金丝桃甙对百草枯诱导的大鼠急性肺损伤的保护作用

Protective effect of hyperoside on paraquat-induced acute lung injury in rats

目的探究金丝桃甙(HYP)对百草枯(PQ)诱导的大鼠急性肺损伤的保护作用及其机制。方法将大鼠随机分为对照组、PQ组、低剂量金丝桃甙组(HYP-L组)、中剂量金丝桃甙组(HYP-M组)和高剂量金丝桃甙组(HYP-H组),每组12只。给予相应处理7 d后,检测各组大鼠支气管肺泡灌洗液(BALF)中的白细胞介素(IL)-1β、IL-6和巨噬细胞炎性蛋白-2(MIP-2)水平,以及肺组织中的丙二醛(MDA)和超氧化物歧化酶(SOD)水平。通过苏木精-伊红(HE)染色和Masson三色染色评估大鼠肺损伤和纤维化程度。通过Western blot检测肺组织中E-cadherin、α平滑肌肌动蛋白(α-SMA)、Vimentin及核因子红细胞2相关因子2(Nrf2)、核因子-κB(NF-κB)p65、p-NF-κB p65、转化生长因子-β1(TGF-β1)、Smad3和p-Smad3蛋白的表达水平。结果与对照组比较,PQ组大鼠BALF中的IL-1β、IL-6和MIP-2水平升高(P<0.05),肺组织中SOD水平降低(P<0.05),而MDA水平升高(P<0.05),肺组织出现明显损伤和纤维化(P<0.05)。与PQ组比较,HYP-L组、HYP-M组和HYP-H组大鼠BALF中的IL-1β、IL-6和MIP-2水平降低(P<0.05),肺组织中SOD水平升高(P<0.05),而MDA水平降低(P<0.05),肺组织损伤减轻,纤维化评分降低(P<0.05)。与对照组比较,PQ组大鼠肺组织中E-cadherin的表达水平降低(P<0.05),α-SMA和Vimentin的表达水平升高(P<0.05),Nrf2的蛋白表达水平降低(P<0.05),TGF-β1的蛋白表达水平以及NF-κB p65和Smad3蛋白的磷酸化水平均升高(P<0.05)。与PQ组比较,HYP-L组、HYP-M组和HYP-H组大鼠肺组织中E-cadherin的表达水平升高(P<0.05),α-SMA和Vimentin的表达水平降低(P<0.05),Nrf2的蛋白表达水平升高(P<0.05),TGF-β1的蛋白表达水平以及NF-κB p65和Smad3蛋白的磷酸化水平降低(P<0.05)。结论金丝桃甙有效减轻了百草枯诱导的大鼠急性肺损伤,其可能通过调节Nrf2、NF-κB和TGF-β1/Smad2/3信号通路减轻肺部氧化应激、炎症和纤维化。

Objective To investigate the protective effect and mechanism of hyperoside(HYP)on paraquat(PQ)-induced acute lung injury in rats.Methods Rats were randomly divided into the control group,the PQ group,the low-dose hyperoside group(HYP-L group),the middle-dose hyperoside group(HYP-M group)and the high-dose hyperoside group(HYP-H group),with 12 rats in each group.After 7 days of corresponding treatment,the levels of interleukin(IL)-1β,IL-6 and macrophage inflammatory protein-2(MIP-2)in bronchoalveolar lavage fluid(BALF)of rats in each group,as well as the levels of malondialdehyde(MDA)and superoxide dismutase(SOD)in lung tissue were detected.The degree of lung injury and fibrosis of rats were evaluated by hematoxylin-eosin(HE)staining and Masson's trichrome staining.The expression levels of E-cadherin,α-smooth muscle actin(α-SMA),Vimentin,and protein expression levels of nuclear factor erythroid 2-related factor 2(Nrf2),nuclear factor-κB(NF-κB)p65,p-NF-κB p65,transforming growth factor-β1(TGF-β1),Smad3 and p-Smad3 in lung tissue were detected by Western blot.Results Compared with the control group,the levels of IL-1β,IL-6 and MIP-2 in BALF of rats in the PQ group increased(P<0.05),the level of SOD in the lung tissue decreased,while the level of MDA increased(P<0.05),and the lung tissue showed obvious damage and fibrosis(P<0.05).Compared with the PQ group,the levels of IL-1β,IL-6 and MIP-2 in BALF of rats in the HYP-L group,the HYP-M group and the HYP-H group decreased(P<0.05),the levels of SOD in the lung tissue increased(P<0.05),while the levels of MDA decreased(P<0.05),and the lung tissue damages were alleviated,and the fibrosis score decreased(P<0.05).Compared with the control group,the expression level of E-cadherin in the lung tissue of rats in the PQ group decreased(P<0.05),the expression levels ofα-SMA and Vimentin increased(P<0.05),the protein expression level of Nrf2 decreased(P<0.05),the protein expression level of TGF-β1 and the phosphorylation levels of NF-κB p65 and Smad3 proteins increased(P<0.05).Compared with the PQ group,the expression levels of E-cadherin in the lung tissues of rats in the HYP-L group,the HYP-M group and the HYP-H group increased(P<0.05),the expression levels ofα-SMA and Vimentin decreased(P<0.05),the protein expression levels of Nrf2 increased(P<0.05),the protein expression level of TGF-β1 and the phosphorylation levels of NF-κB p65 and Smad3 proteins decreased(P<0.05).Conclusion Hyperoside effectively alleviates paraquat-induced acute lung injury in rats,and it may reduce lung oxidative stress,inflammation and fibrosis by regulating Nrf2,NF-κB and TGF-β1/Smad2/3 signal pathways.