title: Cytoprotective effect of trolox against oxidative damage and apoptosis in the NRK-52e cells induced by melamine.
abstract: An outbreak of urinary stones associated with consumption of melamine-tainted milk products occurred in 2008 in China, leading to serious illness of many infants and even death. However, the toxicity of melamine in kidney epithelial cells remains unclear. We have explored the effects of melamine and trolox on renal NRK-52e (normal rat kidney 52e) cells. The IC(50) of melamine was measured by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay. Total SOD (superoxide dismutase) was determined by NBT (Nitro Blue Tetrazolium) staining method. GSH-Px (glutathione peroxidase) activity was detected by UV colorimetric assay, and MDA (malondialdehyde) content was determined by thiobarbituric acid assay. Apoptosis induced by melamine was determined by flow cytometry. The IC(50) increased when NRK-52e cells were treated with both melamine and trolox compared with melamine only. SOD and GSH-Px activities were decreased, but MDA content was increased by melamine in a dose-dependent manner. Trolox significantly enhanced SOD and GSH-Px activity in melamine-treated NRK-52e cells, but it decreased their MDA content. LDH (lactate dehydrogenase) activity and the level of ROS (reactive oxygen species) of the NRK-52e cells were enhanced by melamine compared with the control. Furthermore, the apoptosis rate increased in NRK-52e cells treated with melamine, whereas trolox was protective. These results show that melamine has an obvious adverse effect on proliferation of NRK-52e cells, causing oxidative damage and apoptosis, thus providing a novel insight into renal cytotoxicology of melamine. Trolox ameliorates the effect on melamine toxicity.
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha, Peoples Republic of China.
authors.forename: Chengzhi
authors.initials: C
authors.lastname: Guo
authors.forename: Zuping
authors.initials: Z
authors.lastname: He
authors.forename: Lixin
authors.initials: L
authors.lastname: Wen
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.forename: Yin
authors.initials: Y
authors.lastname: Lu
authors.forename: Sijun
authors.initials: S
authors.lastname: Deng
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wei
authors.forename: Hui
authors.initials: H
authors.lastname: Yuan
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D002839:Chromans / Q000494:pharmacology*; D019610:Cytoprotection / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014227:Triazines / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D002839:Chromans; D017382:Reactive Oxygen Species; D014227:Triazines; D008315:Malondialdehyde; D007770:L-Lactate Dehydrogenase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; C011907:melamine; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid