Exposure to selected limonene oxidation products: 4-oxopentanal (4-OPA), 3-isopropenyl-6-oxo-heptanal (IPOH), 4-acetyl-1-methylcyclohexene (4-AMCH) induce oxidative stress and inflammation in human lung epithelial cell lines

Limonene oxidation products (LOPs) have gained interest owing to multiple reports on harmful health effects. Recently, it has been shown that the selected LOPs: 4-OPA, IPOH and 4-AMCH have sensory irritation effects in mice and increased inflammatory markers in human lung cells. The present study was therefore undertaken to investigate the potential capacity of 4-OPA, IPOH and 4-AMCH to cause cell membrane damage (by lactate dehydrogenase assay), oxidative stress (by fluorescence assay and liquid chromatography) and inflammation (by enzyme-linked immunosorbent assay) in human alveolar (A549) and bronchial (16HBE14o-) epithelial cell lines. The overall results suggest that 4-OPA, IPOH have cytotoxic effects on human pulmonary cells, and that this might be mediated by ROS: the highest concentration applied of IPOH [500 µM] enhanced ROS generation by 100-fold (A549) and a 230-fold change (16HBE14o-) compared to the baseline. 4-OPA [500 µM] increased ROS levels by 1.4-fold ± 0.3 (A549) and by 127-fold ± 10.5 (16HBE14o-), while treatment with 4-AMCH [500 µM] led to a 0.9-fold ± 0.2 (A549) and 49-fold ± 12.8 (16HBE14o-) increase. IPOH [500 µM] caused a decrease in the thiol-state balance (e.g. 2 h post-treatment, GSH : GSSG ratio was significantly reduced by 37% compared with the untreated 16HBE14o- cells). 4-OPA [500 µM] decreased the GSH:GSSG ratio by a 1.3-fold change in A549 cells and a 1.4-fold change in 16HBE14o- cells. No statistically significant decrease in the GSH:GSSG ratio in both A549 and 16HBE14o- cell lines was observed at 500 µM 4-AMCH. In addition, both IPOH and 4-OPA [31.2 µM] increased the amount of the inflammatory markers: RANTES, VEGF and EGF (e.g. 2.0-fold change of RANTES amount determined in 16HBE14o- cells treated with IPOH [31.2 µM]). On the other hand, neither cell lines treated with 4-AMCH [31.2 µM] released statistically significant amounts of the selected inflammatory markers.JRC.F.2-Consumer Products Safet

Organochlorine levels in edible fish from the Marmara Sea, Turkey

Samples of 12 edible fish species from the Marmara Sea were analyzed for organochlorines (PCBs, DDTs, HCB, HCHs, toxaphene, etc.). The results showed that the total concentrations ranged from 329.41 ng/g fat to 1453.87 ng/g fat. DDT group components made up almost half or more of organochlorine contamination. Levels in red mullet were compared with those from neighbor seas. The sum of DDTs as well as HCHs concentrations were markedly lower than in the Black Sea but higher in the Aegean Sea and Mediterranean. Thus, inflow from the Black Sea might be considered as a contamination source for DDT and HCH contamination. On the other hand, total PCB concentration (sum of congeners 28, 52, 101, 118, 138, 153 and 180) detected in this study was comparable or lower than those from the Aegean Sea and Mediterranean. Toxaphene was a minor contaminant. Measured values were below maximum residue levels for human consumption. (c) 2006 Elsevier Ltd. All rights reserved

Inflammatory effects induced by selected limonene oxidation products: 4-OPA, IPOH, 4-AMCH in human bronchial (16HBE14o-) and alveolar (A549) epithelial cell lines

Limonene, a monoterpene abundantly present in most of the consumer products (due to its pleasant citrus smell), easily undergoes ozonolysis leading to several limonene oxidation products (LOPs) such as 4-acetyl-1-methylcyclohexene (4-AMCH), 4-oxopentanal (4-OPA) and 3-isopropenyl-6-oxoheptanal (IPOH). Toxicological studies have indicated that human exposure to limonene and ozone can cause adverse airway effects. However, little attention has been paid to the potential health impact of specific LOPs, in particular of IPOH, 4-OPA and 4-AMCH. This study evaluates the cytotoxic effects of the selected LOPs on human bronchial epithelial (16HBE14o-) and alveolar epithelial (A549) cell lines by generating concentration-response curves using the neutral red uptake assay and analyzing the inflammatory response with a series of cytokines/chemokines. The cellular viability was mostly reduced by 4-OPA [IC50=1.6 mM (A549) and 1.45 mM (16HBE14o-)] when compared to IPOH [IC50=3.5 mM (A549) and 3.4 mM (16HBE14o-)] and 4-AMCH [IC50 could not be calculated]. As a result from the inflammatory response, IPOH [50 µM] induced an increase of both IL-6 and IL-8 secretion in A549 (1.5-fold change) and in 16HBE14o- (2.8- and 7-fold change respectively). 4-OPA [50 µM] treatment of A549 increased IL-6 (1.4-times) and IL-8 (1.3-times) levels, while in 16HBE14o- had an opposite effect. A549 treated with 4-AMCH [50 µM] elevate both IL-6 and IL-8 levels by 1.2-times, while in 16HBE14o- had an opposite effect. Based on our results, lung cellular injury characterized by inflammatory cytokine release was observed for both cell lines treated with the selected chemicals at concentrations that did not affect their cellular viability.JRC.F.2-Consumer Products Safet