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Molecular and cellular influences of butylated hydroxyanisole on Chinese hamster V79 cells treated with N ‐methyl‐ N ′‐nitro‐ N ‐nitrosoguanidine: Antimutagenicity of butylated hydroxyanisole
Author(s) -
Slameňová Darina,
Horváthová Eva,
Robichová Soňa,
Hrušovská L'ubica,
Gábelová Alena,
Kleibl Karol,
Jakubíková Jana,
Sedlák Ján
Publication year - 2003
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.10127
Subject(s) - butylated hydroxyanisole , methylnitronitrosoguanidine , chinese hamster , carcinogen , biochemistry , chemistry , mutagen , microbiology and biotechnology , cytotoxicity , hamster , butylated hydroxytoluene , dna damage , 2 acetylaminofluorene , dna , mutagenesis , antioxidant , mutant , biology , enzyme , in vitro , microsome , gene
The antioxidant butylated hydroxyanisole (BHA) is a rodent carcinogen that also reduces the mutagenicity and carcinogenicity of other agents. In this study, we have evaluated possible mechanisms for the antimutagenicity of BHA by investigating its effects on N ‐methyl‐ N′ ‐nitro‐ N ‐nitrosoguanidine (MNNG)‐treated Chinese hamster V79 cells. Mutant frequency was determined using the hprt /V79 assay, while plating efficiency was used to measure cytotoxicity, and apoptosis was measured by flow immunofluorocytometry. In addition, DNA strand breaks and the kinetics of strand‐break rejoining were investigated by the alkaline elution of DNA and by single‐cell gel electrophoresis (SCGE). Although the higher concentration of BHA (0.5 mM) increased the cytotoxicity of MNNG and the lower concentration of BHA (0.25 mM) did not change it, both concentrations were antimutagenic in MNNG‐treated cells, with the greater effect occurring at the lower BHA concentration. Neither BHA nor MNNG nor BHA + MNNG increased the level of apoptotic nuclei, and BHA did not change the level of MNNG‐induced DNA strand breaks, though it did inhibit their rejoining. Determination of O 6 ‐methylguanine‐DNA‐methyltransferase (MGMT) activity confirmed that V79 cells do not synthesize active MGMT protein; MGMT activity was also undetectable after MNNG and BHA + MNNG treatment. The ability of BHA to reduce the level of MNNG‐induced mutations did not correlate with cytotoxicity, induction of apoptosis, the level of DNA strand break induction, or MGMT activity. A modified SCGE assay showed that BHA significantly reduced the level of formamidopyrimidine‐DNA‐glycosylase + endonucleaseIII‐sensitive sites, which at least partially are caused by oxidative DNA lesions. The results suggest that the protective effect of BHA on MNNG‐induced mutagenicity is best explained by the antioxidative activity of BHA, which may scavenge free radicals that participate in MNNG‐induced mutagenicity. Environ. Mol. Mutagen. 41:28–36, 2003. © 2003 Wiley‐Liss, Inc.