Effect of dietary treatment with n-propyl gallate or vitamin E on the survival of mice exposed to phosgene.
Phosgene, widely used in industrial processes, can cause life-threatening pulmonary edema and acute lung injury. One mechanism of protection against phosgene-induced lung injury may involve the use of antioxidants. The present study focused on dietary supplementation in mice using n-propyl gallate (nPG)--a gallate acid ester compound used in food preservation--and vitamin E. Five groups of male mice were studied: group 1, control-fed with Purina rodent chow 5002; group 2, fed 0.75% nPG (w/w) in 5002; group 3, fed 1.5% nPG (w/w) in 5002; group 4 fed 1% (w/w) vitamin E in 5002; and group 5, fed 2% (w/w) vitamin E also in 5002. Mice were fed for 23 days. On day 23 mice were exposed to 32 mg m-3 (8 ppm) phosgene for 20 min (640 mg. min m-3) in a whole-body exposure chamber. Survival rates were determined at 12 and 24 h. In mice that died within 12 h, the lungs were removed and lung wet weights, dry weights, wet/dry weight ratios, lipid peroxidation (thiobarbituric acid reactive substances, TBARS) and glutathione (GSH) were assessed. Vitamin E had no positive effect on any outcome measured. There was no significant difference between 1.5% nPG and any parameter measured or survival rate compared with 5002 + phosgene. However, dietary treatment with 0.75% nPG significantly increased survival rate (P </= 0.002) and lowered TBARS (P </= 0.05) compared with 5002 + phosgene at 12 h after exposure. Mice fed 0.75% nPG had a lower wet/dry wt ratio compared with those fed 1.5% nPG and a significantly increased lung tissue GSH 36%, compared with the 5002 + phosgene group. In conclusion, dietary treatment with a low level of the antioxidant nPG protected mice by decreasing lipid peroxidation and increasing lung tissue GSH. The higher level of nPG and both levels of vitamin E diets were ineffective, suggesting that a ceiling threshold level of antioxidants in lung tissue is required for survival against phosgene-induced lung injury. Published in 2001 by John Wiley & Sons, Ltd.
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US Army Medical Research Institute of Chemical Defense, Pharmacology Division, Neurotoxicology Branch, Aberdeen Proving Ground, MD 21010-5400, USA.
Moran
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D000280:Administration, Inhalation; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D004032:Diet; D005978:Glutathione / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D009929:Organ Size / Q000187:drug effects; D010705:Phosgene / Q000008:administration & dosage / Q000633:toxicity*; D011435:Propyl Gallate / Q000008:administration & dosage*; D011654:Pulmonary Edema / Q000139:chemically induced / Q000178:diet therapy* / Q000401:mortality / Q000517:prevention & control; D015996:Survival Rate; D013997:Time Factors; D014810:Vitamin E / Q000008:administration & dosage*
D000975:Antioxidants; D010705:Phosgene; D014810:Vitamin E; D011435:Propyl Gallate; D005978:Glutathione