α、β、γ、δ-生育酚对小鼠急性四氯化碳肝损伤保护作用的研究

PROTECTION OF α,β,γ AND δ-TOCOPHEROLS AGAINST ACUTE LIVER INJURY INDUCED BY CARBON TETRACHLORIDE IN MICE

目的研究α、β、γ、δ-生育酚对四氯化碳(CCl_4)肝损伤小鼠的保护作用。方法将60只健康雄性ICR小鼠随机分成6组:正常组(NG)、CCl_4模型组(MG)、α-生育酚组(α-T)、β-生育酚组(β-T)、γ-生育酚组(γ-T)和δ-生育酚组(δ-T)。各生育酚组分别给予相应的羧甲基纤维素钠(CMC-Na)生育酚混悬液[100 mg/(kg·d)],NG组和MG组每日给予等量CMC-Na溶液灌胃,连续2w。末次灌胃2h后,正常组腹腔注射橄榄油,其余各组腹腔注射0.5%CCl_4橄榄油溶液。16h后处死小鼠,收集血清和肝脏。试剂盒测定小鼠血清谷丙转氨酶(ALT)、总胆固醇(TC)、甘油三酯(TG)水平及肝组织丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)的含量;荧光定量法测定肝脏SOD、CAT、GSH-Px基因相对表达量;光学显微镜观察小鼠肝脏病理学变化。结果与MG组相比,α-T组小鼠血清ALT、TG水平及肝脏MDA含量均显著降低,肝脏SOD、GSH-Px、CAT活力及m RNA表达量均显著升高;β-T组小鼠血清ALT、TG水平及肝脏MDA水平均显著降低,肝脏SOD水平显著升高;γ、δ-T组小鼠肝脏MDA水平亦显著降低。小鼠肝脏病理切片观察显示,各生育酚组较MG组有不同程度的改善。结论生育酚异构体对四氯化碳肝损伤小鼠有不同程度的保护作用,α-生育酚和β-生育酚的效果较好,其机理可能与其抗氧化作用相关。

Objective To investigate the protective effects of α, β, γ and δ-tocopherols against CCl4 induced acute liver injury in mice. Methods Sixty mice were randomly divided into six groups： normal group（NG）, model group（MG）, α-tocopherol group（α-T）、β-tocopherol group（β-T）、γ-tocopherol group（γ-T） and δ-tocopherol group（δ-T）. Tocopherols（100mg/kg·d）, suspended in 0.5% CMC-Na solution, were administered by gavage in tocopherol groups, and 0.5% CMC-Na were also administered by gavage for two weeks in normal and model groups, respectively,. Two hours after the last administration, mice in all groups except in the NG group were injected intraperitoneally with 0.5% CCl4 olive oil solution. The mice were then sacrificed 16 hours after the injection to collect serum and liver tissues. Serum alanine aminotransferase（ALT）, total cholesterol（TC）, triglyceride（TG） levels and hepatic malonaldehyde（MDA）, superoxide dismutase（SOD）, glutathione peroxidase（GSH-Px）, catalase（CAT） levels were measured by biochemical kits. Relative m RNA expression of SOD, CAT and GSH-Px were determined by real-time fluorescence quantitative PCR, and the ultrastructure of liver tissues were observed by light microscope. Results Compared with mice in MG group, mice pretreated with α-tocopherol had significantly reduced serum ALT, TG and hepatic MDA levels, and significantly elevated hepatic activity and m RNA expression of SOD, GSH-Px and CAT. Mice in β-T group had significantly reduced serum levels of ALT, TG and hepatic MDA, and significantly increased level of hepatic SOD. Mice in γ, δ-T groups had significantly decreased hepatic MDA level. Besides, the degree of liver damage was more or less improved in all tocopherol groups. Conclusion Tocopherol isomers could protect against acute liver injury induced by CCl4 in mice. The effects of α-tocopherol and β-tocopherol were better than the others, which may be related to their antioxidant function.