Study on activation of benzo(a)pyrene and DNA damage mediated by lipoxygenase in human bronchial epithelial cells / 中华劳动卫生职业病杂志
Chinese Journal of Industrial Hygiene and Occupational Diseases
;
(12): 641-648, 2013.
Article
in Chinese
| WPRIM
| ID: wpr-275865
ABSTRACT
<p><b>OBJECTIVE</b>The oxidation of benzo (a) pyrene mediated by 5-lipoxygenase (5-LOX) were investigated in HBE cells in order to provide further proof that lipoxygenase is the alternative pathway for the oxidation of xenobiotics.</p><p><b>METHODS</b>Enzymic experiment Soybean lipoxygenase (SLO), substrate (benzo[a] pyrene) and other component react in the enzymic system and the reaction product are detected by spectrophotometry. At the same time, in vitro detect of benzo (a) pyrene-DNA adducts with a UV spectrophotometer and HPLC. Cellular experiment After HBE cells exposure to different poison (B[a]P 4, 8, 16, 32, 64, 128µmol/L, AA-861, naproxen or α- naphthoflavone 0.1, 1, 10 µmol/L) for 24 hours, the effect of benzo (a) -pyrene on cell survival rate were assessed by reductions of tetrazolium dye (MTT) and flow cytometry in cultured HBE cells, and the protein expressions of 5-lipoxygenase in the cells are tested by western-blot, and the DNA damages by the single cell gel electrophoresis. And then, the effect of the specific inhibitor of 5-lipoxygenase (AA-861) on 5-lipoxygenase protein expression and DNA damage in the cells are detected.</p><p><b>RESULTS</b>SLO can catalyze the co-oxidation of benzo (a) pyrene to generate benzo (a) pyrene-7,8-epoxide in the presence of hydrogen peroxide. GTP can inhibit the reaction , the IC50 value is 0.46 mg/L, the model equation is Probit (P) = 0.8985+2.6824 Log (dose). SLO can catalyze the co-oxidation of benzo (a) pyrene to generate a new product, but fail to form DNA adducts in vitro. HBE cell viability decreased with the benzo (a) pyrene concentration increased , but AA-861 and naproxen can inhibit it. Flow cytometry and single cell gel electrophoresis experiments show, Benzo (a) pyrene can induce 5-lipoxygenase protein expression, but AA-861 cannot in HBE. Benzo (a) pyrene causes toxic action and DNA damage in HBE, which can significantly inhibit by AA-861, the difference is statistically significant (P < 0.05).</p><p><b>CONCLUSIONS</b>The co-oxidate of benzo (a) pyrene by 5-LOX turns into electrophiles that covalently bind to DNA and induce DNA damage, which can be significantly inhibited by AA-861.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Pharmacology
/
Benzo(a)pyrene
/
DNA Damage
/
Cells, Cultured
/
Lipoxygenase
/
DNA Adducts
/
Epithelial Cells
/
Metabolism
Limits:
Humans
Language:
Chinese
Journal:
Chinese Journal of Industrial Hygiene and Occupational Diseases
Year:
2013
Type:
Article
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