D051028:bcl-2-Associated X Protein / Q000037:antagonists & inhibitors*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
D011518:Proto-Oncogene Proteins; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D013657:Taurodeoxycholic Acid; D002392:Catechin; D045304:Cytochromes c; D048051:p38 Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; C069937:MAP3K8 protein, human