Effects of BisGMA on glutathione metabolism and apoptosis in human gingival fibroblasts in vitro

Abstract

Aim of this study was to investigate the effects of the resin monomer BisGMA on the glutathione concentration (monobromobimane assay) and apoptosis (Annexin V/PI-assay) of cultured primary human gingival fibroblasts. Cells were treated for up to 24h with 0.001-0.25 mM BisGMA to determine growth curves using the DNA stain H33342. Subsequent Annexin V/PI-assays revealed that fibroblasts exposed to concentrations of 0.005-0.01 mM (non-cytotoxic) and 0.05 mM (ED(10)-concentration) showed no increase of the share of apoptotic cells compared to non-treated controls (5-8%), while 0.1 mM BisGMA (approximately ED(50)-concentration) caused a significant increase of the percentage of apoptotic cells (50%). Simultaneously to the induction of apoptosis, 0.1 and 0.25 mM of BisGMA caused a significant depletion of the intracellular GSH content after 18 h of incubation. Our results indicate that BisGMA at concentrations >0.1 mM causes an extreme depletion of the intracellular GSH pool as well as apoptosis.