甘草酸对H2O2诱导小肠上皮细胞DNA损伤的保护作用

目的 初步研究甘草酸(Glycyrrhizic acid,GA)对氧化损伤小肠上皮细胞IEC-6的保护作用及可能机制.方法 实验设空白对照组,H2O2模型组,GA低、中、高剂量组(50,100,200 μg/mL).GA各组加入相应浓度的药物作用48 h后,与模型组一起加入200 μmol/L的H2O2作用2h,空白对照组正常培养.用单细胞凝胶电泳检测DNA损伤,RT-PCR检测p53,Gadd45α mRNA表达,Western blot检测p53,Gadd45α蛋白表达.结果 与空白对照组比较,模型组DNA损伤严重,Gadd45α mRNA和蛋白表达增高;与H2O2模型组比较,GA各组DNA损伤明显减轻,GA1 00μg/mL和200 μg/mL组p53 mRNA及其蛋白表达明显升高,同时Gadd45α mRNA及其蛋白表达明显升高.结论 GA在100～200 μg/mL可以保护H2O2诱导的小肠上皮细胞DNA损伤,其机制可能与p53和Gaad45α的表达增高相关.

Effect of Glycyrrhizic Acid on Protecting Instestinal Epithelial Cells from H2O2-induced DNA Damage

Objective To observe the protective effect of glycyrrhizic acid(GA) on DNA damage of intestinal epithelial cells(IEC-6) induced by H2O2,and to investigate the potential mechanism.Methods Five groups including blank control,H2O2 model,GA50 μg/mL,GA100 μg/mL,GA200 μg/mL groups were set up in this study.Cells were cultured with blank control medium or GA of the fixed dosages for 48h,and then were stimulated with 200 μmol/L H2O2 for 2 h.DNA damage was analyzed by single cell gel electrophoresis assay.P53,Gadd45α mRNA was evaluated by RT-PCR.Expression of p53 and Gadd45α protein was detected by western blot.Results Compared with the blank control group,DNA of IEC-6 in the the H2O2 model group was severely damage,and Gaad45α mRNA and protein expression was increased.After treatment with GA of 100 μg/mL or 200 μg/mL for 48 h,DNA damage reduced significantly,expression of p53 mRNA and protein both increased.Meanwhile,Gadd45α mRNA and protein expression was also increased.Conclusion The above results indicated GA of 100～200 μg/mL protects IEC-6 from DNA damage induced by H2O2,which mechanism is probably related with the increase of p53 and Gadd45α expression.