Urinary metabolic profiling of volatile organic compounds in acute exposed volunteers after an oil spill in Republic of Korea.

The Herbei Spirit oil spill occurred in western Korea. A large number of people who participated in the cleanup tasks of the contaminated area were exposed to crude oil component. We developed a method to monitor volatile organic compound (VOC) metabolites in urine, and evaluate the acute exposure caused by the oil spill in exposed volunteer workers (n = 100, 20.7 +/- 2.1 years, mean +/- SD). Acidified urine samples were extracted by SPE, derivatized with trimethylsilyl, and analyzed using gas chromatography-mass spectrometry. Calibration curves were found to be linear from 3 to 1000 ng/mL (r(2) > 0.993). Accuracy was over 82.4%, and precision was less than 24.8%. Using this method, the VOC metabolites, except hippuric acid, were present at higher levels in the urine samples of volunteers after cleanup work. The levels of mandelic acid (MA) and trans,trans-muconic acid (t,t-MU) were increased significantly (p < 0.001). The exposure effect was greater in women than in men. The effect of smoking was analyzed in all exposed and non-exposed groups, with non-smokers showing increased MA and t,t-MU levels related to exposure. The present method was reliable to determine VOC metabolites in urine and could be useful for biomonitoring of acute exposure effects of VOCs.

Antithrombotic effect of onion in streptozotocin-induced diabetic rat.

In the present study, we investigated whether onion has antithrombotic effect in streptozotocin (STZ)-induced diabetic rats. In diabetic rats, serum thromboxane B(2) (TXB(2)) level was elevated compared to that in normal, and this elevation in diabetes was significantly inhibited by treatment with onion (0.5 g/ml/kg/day, i.p.) for 4 weeks. In normal rats, the serum TXB(2) level remained unaltered after the treatment with onion. To investigate in vitro effect of onion, we examined its effect on TXB(2) formation, platelet aggregation and arachidonic acid (AA)-release in platelets from diabetic and normal rats. Onion showed a significant inhibitory effect on collagen- or AA-induced TXB(2) formation with greater potency in diabetic platelets than in normal. Similarly, more potent inhibitory effects of onion in diabetes were observed in collagen- or AA-induced platelet aggregation and collagen-induced AA release response. In conclusion, these results suggest that onion can produce more beneficial antithrombotic effect in diabetes.