Polaprezinc protects gastric mucosal cells from noxious agents through antioxidant properties in vitro

Background: Polaprezine has been shown to exert an anti-oxidant property in a tube experiment, protect gastric mucosa from experimental ulcerations in vivo, and accelerate the healing of gastric ulcer in humans. Aim: To examine a possible protective effect of polaprezinc on oxidant-medi ated injury in primary monolayer cultures of rat gastric fundic mucosa, Methods: Cytotoxicity was quantified by measuring Cr-51 release. Whether or not polaprezine exerts an antioxidant property was investigated by determi ning the effect of this agent on hydrogen peroxide (H2O2)-induced injury. T he effects of polaprezine on superoxide (O-2(-)) generation as well as on e thanol (EtOH)-induced injury were also examined, Generation of O-2(-) was a ssessed by the reduction in cytochrome c, Results: H2O2 caused a time- and dose-dependent increase in Cr-51 release, The dose-response curve of Cr-51 release by H2O2 Shifted to the right in th e presence of polaprezinc. Polaprezinc, at submillimolar concentrations, pr evented H2O2-induced Cr-51 release, EtOH also caused a dose-dependent incre ase in Cr-51 release, which was prevented by the addition of polaprezinc, T he incubation of cells with EtOH caused an increase in cytochrome c reducti on, as the concentrations of EtOH increased. Polaprezinc inhibited EtOH-ind uced cytochrome c reduction. Protection by polaprezine was microscopically associated with the prevention of monolayer disruption. Conclusions: Polaprezinc is antioxidative and directly protects gastric muc osal cells from noxious agents through its antioxidant properties in vitro. This finding may provide the theoretical basis for the usage of an antiulc er drug with antioxidant properties for the treatment of gastric inflammati on, such as that induced by ethanol.