Effects of carcinogenic versus non-carcinogenic AHR-active PAHs and their mixtures: lessons from ecological relevance.
Environ Res
; 138: 101-11, 2015 Apr.
Article
em En
| MEDLINE
| ID: mdl-25704830
ABSTRACT
Polycyclic aromatic hydrocarbons (PAHs) are priority environmental mutagens and carcinogens that occur in the aquatic environment as mixtures rather than the individual compounds for which guidelines are issued. The present work aimed at understanding the interaction effects between carcinogenic and non-carcinogenic PAHs in a model marine fish (Dicentrarchus labrax) in realistic scenarios. Laboratory assays under ecologically-relevant parameters were conducted for 28 days with sediments spiked with low-moderate concentrations (250-800ngg(-1)) of two model PAHs, phenanthrene (non-carcinogenic) and benzo[b]fluoranthene (carcinogenic to experimental animals). Both PAHs induced hepatic histopathological changes that indicate metabolic failure and inflammation, especially in animals exposed to mixtures. Phenanthrene elicited biochemical changes better related to oxidative stress (lipid peroxidation, glutathione and glutathione S-transferase activity) and CYP function, whereas B[b]F disrupted metabolic responses and defences to toxicological challenge. Conversely, mixed PAHs yielded lesions and responses that, altogether, are compatible with the AHR dependent pathway (the basis of PAH mutagenicity), potentially generating supra-additive effects. Nonetheless, the low, ecologically-relevant, concentrations of PAHs diluted dose and time-response relations. Overall, although seemingly predicting the risk of individual PAHs, environmental guidelines may not apply to mixtures by underestimating adverse effects, which calls for a redefinition of standards when determining the true risk of toxicants under realistic circumstances.
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Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Fenantrenos
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Poluentes Químicos da Água
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Bass
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Carcinógenos
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Fluorenos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Environ Res
Ano de publicação:
2015
Tipo de documento:
Article