Pyrogallol induces the death of human pulmonary fibroblast cells through ROS increase and GSH depletion

Pyrogallol (PG) inhibits the growth of various cells via stimulating O2 -mediated death. This study investigated the effects of PG on cell death in human pulmonary fibroblast (HPF) cells in relation to reactive oxygen species (ROS) and glutathione (GSH) levels. PG inhibited the growth of HPF cells with an IC50 of ~50-100 M at 24 h. PG induced a G1 phase arrest of the cell cycle and also triggered cell death accompanied by the loss of mitochondrial membrane potential (MMP; m), Bcl-2 decrease, p53 increase and the activation of caspase-3. PG increased O2 - level in HPF cells and depleted GSH content in these cells. Z-VAD (a pan-caspase inhibitor) did not significantly change cell growth inhibition, death and MMP (m) loss in PG-treated HPF cells. N-acetylcysteine (NAC) attenuated growth inhibition, death and MMP (m) loss in PG-treated HPF cells and it decreased O2 - level in these cells as well. However, L-buthionine sulfoximine (BSO) strongly increased ROS level in PG-treated HPF cells and it intensified growth inhibition, cell death, MMP (m) loss and GSH depletion in these cells. In conclusion, PG-induced HPF cell death was closely related to increases in ROS level and GSH depletion.