Apoptosis initiated by carbon tetrachloride in mitochondria of rat primary cultured hepatocytes

Aim: To investigate the mitochondria-initiated apoptosis pathway involved in Carbon tetrachloride (CCl4) hepatotoxicity in vitro. Methods: Several cytotoxic-ity endpoints, including WST-8 metabolism, lactate dehydrogenase leakage and morphological changes, were examined. The 5,5’-dithio-bis(2-nitrobenzoic acid) reaction was used to measure reduced glutathione level, and the malondialdehyde level was determined using the thiobarbituric acid assay. The release of cyto-chrome c and Bcl-XLwas detected by Western blot. Caspase-3 activity was mea sured using the fluorogenic substrate Ac-DEVD-AMC. DNA fragmentation wasused to evaluate cell apoptosis. Results: A time-and dose-dependent decrease in cellular glutathione content was observed, along with a concomitant increase in malondialdehyde levels following the application of CCl4. Caspase 3 activity was stimulated at all doses of CCl4, with the most significant activation at 3 mmol/L. Cytochrome c was released obviously after CCl4treatment. A time-dependent decrease in BcI-XLexpression was observed. DNA fragmentation results revealed apoptosis and necrosis following CCl4treatment. Conclusion: Oxidative damage is one of the essential mechanisms of CCl4hepatotoxicity, which triggers apoptosis via the mitochondria-initiated pathway.