title: Effects of different sources and levels of zinc on H2O2-induced apoptosis in IEC-6 cells.
abstract: Zinc has been shown to be an inhibitor of apoptosis for many years. The present study was designed to investigate effects of three zinc chemical forms on H2O2-induced cell apoptosis in IEC-6 cells via analysis of cell vitality, LDH activity, apoptosis percentage, caspase-3 activity, and Bcl-2, Bax, and caspase-3, -8, and -9 gene expression. Cells were divided into H2O2 and zinc sources+H2O2 groups, and there are three different zinc sources [zinc oxide nanoparticle (nano-ZnO), zinc oxide (ZnO), and zinc sulfate (ZnSO4)] and three concentrations (normal = 25 μM, medium = 50 μM, and high = 100 μM) used in this article. In the present study, we found the striking cytotoxicity of H2O2 higher than 200 μM on cell vitality, LDH activity, and apoptosis percentage in the cells using five different concentrations (50, 100, 200, 400, and 800 μM) of H2O2 for 4 h. Moreover, we observed that cell vitality was increased, LDH activity and apoptotic percentage were decreased, and gene expression level of Bax and caspase-3 and -9 was markedly reduced, while gene expression level of Bcl-2 and ratio of Bcl-2/Bax were increased in normal concentration groups of nano-ZnO and ZnSO4 compared with H2O2 group, but no significant difference was observed in caspase-8 gene expression. Furthermore, medium or, more intensely, high concentrations of nano-ZnO and ZnSO4 enhanced H2O2-induced cell apoptosis. Compared with nano-ZnO and ZnSO4, ZnO showed weakest protective effect on H2O2-induced apoptosis at normal concentration and was less toxic to cells at high level. Taken together, we proposed that preventive and protective effects of zinc on H2O2-induced cell apoptosis varied in IEC-6 cells with its chemical forms and concentrations, and maybe for the first time, we suggested that nano-ZnO have a protective effect on H2O2-induced cell apoptosis in IEC-6 cells.
authors.affiliation: Institute of Animal Nutrition, Key Laboratory of Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Ya' an, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Mao
authors.forename: Juncai
authors.initials: J
authors.lastname: Chen
authors.forename: Quanhui
authors.initials: Q
authors.lastname: Peng
authors.forename: Aiming
authors.initials: A
authors.lastname: Zhou
authors.forename: Zhisheng
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053181:Caspase 8 / Q000235:genetics; D053453:Caspase 9 / Q000235:genetics; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007422:Intestines / Q000166:cytology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D053758:Nanoparticles; D016877:Oxidants / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015034:Zinc Oxide / Q000494:pharmacology*; D019287:Zinc Sulfate / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein / Q000235:genetics
chemical_list: D016877:Oxidants; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D019287:Zinc Sulfate; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D015034:Zinc Oxide