Photodynamic action of benzo[a]pyrene in K562 cells

Photochem Photobiol. 2007 Nov-Dec;83(6):1358-63. doi: 10.1111/j.1751-1097.2007.00169.x.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzo(a)pyrene / pharmacology*
  • Cell Survival / drug effects
  • Cell Survival / radiation effects
  • DNA / metabolism
  • DNA Damage
  • Humans
  • K562 Cells
  • Kinetics
  • Oxidation-Reduction / drug effects
  • Oxidation-Reduction / radiation effects
  • Oxidative Stress
  • Photochemistry
  • Protein Binding
  • Proteins / metabolism

Substances

  • Proteins
  • Benzo(a)pyrene
  • DNA