Effects of thiol on NF-kB activity in and release of TNF-a from endotoxin-activated cultured rat kupffer cells

Objective To determine whether thiol can affect the activity of nuclear factor kappa B （NF-kB ） in and release of TNF-afrom lipopolysaccharide （LPS） -activated kupffer cells （KCs） and ascertain whether these effects are mediated through glutathione （GSH）. Methods KCs were isolated from livers of healthy male adult SD rats weighing 250-300g and cultured for 12h. The cultured KCs were exposed to LPS 10 ng·ml^-1 . The effects of different concentrations of glutathione monoethylester （GSHEE） and N-acetylcysteine （NAC） on NF-kB activity in and release of TNF-afrom KCs were determined. The effect of pretreatment with GSH synthesis inhibitor - BSO on the inhibitory effect of NAC on inflammation was investigated. NFkB activity was determined by electrophoretic mobility shift assay （EMSA） and intracellular GSH content and TNF-alevel in supernatant by HPLC. Results Intracellular GSH content remained unchanged after exposure of KCs to LPS. Both GSHEE and NAC increased intracellular GSH level and inhibited NF-kB activity and release of TNF-a. BSO blocked the increase in GSH induced by NAC but did not affect the inhibitory effect of NAC on TNF-urelease. Conclusions LPS does not affect GSH level in KCs. NAC can inhibit NF-kB activity in and TNF-urelease from KCs and increase intracellular GSH level but the inhibitory effect is not mediated through GSH. Key words: Thiol;  Endotoxin;  Kupffer cells;  NF-kappa B