甘草酸对大鼠肝星状细胞氧化应激抑制作用的机制研究

Inhibitory effect of glycyrrhizic acid on oxidative stress in rat hepatic stellate cells

目的探讨甘草酸对大鼠肝星状细胞(HSC)的氧化应激及核转录因子E2相关因子2(Nrf2)/血红素加氧酶(HO)-1信号通路的影响。方法体外培养HSC细胞,将细胞分为5组:空白对照组、次氮基三乙酸铁(Fe-NTA)处理组、Fe-NTA+5μmol/L甘草酸组、Fe-NTA+10μmol/L甘草酸组及Fe-NTA+20μmol/L甘草酸组;给药24 h后收集细胞,采用相关试剂盒检测HSC细胞中丙二醛(MDA)、一氧化氮(NO)、谷胱甘肽(GSH)的含量及超氧化物歧化酶(SOD)的活性;RT-PCR和Western blot方法分别检测Nrf2和HO-1 mRNA及蛋白表达水平。结果 Fe-NTA处理组中MDA、NO含量明显升高,而GSH水平显著降低,SOD酶活性也显著降低;而甘草酸处理的3组细胞中MDA、NO含量显著降低,GSH水平显著升高,SOD酶活性也显著升高,差异均有统计学意义(P<0.05)。Fe-NTA处理组中Nrf2和HO-1mRNA及蛋白表达水平与空白对照组比较显著降低,而甘草酸处理的3组细胞中Nrf2和HO-1mRNA及蛋白表达水平相对于Fe-NTA处理组显著上调,差异均有统计学意义(P<0.05)。结论甘草酸有抗HSC细胞氧化应激损伤的作用,其作用机制可能与激活Nrf2/HO-1信号通路有关。

Objective To investigate the effect of glycyrrhizic acid（ GA） on oxidative stress and the Nrf2/HO-1 signaling in rat hepatic stellate cells（ HSCs）. Methods HSCs were cultured in vitro and divided into five groups,including the control group,Fe-NTA group,Fe-NTA＋5 μmol/L GA group,Fe-NTA＋ 10 μmol/L GA group and Fe-NTA＋20 μmol/L GA group. The levels of MDA,NO,GSH and the activity of SOD were measured. The expression levels of Nrf2 and HO-1 mRNA and proteins were analyzed using RT-PCR and Western blot. Results Compared with the control group,the levels of MDA and NO in HSCs were increased but GSH levels and SOD activities were decreased in Fe-NTA group. After treatment with different concentrations of GA, the levels of MDA and NO were significantly decreased but GSH levels and SOD activities were increased. The expression of Nrf2 and HO-1 in HSCs treated with GA was obviously enhanced compared with Fe-NTA group（ P〈0.05）. Conclusion GA protects HSCs against oxidative stress injury,which may be related to activation of the Nrf2/HO-1 signaling pathway.