Effect Of Tea Polyphenols On Expression Of Nuclear Factor Kappa B And Cyclooxygenase2 In Rats With Alcoholic Liver Diseases

Objective By setting up rat models of alcoholic liver disease and intervene with tea polyphenols, to observe the pathology,ultramicro -structure changes, and to investigate the variation of liver damage index and lipid peroxidation,also to analyze the expression of NF-κB and COX-2 in liver tissue with RT-PCR and immunohistochemistry. Thus to investigate the effect of tea polyphenols on expression of nuclear factorκappa B and cyclooxygenase2 in rats with alcoholic liver diseases.Methods Thirty-two female Wistar rats weighting between 200g and 250g were divided into three groups randomizedly:control group,model group and tea polyphenols intervention group.The model group rats were given alcohol plus corn oil 2g·kg^-1·d^-1 through intragastric administration.The outset dose of alcohol was 8mL·kg^-1·d^-1, 2mL·kg^-1·d^-1 was increased per week until the total dose reached 16 mL·kg^-1·d^-1. tea polyphenols intervention group with corn oil and alcohol plus tea polyphenols 0.25g·kg-1.The control group rats were only given corn oil. During the experiment period,the rats fed with basic animal food.All the groups were treated for seven weeks.Then they were killed respectively and determinated the hepatic function paramenters and lipid peroxidation index:ALT,AST,MDA content in serum.Liver tissue spice was dyed by HE and SudanⅣ,then analyzed under light microscope.The ultramicro- Structure changes were observed under transmission electron microscope. The mRNA expression and protein content in liver tissue of NF-κB and COX-2 were measured by semiquantitative RT-PCR and immunochemistry.Results 1.In the model group rats,many drops of lipids infiltration were seen throughout the liver tissue after alcohol infusion for 7 weeks,the index such as ALT,AST, NF-κB and COX-2 increase significantly compared with control group,P<0.05. 2.The tea polyphenols intervention group get better in AST,ALT and MDA(P<0.01),and has lower HE scores(P<0.01).The severity of ultramicro-Structure displayed changes paralled with the pathology severity.There were decreased expression of NF-κB and COX-2 compared with model group.Conclusion Long-term intaking of ethanol would damage liver, Oxidative Stress and lipid peroxidation participat in the formation of alcoholic liver disease.Tea polyphenols can diminish alcohol-induced liver injury in rats through inhibiting NF-κB activation,decreasing COX-2 level,reducing lipid peroxidation and inflammatory reaction.