决明子总蒽醌对脂多糖诱导大鼠急性肝损伤的作用及其机制探讨

Protective effect of total anthraquinone in semen cassiae on acute liver injury induced by LPS in rats and its mechanism

目的观察决明子总蒽醌对脂多糖(LPS)诱导的急性肝损伤(ALI)大鼠的作用及对HMGB1/TLR4/NF-κB信号通路的影响。方法将60只大鼠随机分为对照组、模型组、低剂量组、中剂量组和高剂量组,除对照组外其余大鼠给予尾部静脉注射LPS(5 mg/kg)复制ALI模型,对照组给予等体积的生理盐水。低、中、高剂量组在模型复制后每日分别给予大鼠灌胃1次10 mg/kg、20 mg/kg及40 mg/kg的决明子总蒽醌,灌胃剂量5 ml,连续给药14 d;对照组和模型组给予同等体积生理盐水。检测大鼠丙氨酸氨基转移酶(ALT)、总胆红素(TBIL)及天门冬氨酸基转移酶(AST),HE染色观察肝组织病理变化,TUNEL染色检测各组大鼠肝组织中的细胞凋亡,ELISA法检测肝组织中的肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)及白细胞介素-1β(IL-1β),Western blotting检测高迁移率族蛋白B1(HMGB1)、Toll样受体4(TLR4)及核因子κB(NF-κB)蛋白表达量。结果模型组ALT、AST及TBIL水平较对照组升高(P<0.05),中、高剂量组较模型组下降(P<0.05)。模型组肝细胞凋亡率较对照组升高(P<0.05),中、高剂量组较模型组下降(P<0.05)。模型组肝组织中IL-6、IL-1β和TNF-α水平较对照组升高(P<0.05),中剂量组、高剂量组较模型组下降(P<0.05)。模型组HMGB1、TLR4及NF-κB蛋白相对表达量较对照组升高(P<0.05),中、高剂量组较模型组下降(P<0.05)。结论决明子总蒽醌可以抑制LPS诱导ALI大鼠的HMGB1/TLR4/NF-κB信号通路的激活,从而减轻炎症反应,发挥对肝脏的保护作用。

Objective To observe the protective effect of total anthraquinone in semen cassiae (TASC) on acute liver injury (ALI) induced by lipopolysaccharide (LPS) in rats and that on HMGB1/TLR4/NF-κB signaling pathway.Methods Sixty rats were randomly divided into control group,model group,low dose group,middle dose group and high dose group.All rats were given LPS (5 mg/kg) intravenously to establish ALI model except that the control group was instead administered saline of equal volume.The rats in the low,middle and high dose groups were respectively given 5 ml TASC in 10 mg/kg,20 mg/kg and 40 mg/kg once a day for consecutive 14 days,while the rats in the control group and the model group were given normal saline of the same volume.The alanine aminotransferase (ALT),total bilirubin (TBIL) and aspartate aminotransferase (AST) were detected to indicate the liver function of rats.Hematoxylin-eosin (HE) staining was applied to observe the liver tissue pathological changes.TUNEL assay was used to detect cell apoptosis in rat liver tissues.The tumor necrosis factor alpha (TNF-α),interleukin 6 (IL-6) and interleukin 1β (IL-1β) were determined with ELISA.Western blotting (WB) detected high mobility group B1 (HMGB1),toll-like receptor 4 (TLR4),and nuclear factor kappaB (NF-κB) proteins.Results Compared with the control group,the levels of ALT,AST,TBIL,IL-1β,IL-6,TNF-α and the expressions of HMGB1,TLR4 and NF-κB in the liver tissues of the model group were all increased,which suggested that the apoptosis in the liver cells of the rats was elevated (P<0.05).Besides,the levels of ALT,AST,TBIL,IL-1β,IL-6,TNF-α and the expression of HMGB1,TLR4 and NF-κB proteins in the liver tissues of rats in the middle and high TASC group were all decreased,indicating that the rat liver cells apoptosis was reduced (P<0.05) and that the protective effect of TASC on ALI was dose-dependent.Conclusions TASC can inhibit the activation of HMGB1/TLR4/NF-κB signal pathway in ALI rats induced by LPS,thus ameliorating the inflammatory response and protecting liver against the injury.