title: Photodynamic action of benzo[a]pyrene in K562 cells.
abstract: Benzo[a]pyrene (BaP) is ubiquitously distributed in the environment, being considered the most phototoxic element among polycyclic aromatic hydrocarbon (PAHs). In presence of oxygen, PAHs can act as a photosensitizer by means of promoting photo-oxidation of biological molecules (photodynamic action, PDA). Thus, the present study analyzed the photodynamic action of BaP under UVA irradiation (BaP + UVA) and its oxidative effects on K562 cells. The evaluation of BaP kinetics showed that the highest intracellular concentration occurred after 18 h of incubation. Cell viability, reactive oxygen species (ROS) generation, lipid peroxidation, DNA damage (breaks and DNA-protein cross-link [DNAPC]) were assessed after exposure to BaP, UVA and BaP plus UVA irradiation (BaP + UVA). Cell viability was decreased just after exposure to BaP + UVA. Lipid peroxidation and DNA breaks increased after BaP + UVA exposure, while the DNAPC increased after BaP, UVA and BaP + UVA exposure, suggesting that BaP + UVA effects were a consequence of both type II (producing mainly singlet oxygen) and type I (producing others ROS) mechanisms of PDA.
authors.affiliation: Departamento de Ciências Fisiológicas, Fundação Universidade Federal do Rio Grande, Rio Grande, Brazil.
authors.forename: Daza de Moraes Vaz Batista
authors.initials: Dde M
authors.lastname: Filgueira
authors.forename: Diana Paula
authors.initials: DP
authors.lastname: Salomão de Freitas
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: de Souza Votto
authors.forename: Gilberto
authors.initials: G
authors.lastname: Fillmann
authors.forename: José Maria
authors.initials: JM
authors.lastname: Monserrat
authors.forename: Laura Alicia
authors.initials: LA
authors.lastname: Geracitano
authors.forename: Gilma
authors.initials: G
authors.lastname: Santos Trindade
mesh_terms: D001564:Benzo(a)pyrene / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D006801:Humans; D020014:K562 Cells; D007700:Kinetics; D010084:Oxidation-Reduction / Q000187:drug effects / Q000528:radiation effects; D018384:Oxidative Stress; D010777:Photochemistry; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism
chemical_list: D011506:Proteins; D001564:Benzo(a)pyrene; D004247:DNA