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Dose-Response Assessment of Naphthalene-Induced Genotoxicity and Glutathione Detoxication in Human TK6 Lymphoblasts
- Source :
- Toxicological Sciences. 126:405-412
- Publication Year :
- 2012
- Publisher :
- Oxford University Press (OUP), 2012.
-
Abstract
- The dose-response relationship for the induction of micronuclei (MN) and the impact of glutathione (GSH) detoxication on naphthalene-induced cytotoxicity and genotoxicity were investigated in human TK6 cells. TK6 cells were exposed to 10 concentrations ranging from 0.0625 to 30μM naphthalene in the presence of β-naphthoflavone- and phenobarbital (βNP/PB)-induced rat liver S9 with a nicotinamide adenine dinucleotide phosphate-generating system. Three approaches were used to identify a no-observed-effect level (NOEL) for naphthalene-induced genotoxicity: (1) laboratory criteria of ≥ twofold increase over the concurrent solvent controls (NOEL = 10μM), (2) ANOVA with Bonferroni correction (NOEL = 2.5μM), and (3) the benchmark dose approach (BMCL(10) = 3.35μM). The NOEL and point of departure micronucleus frequency for naphthalene-induced MN are between the tested naphthalene concentrations of 2.5-10.0μM in this experimental system. Supplementation of the exposure system with physiological relevant concentrations of 5mM GSH eliminated naphthalene-induced cytotoxicity and genotoxicity; no increased cytotoxicity or genotoxicity was observed at concentrations of up to 500μM naphthalene in the presence of GSH compared with 2.5-10.0μM in the absence of GSH. Naphthalene bioactivation by βNP/PB-induced rat liver S9 exhibits a nonlinear dose-response for the induction of MN in TK6 cells with a NOEL of 2.5-10μM that in the presence of GSH is shifted upward greater than 50- to 200-fold. These data demonstrate a nonlinear dose-response for naphthalene-induced genotoxicity that is eliminated by GSH, and both observations should be considered when assessing human risk from naphthalene exposures.
- Subjects :
- Naphthalenes
Nicotinamide adenine dinucleotide
Pharmacology
Toxicology
medicine.disease_cause
Cell Line
chemistry.chemical_compound
medicine
Animals
Humans
Lymphocytes
Cytotoxicity
Biotransformation
Micronucleus Tests
Dose-Response Relationship, Drug
Chemistry
Lymphoblast
Glutathione
Rats
Biochemistry
Micronucleus test
Phenobarbital
Micronucleus
Genotoxicity
Mutagens
medicine.drug
Subjects
Details
- ISSN :
- 10960929 and 10966080
- Volume :
- 126
- Database :
- OpenAIRE
- Journal :
- Toxicological Sciences
- Accession number :
- edsair.doi.dedup.....344f60b3b891db67f731098f37130275