The aryl hydrocarbon receptor (AhR) activity and DNA-damaging effects of chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs)

• Published in: Chemosphere (Oxford) Vol. 211; pp. 640 - 647
• Main Authors: Huang, Chao, Xu, Xiong, Wang, Donghong, Ma, Mei, Rao, Kaifeng, Wang, Zijian
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2018
• Subjects: Aryl hydrocarbon receptor (AhR); Chlorinated PAHs (Cl-PAHs); DNA Damage - genetics; DNA-Damaging effect; Environmental Pollutants - chemistry; Genotoxicity; Polycyclic Aromatic Hydrocarbons - chemistry; Receptors, Aryl Hydrocarbon - chemistry; DNA-Damaging effect; Aryl hydrocarbon receptor (AhR); Chlorinated PAHs (Cl-PAHs); Genotoxicity
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2018.07.087

An increasing number of studies have indicated that environmental contamination with chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) has been underestimated. However, insufficient available toxicological information on Cl-PAHs makes evaluating their risks to health challenging. Two in vitro bioassays were used in the present study to characterize the aryl hydrocarbon receptor (AhR) activity and DNA-damaging effects of 22 low-molecular-weight PAHs and their Cl-PAHs by using the EROD assay in rat hepatoma (H4IIE) cells and the SOS/umu test (S. typhimurium TA1535/pSK1002). Compared with their parent PAHs, most of the Cl-PAHs enhanced AhR-mediated activity in the EROD assay. 1,3,6,8-Tetrachloro-pyrene (1,3,6,8-Tetracl-Py) induced the greatest potency of EROD activity (83.1%-TCDD-max) and its single point ReP was 6.64 × 10−6. Compared with their parent PAHs, several Cl-PAHs showed significant DNA-damaging effects in the SOS/umu test with the addition of S9, and the toxic equivalency of benzo[a]pyrene (TEQBaP) was calculated for them. 9-Chloroanthracene (9-Ant) and 5,6-Dichloroacenaphthene (5,6-Dicl-Ace) had relatively high TEQBaP (0.62 and 0.54, respectively). However, only 1,3,6,8-Tetracl-Py elicited strong DNA-damaging effects in the absence of S9. The degree of chlorination, the position of chlorine substitutions, and the structure of parent PAHs influenced the potency of low-molecular-weight PAHs with regard to their AhR activity and DNA-damaging effects. More concern should be raised for these environmentally relevant pollutants. •Cl-PAHs had more potent AhR activity and DNA-damaging effects than their parent PAHs.•2,5-Dicl-Fl, 2,7-Dicl-Fl and 1,3,6,8-tetracl-Py induced strong EROD activity.•Degree of chlorination and the position of chlorine influence the AhR activity and DNA-damaging effects.