槲皮素对小鼠肺缺血再灌注损伤的保护作用及机制研究

Protective effect and mechanism of quercetin on acute lung injury induced by ischemia-reperfusion in mice

目的:探讨槲皮素对小鼠肺缺血再灌损伤(LIRI)的保护作用及可能的机制。方法:将40只C57BL/6雄性小鼠随机分为对照组、模型组、槲皮素低剂量(2.5 mg/kg)组、中剂量(5 mg/kg)组和高剂量(10 mg/kg)组,每组各8只。实验前5 d,槲皮素各剂量组小鼠灌胃给予相应剂量槲皮素,对照组和模型组小鼠灌胃给予等体积生理盐水;微血管钳闭塞左肺门肺血管建立LIRI小鼠模型;HE染色观察肺组织病理损伤;测量小鼠肺组织湿/干重比(W/D)值;酶联免疫吸附试验(ELISA)测量肺组织和血清中肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和白细胞介素-1β(IL-1β)含量;蛋白免疫印迹检测肺组织中PI3K-AKT-NFκB信号相关蛋白的表达量。结果:与模型组比较,槲皮素呈剂量依赖性缓解LIRI引起的肺泡壁水肿、肺间质增厚、肺泡结构破坏和肺泡腔内大量炎性细胞浸润等病理变化,降低肺损伤评分(P<0.05);ELISA结果显示,槲皮素呈剂量依赖性降低LIRI小鼠肺组织和血清中TNF-α、IL-6和IL-1β含量(P<0.05);蛋白免疫印迹结果显示,槲皮素呈剂量依赖性降低小鼠肺组织中p-p65/p65、p-IκBα、p-AKT/AKT和p-PI3K蛋白表达量(P<0.05)。结论:槲皮素能有效改善小鼠LIRI,机制可能与抑制PI3K-AKT-NFκB信号通路有关。

Objective:To study the protective effect of quercetin on acute lung injury(LIRI)induced by ischemia-reperfusion in mice.Methods:40 C57BL/6 male mice were randomly divided into control group,model group,low-dose quercetin(2.5 mg/kg)group,middle-dose(5 mg/kg)group and high-dose(10 mg/kg)group,8 cases in each group.5 days before the experiment,mice in each dose of quercetin group were given the corresponding concentration of quercetin by gavage,and the control group and the model group were given the same volume of normal saline by gavage.Mouse model of LIRI was established by occlusion of pulmonary vessels in the left hilum of lung with microvascular clamp.Hematoxylin-eosin staining was used to observe the pathological damage of lung tissue and score.The wet/dry weight ratio(W/D)value of mouse lung tissue was measured.Enzyme-linked immunosorbent assay(ELISA)was used to measure lung tissue and serum tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and interleukin-1β(IL-1β)content.Western blot was used to detect the expression of PI3K-AKT-NFκB signal protein in lung tissue.Results:Compared with the model group,quercetin relieved LIRI-induced alveolar wall edema,pulmonary interstitial thickening,alveolar structure destruction,and massive inflammatory cell infiltration in the alveolar cavity in a dose-dependent manner,and reduced lung injury score(P<0.05).ELISA results showed that quercetin decreased the levels of TNF-α,IL-6 and IL-1βin the lung tissue and serum of LIRI mice in a dose-dependent manner(P<0.05).Western blot results showed that quercetin decreased the expression of p-p65/p65,p-IκBα,p-AKT/AKT and p-PI3K in the lung tissue of mice in a dose-dependent manner(P<0.05).Conclusion:Quercetin improves acute lung injury induced by ischemia-reperfusion in mice,and the mechanism may be related to the inhibition of PI3K-AKT-NFκB signaling pathway.