熊去氧胆酸对大鼠肝癌发生的抑制作用及机制

Inhibition effect of ursodesoxycholic acid on hepatocarcinogenesis of rats and its mechanism

目的研究熊去氧胆酸(UDCA)对大鼠肝癌发生的抑制作用并探讨其机制。方法利用二乙基亚硝胺(DEN)诱导大鼠肝癌模型,75只雄性Wistar大鼠随机分为5组:正常对照组、UDCA对照组、DEN组、UDCA高和低剂量组。DEN组及UDCA高低剂量组均给予DEN腹腔注射(20 mg/kg),正常对照组及UDCA对照组给予等剂量的生理盐水腹腔注射。同时UDCA对照组及UDCA高低剂量组分别按30、30、15 mg/kg给予UDCA灌胃,正常对照组及DEN组给予等量生理盐水灌胃。观察大鼠肝质量、体质量及肝脏系数的变化;并检测血清中丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)及甲胎蛋白(AFP)的含量;采用实时定量RT-PCR检测不同组间DNA损伤修复基因hMTH1在大鼠肝脏中的表达。结果与正常对照组相比,DEN组大鼠的体质量明显降低,肝质量和肝脏系数明显增加,ALT、AST及AFP的含量均明显升高(P<0.05);与DEN组相比,UDCA高低剂量组各项指标明显好转。实时定量RT-PCR显示,hMTH1在DEN组大鼠肝脏中的表达较正常对照组明显升高(P<0.05);UDCA高低剂量组大鼠肝脏中hMTH1的表达较DEN组明显降低(P<0.05);且hMTH1在UDCA高剂量组中的表达也较UDCA低剂量组明显降低(P<0.05)。UDCA对照组与正常对照组相比,各项指标无统计学差异。结论 UDCA对大鼠肝癌发生有抑制作用,并能够抑制DNA损伤修复基因hMTH1的表达,其效果和剂量呈正相关,提示UDCA对肝癌的抑制作用可能与抑制氧化应激有关。

Objective To investigate the inhibitory effect of ursodeoxycholic acid （UDCA） on hepatocarcinogenesis of rats and explore its mechanism. Methods The hepatocarcinoma was induced by diethylnitrosamine （DEN） . Seventyfive male wistar rats were randomly divided into the normal control group, the UDCA control group, the DEN group and two UDCA intervention groups. The DEN group and the UDCA intervention groups were given an intraperitoneal injection of 20mg/kg body weight of DEN. The normal control group and the UDCA control group were given a same dose of saline. At the same time, UDCA were separately given to the UDCA control group and the UDCA high and low dose groups according to 30 mg/（kg ·d）, 30 mg/（kg · d ） and 15（mg/kg · d）, the normal control group and the DEN group was given equivalent physiological saline. Changes of body weight, liver weight, organ coefficient of liver, ALT, AST and AFP in serum were observed and detected. Real-time quantitative RT-PCR was used to detect DNA repair enzyme hMTH1 in rat livers. Results Compared with those of the normal control group, body weights significantly decreased and liver weights, organ coefficients of liver, the activities of ALT, AST and the content of AFP in serum significantly increased in the DEN group（P 〈 0.05）. Compared with those of the DEN group, all indicators were significantly improved in the UDCA intervention groups （ P 〈 0.05 ）. Compared with that of the normal control group, the expression of hMTH1 was significantly higher in the DEN group and the UDCA intervention group（ P 〈0.05 ）. But the expression of hMTH1 were significantly lower in UDCA intervention group compared with DEN group（ P 〈 0.05 ） ; the expression of hMTH1 was significantly lower in the UDCA high dose group compared with that of the UDCA low dose group （P 〈 0.05 ）. There was no difference between the UDCA control group and the normal control group. Conclusion UDCA can inhibit the development of hepatocarcinoma induced by DEN and the expression of hMTH1, which is positively related to dosage. Its mechanisms may be that UDCA can inhibit oxidative stress.