Cytotoxic and genotoxic effects of tert-butyl hydroperoxide on Chinese hamster B14 cells.
The organic hydroperoxide, tert-butyl hydroperoxide (t-BHP), is a useful model compound to study mechanisms of oxidative cell injury. In the present work, we examined the features of the interactions of this oxidant with Chinese hamster B14 cells. The aim of our study was to reveal a possible role of structural modifications in membranes and loss of DNA integrity in t-BHP-induced cell injury and death. The tert-butyl hydroperoxide treatment (100-1000 microM, 37 degrees C for 1h) did not decrease cell viability (as measured by cell-specific functional activity with an MTT test), but completely prevented cell growth. We observed intracellular reduced glutathione (GSH) oxidation and total glutathione (GSH+GSSG) depletion, a slight increase in the level of lipid-peroxidation products, an enhancement of membrane fluidity, intracellular potassium leakage and a significant decrease of membrane potential. At oxidant concentrations of 100-1500 microM, a significant damage to DNA integrity was observed as revealed by the Comet assay. The inhibition of cell proliferation (cell-growth arrest) may be explained by genotoxicity of t-BHP, by disturbance of the cellular redox-equilibrium (GSH oxidation) and by structural membrane modifications, which result in ion-non-selective pore formation. The disturbance in passive membrane permeability and the DNA damage may be the most dramatic cell impairments induced by t-BHP treatment. The presence of another oxidant, hypochlorous acid (HOCl), completely prevented t-BHP-induced DNA strand breaks, perhaps due to extracellular oxidation of t-BHP by HOCl.
Lapshina
Elena A
EA
Institute of Biochemistry, National Academy of Sciences of Belarus, BLK-50, 230017 Grodno, Belarus.
Zavodnik
Ilya B
IB
Labieniec
Magdalena
M
Rekawiecka
Katarzyna
K
Bryszewska
Maria
M
D000704:Analysis of Variance; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D020552:Comet Assay; D006224:Cricetinae; D003412:Cricetulus; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D005454:Fluorescence Polarization; D005978:Glutathione / Q000378:metabolism; D006997:Hypochlorous Acid / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D011188:Potassium / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles; D017392:Thiobarbituric Acid Reactive Substances; D020122:tert-Butylhydroperoxide / Q000378:metabolism / Q000633:toxicity*
D013778:Tetrazolium Salts; D013844:Thiazoles; D017392:Thiobarbituric Acid Reactive Substances; D006997:Hypochlorous Acid; D020122:tert-Butylhydroperoxide; C022616:thiazolyl blue; D005978:Glutathione; D011188:Potassium