草苁蓉提取物对HepG2细胞氧化应激损伤的保护作用

Protective Effect of Boschniakia rossica Extract on Oxidative Damage in Hep G2 Cells

目的:研究草苁蓉乙醇提取物(Boschniakia rossica ethanol extract,BREE)对H2O2诱导的Hep G2细胞氧化应激损伤的保护作用。方法:用H2O2诱导Hep G2细胞氧化应激损伤,采用噻唑蓝(methylthiazolyldiphenyltetrazolium bromide,MTT)比色法检测BREE对Hep G2细胞氧化损伤的保护作用;比色法测定培养液中乳酸脱氢酶(lactate dehydrogenase,LDH)、谷丙转氨酶(alanine aminotransferase,ALT)、谷草转氨酶(aspartate aminotransferase,AST)的释放率,以及细胞中超氧化物歧化酶(superoxide dismutase,SOD)、还原型谷胱甘肽(reduced glutathione,GSH)及丙二醛(malondialdelyde,MDA)水平;蛋白印迹法测定细胞外信号调节蛋白激酶(extracellular signal-regulated kinase,ERK)、c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)、p38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38 MAPK)总蛋白及其磷酸化形式的表达水平以及核转录因子-κB(nuclear factor-κB,NF-κB)的核内转移。结果:BREE单独处理时,在所测质量浓度范围内对Hep G2细胞增殖无显著影响。与模型组相比,BREE能显著提高氧化损伤细胞的存活率;降低氧化损伤细胞培养液中LDH、ALT和AST的释放;降低细胞MDA水平,增高细胞SOD活性和GSH含量。氧化损伤发生的不同时期,ERK、JNK、p38 MAPK和NF-κB蛋白均有激活,而BREE在氧化损伤发生1 h时减少ERK激活和NF-κB核转移,氧化损伤发生12 h时减少JNK蛋白激活。结论:BREE对H2O2所致Hep G2细胞氧化应激损伤具有保护作用,此作用可能与其抑制ERK、JNK的活化和NF-κB的核内转移有关。

Objective： The protective role of ethanol extract of Boschniakia rossica （BREE） against cellular oxidative injury induced by hydrogen peroxide （H202） in HepG2 cell line was investigated. Methods： MTT assay was used to evaluate the cell proliferation of HepG2 cells. The activities of lactate dehydrogenase （LDH）, alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, malondialdelyde （MDA）, superoxide dismutase （SOD） and reduced glutathione （GSH） were measured by the spectrophotometric method. The total protein expression and the phospharylation of extracellular signal- regulated kinase （ERK）, c-Jun N-terminal kinase （JNK）, p38 mitogen-activated protein kinase （p38 MAPK）, and nuclear translocation of nuclear factor-κB （NF-κB） were determined by the Western blotting method. Results： BREE had no toxic effect on cultured HepG2 cells at the tested concentrations. In HepG2 cells with H202-induced oxidative damage, BREE increased cell viability, reduce LDH, ALT and AST leakage, inhibited MDA formation, and increased SOD and GSH levels. At the different stages of oxidative damage, ERK, JNK, p38 MAPK and NF-κB proteins were activated; however, the administration of BREE suppressed the ERK activation and NF-κB nuclear translocation at 1 h, and JNK activation at 12 h. Conclusion： BREE can function as an antioxidant to prevent cellular injury induced by H202 in cultured HepG2 cells, maybe via the suppression of ERK and JNK activation and NF-κB nuclear translocation.