Preliminary Study of Oxidative Stress in Human Hepatocellular Carcinoma and Adjacent Normal Liver Tissues

OBJECTIVE The antioxidative system in human hepatocellular carcinoma was investigated. METHODS The activities of cytosolic catalase (CAT), superoxide dismu-tase, glutathione peroxidase (GSH-Px), glutathione S-tranferase and levels of reduced glutathione, total protein thiols and malondialdehyde were assayed in 10 cases of hepatocellular carcinoma and adjacent normal liver. RESULTS Hepatoma tissues showed higher activities of CAT, GSH -Px and lower content of total antioxidative capacity compared to adjacent normal liver tissue (P<0.05). CONCLUSION These findings suggest that the antioxidative defense-related enzymes and antioxidants are largely regulated in hepatoma cells. However, the mechanism which is not clear requires further investigation.

Protection of Salvianolic Acid B for Human Endothelial Cells Against Hydrogen Peroxide-Induced Oxidative Damage

Salvianolic acid B(Sal B) is an active component of traditional Chinese medicine Salvia miltiorrhiza and is used to treat vascular diseases. To better understand its mechanism, the antioxidant capacities of Sal B was evaluated with human endothelial cells under oxidative stress. Human endothelial cells were pretreated with Sal B for 12 h followed by hydrogen peroxide for another 12 h. Production of reactive oxygen species (ROS), activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and concentration of glu-tathione were measured. Protective effect of Sal B on the endothelial cells from hydrogen peroxide-induced damage was observed, and ROS production in the cells was found significantly inhibited. Sal B remarkably enhanced the activities of antioxidant enzymes SOD, CAT and GPX. Furthermore, Sal B up-regulated the intracellular glu-tathione concentration. The results indicate that Sal B protected endothelial cells from oxidative stress by improving the redox status of the cells through enhancing the antioxidant enzyme activities and increasing the reductive glu-tathione concentration after the oxidative challenge.

Piper sarmentosum as an antioxidant on oxidative stress in human umbilical vein endothelial cells induced by hydrogen peroxide

Endothelial cell death due to increased reactive oxygen species(ROS) may contribute to the initial endothelial injury,which promotes atherosclerotic lesion formation.Piper sarmentosum(PS),a natural product,has been shown to have an antioxidant property,which is hypothesized to inhibit production of ROS and prevent cell injury.Thus,the present study was designed to determine the effects of PS on the hydrogen peroxide(H2O2)-induced oxidative cell damage in cultured human umbilical vein endothelial cells(HUVECs).In this experiment,HUVECs were obtained by collagenase perfusion of the large vein in the umbilical cord and cultured in medium M200 supplemented with low serum growth supplementation(LSGS).HUVECs were treated with various concentrations of H2O2(0-1000 μmol/L) and it was observed that 180 μmol/L H2O2 reduced cell viability by 50% as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay.Using the above concentration as the positive control,the H2O2-induced HUVECs were concomitantly treated with various concentrations(100,150,250 and 300 μg/ml) of three different extracts(aqueous,methanol and hexane) of PS.Malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GPX) levels showed a significant increase(P<0.05) in HUVECs compared to the negative control.However,PS extracts showed a protective effect on HUVECs from H2O2-induced cell apoptosis with a significant reduction in MDA,SOD,CAT and GPX levels(P<0.05).Furthermore,PS had exhibited ferric reducing antioxidant power with its high phenolic content.Hence,it was concluded that PS plays a beneficial role in reducing oxidative stress in H2O2-induced HUVECs.

晚期人肝癌和癌旁组织中抗氧化酶及相关指标的测定及其意义

目的:研究肝癌晚期切除样品及其癌旁正常组织抗氧化酶及相关指标,探讨氧化应激反应水平在肝癌发展中的作用。方法:测定癌组织和癌旁正常组织中过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、谷胱甘肽硫转移酶(GST)活性及谷胱甘肽(GSH)、蛋白总巯基、脂质过氧化产物丙二醛(MDA)和总抗氧化能力(T-AOC)的含量(P<0.05)。结果:肝癌组织CAT和GSH-Px的活性显著高于相应的周围正常肝组织。癌旁组织的T-AOC含量则高于肝癌组织。结论:晚期肝癌组织中,体内抗氧化系统有显著改变。

人体肝癌和正常肝脏细胞内硒与氧化应激机制的初步探讨

目的 探讨微量元素硒和氧化应激水平在肝癌发展中的作用。方法 采集了数例肝癌晚期切除样品及其癌旁正常组织 ,测定了正常肝脏组织和癌组织不同细胞器中硒的含量以及超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GSH -Px)、硫氧还蛋白还原酶 (TrxR)活性及谷胱甘肽 (GSH)和蛋白总巯基的含量。结果 Se在肝癌溶酶体 (P <0 0 5 )、微粒体 (P <0 0 5 )、细胞质中的含量高于正常肝组织 ,几种抗氧化酶酶的活性和巯基含量均高于正常肝。癌细胞中的Se含量要明显高于相应的癌旁周围正常肝细胞 ,尤其是细胞核、线粒体和细胞质。癌细胞线粒体、细胞质中几种抗氧化酶的活性以及巯基含量均高于相应的癌旁正常肝细胞。结论 癌细胞代谢旺盛 ,摄取更多的营养物质 ,从而造成周围正常细胞营养素的缺乏 ,抗氧化能力的下降 。

吸烟相关喉鳞状细胞癌氧化应激机制的探讨

目的:分析吸烟相关喉鳞状细胞癌患者抗氧化酶类的表达情况,进一步探讨吸烟相关喉鳞状细胞癌的氧化应激机制。方法:连续收集2012-2015年收治的138例喉鳞状细胞癌患者和45例志愿者,根据吸烟指数和是否患病将其分为3组:A组(88例,重度吸烟喉鳞状细胞癌患者),B组(50例,不吸烟喉鳞状细胞癌患者),C组(45例,重度吸烟志愿者)。检测3组患者血清、癌组织及癌旁组织匀浆中过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)和NRF2的表达水平。结果:1A组中CAT、GSH-Px的表达水平显著低于B组(P<0.05),但高于C组(P<0.05);2A组MDA的水平显著高于B组(P<0.05)和C组(P<0.01);3喉鳞状细胞癌患者癌组织中NRF2普遍存在高表达,且其表达水平随着癌组织分化程度降低而升高(P<0.05)。结论:相比不吸烟患者,重度吸烟喉鳞状细胞癌患者将面临更加严重的氧化应激压力,喉鳞状细胞癌患者NRF2的表达水平与其病理分期有关。