【摘要】 为了探究β-谷甾醇对LPS诱导的急性肺损伤小鼠的保护作用及其可能的机制,利用酶联免疫吸附法(ELISA)测定β-谷甾醇对RAW 264.7细胞产生肿瘤坏死因子(TNF-α)和白细胞介素-6(IL-6)的影响。给BALB/c小鼠鼻腔滴注LPS(0.5mg/kg)构建小鼠急性肺损伤模型,滴鼻24 h后检测各指标。ELISA检测小鼠肺泡灌洗液中(BALF)的炎性细胞因子含量;称重法检测肺组织湿/干重比和肺含水量;HE染色法观察肺组织病理形态学变化;应用蛋白印迹法(western blot)检测小鼠肺脏中核转录因子-κB(NF-κB)信号转导通路中相关蛋白的含量变化。结果表明,β-谷甾醇能剂量依赖性降低RAW 264.7细胞上清及ALI小鼠BALF中TNF-α和IL-6的表达水平。肺脏称重结果和病理形态学结果显示β-谷甾醇可明显减轻LPS诱导的肺水肿和炎症反应。另外,western blot结果表明β-谷甾醇不仅能够下调NF-κB p65的活化,还抑制了NF-κB阻断剂IκBα的磷酸化。β-谷甾醇对LPS所致的小鼠急性肺损伤有较好的保护作用,其保护机制可能与阻止炎症因子(TNF-α、IL-6)的释放和下调NF-κB信号转导通路的活化有关。更多还原

【Abstract】 The paper aims to investigate the mechanism and protective effects of β-sitosterol on mice withLipopolysaccharide(LPS)-induced acute lung injury(ALI). We evaluated the effect of β-sitosterol on LPS-induced production of TNF- α and interleukin(IL)- 6 in the culture supernatants of RAW 264.7 cells byenzyme-linked immunosorbent assay(ELISA). Model of ALI in BALB/c mice was built by LPS(0.5 mg/kg)intranasal instillation and the severity of pulmonary injury was evaluated 24 h after LPS challenge. Theinflammatory cytokines were assayed with ELISA in bronchoalveolar lavage fluid(BALF); the ratio of lung wetweight to dry weight(W/D) and water content were also measured; lung tissues were stained withHematoxylineosin to observe the pathological. In addition,the activity changes of nuclear factor-κB(NF-κB)were detected by western blot. β-sitosterol could dose-dependently decrease the levels of TNF-α and IL-6 in vitro and in vivo. Pretreatment with β-sitosterol was found to decrease the W/D ratio and water content of thelung tissue and suppress lung edema and pulmonary alveolar damage at the same time. In addition, β-sitosterol suppressed not only the phosphorylation of NF-κB but also the degradation of its inhibitor(IκBα). β-sitosterolhad good protective effect against ALI induced by LPS, and its mechanism might be related with down-regulated inflammatory cytokines(TNF-α, IL-6) and NF-κB expressions.更多还原