Polycyclic aromatic hydrocarbon coated onto Fe2O3 particles: assessment ofcellular membrane damage and antioxidant system disruption in human epithelial lung cells (L132) in culture

The aim of this study was to investigate the oxidative effects of Fe2O3, be nzo(a)pyrene (B(a)P) and pyrene, alone or in association (B(a)P or pyrene c oated onto Fe2O3 particles), in normal human embryonic lung epithelial cell s (L132) in culture. We evaluated: (i) membrane integrity, through fatty ac id release (stearic acid, oleic acid, linoleic and linolenic acids, homolin olenic acid, arachidonic acid) and malondialdehyde (MDA) production; and (i i) antioxidant status, through enzymatic and non-enzymatic antioxidant defe nses (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione status, beta-carotene). Fe2O3 did not induce a ny change in L132 cells. In pyrene-treated cells, SOD induction (P < 0.05), glutathione oxidation (P < 0.05) and beta-carotene consumption (P < 0.001) may counteract free radicals (FR)-induced damage. However, in B(a)P-incuba ted cells, SOD inactivation (P ( 0.05), GR increases (P ( 0.05), glutathion e oxidation (P ( 0.05) and beta-carotene decreases (P < 0.001) showed high disruption of antioxidants, thereby allowing FR-induced damage (i.e. arachi donic acid release, P < 0.01; MDA production, P(0.01). Our main finding was that both associations caused higher FR-induced damage (i.e. MDA productio n. P < 0.001; SOD inactivation, P(0.01) than either chemical alone, Several mechanisms could account for this result: enhanced uptake of Fe2O3 particl es and/or greater availability of polycyclic aromatic hydrocarbons (PAHs). Wt hypothesized also that Fe2O3 and polycyclic aromatic hydrocarbons are mo re deleterious by virtue of their associations being able to produce higher oxidative effects than either chemical alone. (C) 2000 Elsevier Science Ir eland Ltd. All rights reserved.