s-Ethyl Cysteine and s-Methyl Cysteine Post-intake Attenuated LPS-induced Lung Injury in Mice

Abstract

Objective: Effects of s-ethyl cysteine (SEC) and s-methyl cysteine (SMC) upon lipopolysaccharide (LPS)-induced acute lung injury in mice were examined. Materials and Methods: The acute lung injury was induced by intranasal injecting LPS, 10 mg in 50 ml phosphate buffer saline. Eight hours after LPS challenge, SEC or SMC was supplied in drinking water at 0.5 or 1% for 3 days. Blood and lung were collected. Lung wet/dry weight ratio, myeloperoxidase activity, and lung level of oxidative and inflammatory factors were measured. Western blot analyses were used to determine the protein expression of associated factors. Results: LPS increased lung myeloperoxidase activity, neutrophil counts and edema. SEC or SMC post-intake attenuated these events. SEC or SMC treatments limited LPS-induced lung expression of nuclear factor-κB, p-p38, NADPH oxidase and Bax, and decreased the production of tumor necrosis factor-alpha, monocyte chemoattractant protein-1, prostaglandin E2 and reactive oxygen species in lung. Conclusions: These findings suggest that SEC or SMC could protect lung through their anti-inflammatory, anti-oxidative and anti-apoptotic activities.