中文摘要：

[目的]观察正肝方对黄曲霉毒素B1（AFB1）诱发的大鼠癌前病变肝组织细胞周期蛋白D1（Cyclin D1）、细胞周期蛋白依赖性激酶4（CDK4）的影响。[方法]Wistar大鼠100只随机分为4组：模型、正肝方小剂量、正肝方大剂量组各30只、正常组10只。除正常组外,先后用AFB1和2-乙酰氨基芴（2-AAF）处理各组大鼠造模。正肝方大、小剂量组在造模期间,将正肝方水剂（0.6、0.3 g/ml）按10 ml/kg分别灌胃;模型组用无菌蒸馏水按10 ml/kg灌胃。8周后处死大鼠,肝组织取材。分别采用免疫组化法和RT-PCR法,检测大鼠肝组织中Cyclin D1、CDK4蛋白和mRNA表达。[结果]模型组Cyclin D1、CDK4染色阳性细胞百分率（LI）和表达强度（PU）最高,Cyclin D1、CDK4mRNA表达水平也最高（P〈0.01）。正肝方能降低大鼠癌前病变肝组织Cyclin D1、CDK4蛋白和mRNA的异常高表达（P〈0.01或〈0.05）,且呈现出一定的量效关系。[结论]正肝方能通过下调Cyclin D1、CDK4异常表达,改善细胞周期G1~S期调控点失控,从而减缓肝细胞异常增生。

英文摘要：

[Objective]To observe the effects of Zhengganfang（ZGF）on Cyclin D1 and CDK4 in hepatic precancerous lesion tissue of rats.[Methods]One hundred wistar rats were divided into four groups randomly：model group,ZGF low-dosage group,ZGF high-dosage group and normal control group.AFB1 and 2-AAF were successively used for making model.During the period of making model,the rats in ZGF low-dosage group and high-dosage group were fed with ZGF at respective dosage.All rats were sacrificed after eight-week treatment,thereafter the autopsied liver tissues from each rat were prepared for checking Cyclin D1 and CDK4 by immunohistochemistry method and RT-PCR.[Results]Both the protein and the mRNA expression of Cyclin D1 and CDK4 in model group were the highest in four groups（P0.01）.ZGF could lessen the abnomal high expression of Cyclin D1 and CDK4 in hepatic precancerous lesion tissue（P0.01 or P0.05）,and the function of lessening showed dose-effect relationship.[Conclusion]ZGF can effectively improve the G1-S period of cell cycle by down-regulation of the abnomal expression of Cyclin D1 and CDK4,and therefore the hyperplasia of hepatocyte can slow down.