Nitrated Polycyclic Aromatic Hydrocarbons and Arachidonic Acid Metabolisms Relevant to Cardiovascular Pathophysiology: Findings from a Panel Study in Healthy Adults

Concerns on nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) in the environment have mainly arisen from their mutagenic and carcinogenic effects. The objective of this study is to investigate whether nitro-PAH exposures are associated with biomarkers of cardiovascular pathophysiology. In a panel study design, urines and blood samples were collected up to four times with a 2-week interval from 89 healthy adults. We measured 1-naphthylamine, 2-naphthylamine, 9-aminophenanthrene, 2-aminofluorene, and 1-aminopyrene as biomarkers of nitro-PAH exposures. We measured three urinary metabolites of arachidonic acid (AA) including 20-hydroxyeicosatetraenoic acid (20-HETE) from the cytochrome P450 (CYP) pathway, 8-isoprostane from the nonenzymatic pathway, and 11-dehydro-thromboxane B2 (11-dhTXB2) from the cyclooxygenase (COX) pathway. Urinary malondialdehyde, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and 6-sulfatoxymelatonin (aMT6s) were measured to reflect systemic oxidative stress. Plasma concentrations of the soluble P-selectin and von Willebrand factor (vWF) were measured as biomarkers of platelet activation and endothelial dysfunction. We found that increased urinary concentrations of amino-PAHs were significantly associated with increased 20-HETE, 11-dhTXB2, and 8-OHdG and with decreased 8-isoprostane and aMT6s. Increased amino-PAHs were positively associated with P-selectin and vWF, respectively. These results suggest that exposure to nitro-PAHs increases systemic oxidative stress and alters AA metabolism toward CYP and COX pathways, leading to an increased cardiovascular disease risk.