Propyl gallate inhibits the growth of HeLa cells via regulating intracellular GSH level

Propyl gallate (PG) as a synthetic antioxidant exerts a variety of effects on tissue and cells. Here, we investigated an involvement of glutathione (GSH) and reactive oxygen species (ROS) in PG-induced inhibition of HeLa cell growth. PG dose-dependently inhibited HeLa cell growth and induced apoptosis at 24 h. The intracellular ROS levels including O2- were increased or decreased in PG-treated HeLa cells depending on the incubation times (1 or 24 h) and doses (100–1600 μM). PG increased activities of superoxide dismutase (SOD) and catalase in HeLa cells. PG significantly increased GSH depleted cells in a time- and dose-dependent manner. Treatment with 2 mM N-acetyl-cysteine (NAC; a well known antioxidant) slightly prevented 400 μM PG-induced cell death, which was accompanied by an increase in ROS level and a decrease in GSH depletion level. PG induced a G1 phase arrest of the cell cycle. NAC did not affect the cell cycle distributions in PG treated- or untreated-HeLa cells. Conclusively, PG inhibited the growth of HeLa cells via regulating GSH level rather than ROS level. Our present data could provide useful information on the molecular anti-growth mechanisms of PG in cancer cells in relation to ROS and GSH level.