红景天苷混悬液灌胃对小鼠急性放射性肺损伤的改善作用及其作用机制

Effect and mechanism of salidroside suspension on acute radiation-induced lung injury in mice

目的观察红景天苷(SAL)混悬液灌胃对小鼠急性放射性肺损伤(RILI)的改善作用,探讨其可能作用机制。方法将48只C57BL/6J雄性小鼠随机分为低剂量组、中剂量组、高剂量组、地塞米松(DXM)组、模型组及对照组,每组8只。除对照组外,其余五组小鼠用医用直线加速器6 MV-X线行全胸单次照射,在照射后第2天低剂量组、中剂量组、高剂量组小鼠分别予15、30、60 mg/kg的SAL混悬液灌胃(1次/天,连续7 d),DXM组小鼠予10 mg/kg的DXM灌胃(1次/天,连续7 d),对照组和模型组小鼠予等体积生理盐水灌胃(1次/天,连续7 d)。灌胃结束后第2天,抽取各组小鼠外周静脉血,处死小鼠后留取肺组织。HE染色后观察各组小鼠肺组织形态学变化;采用ELISA法检测小鼠血清炎性因子[白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)];采用实时荧光定量PCR法检测小鼠肺组织中IL-1β、IL-6、TNF-α的mRNA;采用Western Blotting法检测小鼠肺组织核因子E2相关因子2(Nrf2)、血红素加氧酶-1(HO-1)、谷胱甘肽过氧化物酶4(GPX4)、转化生长因子β(TGF-β)。结果低、中、高剂量组小鼠肺组织损伤均有不同程度的改善,高剂量组小鼠肺组织损伤改善程度最明显;与高剂量组相比,DXM组小鼠肺组织损伤改善更明显;与对照组相比,模型组小鼠肺组织肺泡间隔弥漫增厚、水肿,肺泡腔明显缩小甚至消失,正常结构明显破坏。与对照组相比,模型组小鼠血清IL-1β、IL-6、TNF-α水平升高(P均<0.05);与模型组相比,中、高剂量组和DXM组小鼠血清IL-1β、IL-6、TNF-α水平降低(P均<0.05)。与模型组相比,中、高剂量组和DXM组小鼠肺组织IL-1β、IL-6、TNF-α的mRNA相对表达量低(P均<0.05)。与对照组相比,模型组小鼠肺组织Nrf2、HO-1和GPX4表达升高,TGF-β表达降低(P均<0.05);与模型组相比,中高剂量组和DXM组小鼠肺组织Nrf2、HO-1和GPX4表达升高,TGF-β表达降低(P均<0.05)。结论SAL混悬液灌胃可改善小鼠急性RILI(其中60 mg/kg的SAL混悬液效果最好)。SAL混悬液对小鼠急性RILI的改善作用机制可能是SAL促进肺组织Nrf2、HO-1蛋白表达,减轻小鼠氧化应激和炎症反应。

Objective To observe the improvement effect of intragastric administration of salidroside(SAL)suspension on acute radiation-induced lung injury(RILI)in mice and to investigate its possible mechanism.Methods Fortyeight C57BL/6J male mice were randomly divided into the low-dose group,medium-dose group,high-dose group,dexamethasone(DXM)group,model group,and control group,with 8 mice in each group.Except for the control group,mice in the other five groups were irradiated with 6 MV-X ray from a medical linear accelerator.On the second day after irradiation,the mice in the low-dose group,medium-dose group and high-dose group were given 15,30 and 60 mg/kg SAL suspension(once a day,for 7 days),and the mice in the DXM group were given 10 mg/kg DXM(once a day,for 7 days),mice in the normal control group and the model group were both given the same volume of normal saline(once a day,for 7 days).On the second day after the end of intragastric administration,peripheral venous blood of mice in each group was taken,and the lung tissues were taken after the mice were killed.The morphological changes of the lung tissues in each group were observed after HE staining.Serum inflammatory factors[interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)]were detected by ELISA.The mRNA levels of IL-1β,IL-6 and TNF-αin the lung tissues of mice were detected by real-time fluorescence quantitative PCR.Western blotting was used to detect nuclear factorerythroid 2-related factor 2(Nrf2),heme oxygenase-1(HO-1),glutathione peroxidase 4(GPX4)and transforming growth factorβ(TGF-β)in the lung tissues of mice.Results The lung tissue injury of mice in low-,medium-and high-dose groups was improved to different degrees with the most significant improvement in the high-dose group.Compared with the high-dose group,the improvement of lung tissue injury in the mice of the DXM group was more obvious.Compared with the control group,the pulmonary alveolar septa in the model group were diffusely thickened and edematous,the alveolar cavity was obviously reduced or even disappeared,and the normal structure was obviously destroyed.Compared with the control group,the serum levels of IL-1β,IL-6 and TNF-αincreased in the model group(all P<0.05).Compared with the model group,the serum levels of IL-1β,IL-6 and TNF-αdecreased in the medium-and high-dose groups and DXM group(all P<0.05).Compared with the model group,the relative mRNA expression levels of IL-1β,IL-6 and TNF-αin the lung tissues of mice were lower in the medium-and high-dose groups and DXM groups(all P<0.05).Compared with the control group,the expression levels of Nrf2,HO-1 and GPX4 in the lung tissues of the model group increased,while the expression of TGF-βdecreased(all P<0.05).Compared with the model group,the expression levels of Nrf2,HO-1 and GPX4 in the lung tissues increased,while the expression of TGF-βdecreased in the medium-and high-dose groups and DXM group(all P<0.05).Conclusions Intragastric administration of SAL suspension can improve acute RILI in mice(60 mg/kg SAL suspension has the best effect).The mechanism of SAL suspension in improving acute RILI in mice may be that SAL promotes the expression of Nrf2 and HO-1 protein in the lung tissue and reduces oxidative stress and inflammatory reaction in mice.