The Effect of α-Lipoic Acid on Mitochondrial Respiratory Rate and Energy Metabolism in Hepatoma Cells in Response to Hypoxia Stress
α-硫辛酸对缺氧应激肝癌细胞线粒体呼吸率和产能代谢的影响

This study investigated the ability of the antioxidant, alpha-lipoic acid, to scavenge the reactive oxygen species (ROS) in hepatoma cells, and assessed how the effects of alpha-lipoic acid on cell proliferation differed between SMMC-7721 human hepatoma cells and L02 immortalized normal liver cells. The effect of the antioxidant on cell survival ratio, mitochondrial activity and energy metabolism was explored further under the condition of hypoxia. Effects of the antioxidant for cancer cells and normal cells were compared to see if they differed. Cell growth and the level of ROS in cells were analysed in response to different concentrations of alpha-lipoic acid treatment. The survival ratio, ROS level in cells, consumption of O2, generation of ATP and mRNA levels of c-myc ongogene were each detected under hypoxic condition, respectively in response to 5 mmol/L alpha-lipoic acid. The results suggest that hepatoma cells compensatively increase ATP generation though increasing the glycolysis pathway in response to hypoxia, the antioxidant, alpha-lipoic acid, scavenge the excess ROS in cells and decrease the mitochondria respiratory rate in hepatoma cells, and alpha-lipoic acid inhibit the proliferation of hepatoma cells and decrease their ability to endure hypoxia by downregulating the expression of c-myc.