Genotoxicity and DNA damage signaling in response to complex mixtures of PAHs in biomass burning particulate matter from cashew nut roasting.
Environ Pollut
; 256: 113381, 2020 Jan.
Article
en En
| MEDLINE
| ID: mdl-31662259
ABSTRACT
Approximately 3 billion people world-wide are exposed to air pollution from biomass burning. Herein, particulate matter (PM) emitted from artisanal cashew nut roasting, an important economic activity worldwide, was investigated. This study focused on i) chemical characterization of polycyclic aromatic hydrocarbons (PAHs) and oxygenated (oxy-) PAHs; ii) intracellular levels of reactive oxygen species (ROS); iii) genotoxic effects and time- and dose-dependent activation of DNA damage signaling, and iv) differential expression of genes involved in xenobiotic metabolism, inflammation, cell cycle arrest and DNA repair, using A549 lung cells. Among the PAHs, chrysene, benzo[a]pyrene (B[a]P), benzo[b]fluoranthene, and benz[a]anthracene showed the highest concentrations (7.8-10â¯ng/m3), while benzanthrone and 9,10-anthraquinone were the most abundant oxy-PAHs. Testing of PM extracts was based on B[a]P equivalent doses (B[a]Peq). IC50 values for viability were 5.7 and 3.0â¯nMâ¯B[a]Peq at 24â¯h and 48â¯h, respectively. At these low doses, we observed a time- and dose-dependent increase in intracellular levels of ROS, genotoxicity (DNA strand breaks) and DNA damage signaling (phosphorylation of the protein checkpoint kinase 1 - Chk1). In comparison, effects of B[a]P alone was observed at micromolar range. To our knowledge, no previous study has demonstrated an activation of pChk1, a biomarker used to estimate the carcinogenic potency of PAHs in vitro, in lung cells exposed to cashew nut roasting extracts. Sustained induction of expression of several important stress response mediators of xenobiotic metabolism (CYP1A1, CYP1B1), ROS and pro-inflammatory response (IL-8, TNF-α, IL-2, COX2), and DNA damage response (CDKN1A and DDB2) was also identified. In conclusion, our data show high potency of cashew nut roasting PM to induce cellular stress including genotoxicity, and more potently when compared to B[a]P alone. Our study provides new data that will help elucidate the toxic effects of low-levels of PAH mixtures from air PM generated by cashew nut roasting.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Hidrocarburos Policíclicos Aromáticos
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Daño del ADN
/
Anacardium
/
Contaminantes Atmosféricos
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Material Particulado
/
Nueces
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Environ Pollut
Asunto de la revista:
SAUDE AMBIENTAL
Año:
2020
Tipo del documento:
Article