乙氧喹对脂多糖和D-氨基半乳糖诱导小鼠急性肝损伤的保护作用

Protective Effects of Ethoxyquin on Lipopolysaccharide and D-Galactosamine Induced Acute Liver Injury of Mice

本试验运用脂多糖(LPS)和D-氨基半乳糖(D-GalN)建立小鼠急性肝损伤模型,以阐述乙氧喹在体内的抗氧化作用和机制。将40只昆明小鼠随机分为5组:空白组、模型组以及乙氧喹低(50μg/kg)、中(100μg/kg)、高剂量(200μg/kg)组,每组8只。乙氧喹各剂量组连续腹腔注射给药3 d,空白组和模型组用生理盐水做同样处理。在第3天给药1 h后,除空白组外,其余各组小鼠腹腔注射LPS(500μg/kg)和D-GalN(500 mg/kg)。4 h后收集各组小鼠血液,检测血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)活性;采集肝脏组织样本,观察肝脏组织病理变化,同时检测肝脏谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)活性和丙二醛(MDA)含量;定量逆转录PCR检测肝脏肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)和白细胞介素-6(IL-6) mRNA相对表达水平,蛋白免疫印迹(Western Blot)检测肝脏核因子-κB(NF-κB)和核因子E2相关因子2(Nrf2)信号通路相关蛋白的表达。结果表明:与模型组相比,乙氧喹低、中、高剂量组的血清ALT和AST活性显著降低(P<0.05),肝脏组织病理损伤减轻,肝脏MDA含量和MPO活性显著降低(P <0.05),肝脏GSH-Px活性显著增加(P <0.05),肝脏TNF-α和IL-6的mRNA相对表达水平显著下调(P <0.05),肝脏p65蛋白磷酸化水平显著降低(P<0.05),肝脏Nrf2和血红素氧合酶-1(HO-1)蛋白表达水平显著升高(P<0.05)。综上所述,乙氧喹可能通过抑制小鼠体内NF-κB信号通路,并激活Nrf2信号通路,从而减缓LPS和D-GalN引起的氧化应激与炎症反应,从而呈现出对肝脏的保护作用。

This experiment used lipopolysaccharide(LPS)and D-galactosamine(D-GalN)to establish a mouse model of acute liver injury,to illustrate the antioxidant effect and mechanism of ethoxyquin in vivo.Forty Kunming mice were randomly divided into the following 5 groups:control group,model group and ethoxyquin low(50μg/kg),medium(100μg/kg)and high dose(200μg/kg)groups,each group contained 8 mice. Each ethoxyquin dose group was given by continuous intraperitoneal injection for 3 days,and the control group and model group were treated with normal saline in the same way. After 1 h of administration on the 3rd day,except for the control group,the mice in other groups were intraperitoneally injected with LPS(500μg/kg)and D-GalN(500 mg/kg). After 4 h,the blood of mice of each group was collected,and the serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST)activities were detected. The liver tissue samples were collected,then observed the pathological changes of liver tissues. The glutathione peroxidase(GSH-Px),superoxide dismutase(SOD),myeloperoxidase(MPO)activities and malondialdehyde(MDA)content in liver were determined. The quantitative reverse transcription PCR was used to detect the mRNA relative expression level of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interleukin-6(IL-6)in liver,and Western Blot was used to detect the related protein expression of nuclear factor-kappa B(NF-κB)and nuclear factor erythroid-2 related factor 2(Nrf2)signaling pathways in liver. The result showed that compared with the model group,the serum ALT and AST activities of ethoxyquin low,medium and high dose groups were significantly decreased(P<0.05),the pathological damage of liver tissue was alleviated,the MDA content and MPO activity in liver were significantly decreased(P<0.05),the liver GSH-Px activity was significantly increased(P<0.05),the mRNA relative expression levels of TNF-α,IL-1β and IL-6 were significantly down-regulated(P<0.05),the phosphorylation level of p65 protein in liver was significantly decreased(P<0.05),and the Nrf2 and heme oxygenase-1(HO-1)protein expression levels were significantly increased(P<0.05). In conclusion,ethoxyquin may exhibit a protective effect on liver by inhibiting the NF-κB signaling pathway and activating the Nrf2 signaling pathway to attenuate the oxidative stress and inflammation caused by LPS and D-GalN in mice.