茶多酚对酒精性肝病大鼠核因子κB及环氧合酶2表达的影响

Effect of Tea Polyphenols on Expression of Nuclear Factor κappa B and Cyclooxygenase 2 in Rats with Alcoholic Liver Diseases

目的观察茶多酚对大鼠酒精性肝病的干预作用及其对核因子κB(NF-κB)和环氧合酶2(COX-2)表达的影响。方法32只Wistar大鼠,随机分为3组,对照组(6只)用玉米油;模型组(13只)用白酒+玉米油;茶多酚组(13只)在模型组基础上给予茶多酚。7周后处死大鼠,检测血清中天门冬氨酸转氨酶(AST)、丙氨酸转氨酶(ALT)和丙二醛(MDA)含量。光镜和电镜观察肝组织细胞及亚细胞结构的改变;逆转录聚合酶链反应(RT-PCR)测肝组织中NF-κB及COX-2的mRNA表达;免疫组织化学法检测肝组织中NF-κB和COX-2蛋白的表达。结果模型组肝细胞损伤明显,茶多酚组较轻。模型组大鼠血清ALT较对照组明显升高(P<0.01);与模型组相比,茶多酚组大鼠血清ALT、AST、MDA明显降低(P<0.01)。RT-PCR及免疫组化均显示,肝组织中NF-κB及COX-2表达模型组较对照组明显升高(P<0.01),茶多酚组较模型组明显降低(P<0.01)。结论茶多酚对大鼠酒精性肝损伤有保护作用,可能是通过抑制NF-κB的活化和COX-2的表达来实现的。

Objective To investigate the effect of tea polyphenols （TP） on expression of nuclear factor kappa B （NF-kB） and cyclooxygenase 2 （COX-2） in rats with alcoholic liver diseases. Methods 32 female Wistar rats were randomly divided into three groups： control group treated with corn oil, model group with alcohol and corn oil, TP group with corn oil and alcohol plus TP. All treatments were administered into the stomach intragastrically. Liver samples were analyzed for histopathology with light （LM） and transmission electron microscopy （TEM）, and the expression of NF-kB and COX-2 with RT-PCR and immunohistochemistry. Levels of serum aspartate aminotransferase （AST）, alanine aminotransferase （ALT） and malonaldehyde （MDA） were measured. Results LM and TEM observed that the hepatocytes were injured obviously in the model group and slightly in the TP group. The level of serum ALT increased significantly in the model group （p〈0.01） compared with that in the control group. To compare with the model group, the levels of ALT, AST and MDA decreased significantly （p〈0.01）. NF-kB and COX-2 expression in the liver determined by RT-PCR and immunohistochemistry increased significantly in the model group in comparison with the control group （p〈0.01） and TP group （p 〈 0.01 ） . Conclusion TP can diminish alcohol-induced liver injury in rats through inhibiting NF-kB activation and decreasing COX-2 level.