Protective effects of quercetin in rats with lipopolysaccharide-induced acute lung injury

Objective To investigate the protective effects of quercet in rats with lipopolysaccharide-induced acute lung injury(ALI).Methods Lipoplysaccharidel(LPS,6 mg/kg,iv)reproduced the model of ALI in rats.24 SD rats were randomly divided into three groups(n=8)?Six hours after lipopolysaccharide or normal saline was administered by intravenous injection,the levels of tumour necrosis factor alpha(TNF-α),interleukin-8(IL-8)and P-selectin in serum were measured by radioimmunoassay and arterial blood gases were analysed.The rats were sacrificed by bleeding at the end of experiment,the pathological changes of rat lungs were observed,the wet and dry weight ratio(W/D)was calculated,the concentration of lung myeloperoxidase(MPO)was detected by the method of colorimetry.The levels of plasma TNF-α,IL-8 and P-selectin of lung tissue were measured by radioimmunoassay.Results In ALI model group,the levels of W/D,PaCO 2,MPO,TNF-α,IL-8,P-selectin were increased significantly(P0.01),whereas PaCO 2 and arterial pH were obviously decreased compared with control group(P0.01).Compared with ALI model group these changes were markedly attenuted in Quercetin pretreatment group (P0.05)and the pathological changes of the lung were also ameliorated.Conclusion Quercetin has a protective effect on LPS-induced acute lung injury in rats through inhibiting the inflammatory mediators,thus improving gas exchange ability.