富硒麦芽预防二乙基亚硝胺诱发大鼠肝癌的研究

Prevention on diethylnitrosamine-induced hepatocarcinogenesis by selenium-enriched malt in rats

采用100 mg.L-1二乙基亚硝胺(DEN)诱发大鼠肝癌16周,同时分别饲喂含0.3、1.0、3.0 mg.kg-1富硒麦芽硒和3.0 mg.kg-1亚硒酸钠(Na2SeO3)硒的饲料,停止诱癌及补硒处理2周后,处死大鼠,测定生化指标等,并用流式细胞术分析肝细胞增殖周期的变化。结果显示,3.0 mg.kg-1富硒麦芽组大鼠的肝/体重比、血浆丙氨酸氨基转移酶(ALT)、碱性磷酸酶(ALP)、总胆红素(TB IL)、γ-谷氨酰转肽酶(γ-GT)、谷胱甘肽硫转移酶(GST)显著低于模型组,肝癌结节数明显低于0.3、1.0 mg.kg-1富硒麦芽组和3.0 mg.kg-1Na2SeO3组,但ALT和γ-GT高于0.3 mg.kg-1富硒麦芽组;1.0 mg.kg-1和3.0 mg.kg-1的富硒麦芽组S期细胞较模型组明显减少,增殖指数(proliferation in-dex,PI)明显下降,而G0/G1期细胞明显增多。表明富硒麦芽具有减轻肝脏损伤、延缓大鼠肝癌形成的能力。其作用机制之一可能是阻滞G1期细胞向S期的进程,从而抑制DNA合成,阻止肝细胞分裂和恶性增殖。

Rats with hepatocarcinogenesis induced by 100 mg ·L^-1 diethylnitrosamine （DEN） for 16 weeks were fed with 0. 3, 1.0, 3.0 mg·kg^-1 selenium as selenium-enriched malt and 3. 0 mg ·kg^-1 selenium as sodium selenite at the same time. Then the rats fed with ordinary diet for another two more weeks were killed and the biochemical indexes were measured. The results indi- cated that the ratio of liver/body weight and plasma ALT, ALP, TBIL, γ-GT and GST in the group of 3.0 mg·kg^-1 selenium as selenium-enriched malt were significantly lower than those in the model group, the hepatoma nodules were significantly less than those in the groups of 0. 3 and 1.0 mg·kg^-1 selenium as selenium-enriched malt and 3, 0 mg ·kg^-1 selenium as sodium selenium, but plasma ALT and γ-GT were higher than those in the group of 0. 3 mg·kg^-1 selenium as selenium-enriched malt. Comparing with the model group, the percentage of S phase cells and the proliferation index （PI） in the 1.0 and 3.0 mg ·kg^-1 selenium as selenium-enriched malt groups were significantly decreased and the percentage of G0/G1 cells increased. It demonstrated that selenium-enriched malt attenuated the lesion of liver cells and delayed the development of hepatoma induced by DEN. One of the mechanisms might be to postpone advancement of G0/G1 phase cell to S phase, to inhibit DNA synthesis of hepatoma cell and to prevent cytodiaeresis and malignant proliferation of hepatocytes.