Apocynin ameliorates endotoxin-induced acute lung injury in rats

Acute lung injury (ALI) is a serious clinical syndrome with a high rate of mortality. In this study, the effects of apocynin, a NADPH-oxidase (NOX) inhibitor on lipopolysaccharide (LPS)-induced ALI in rats were investigated. Male Sprague-Dawley rats were treated with apocynin (10 mg/kg) intraperitoneally (i.p.) 1 h before LPS injection (10 mg/kg, i.p.). The results revealed that apocynin attenuated LPS-induced ALI as it decreased total protein content, lactate dehydrogenase (LDH) activity and the accumulation of the inflammatory cells in the bronchoalveolar lavage fluid (BALF), In addition, apocynin significantly increased superoxide dismutase (SOD) and reduced glutathione (GSH) activities with significant decrease in the lung malondialdehyde (MDA) content as compared to LPS group in lung tissue and decreased pulmonary artery contraction induced by LPS. It also up regulated mRNA expression of inhibitory protein kappaB-alpha (NF kappa Bia) and downregulated mRNA expression of Toll-Like receptor 4 (TLR4) and decreased inflammation observed in lung tissues. Collectively, these results demonstrate the protective effects of apocynin against the LPS-induced ALI in rats through its antioxidant and antiinflammatory effect that may be attributed to the decrease in mRNA expression of TLR4 and increasing that of NF kappa Bia. (C) 2015 Elsevier B.V. All rights reserved.