Gamma-tocopherol supplementation inhibits protein nitration and ascorbate oxidation in rats with inflammation

Jiang, Q; Lykkesfeldt, J; Shigenaga, MK; Shigeno, ET; Christen, S; Ames, BN (2002). Gamma-tocopherol supplementation inhibits protein nitration and ascorbate oxidation in rats with inflammation. Free radical biology & medicine, 33(11), pp. 1534-42. San Diego, Calif.: Elsevier 10.1016/S0891-5849(02)01091-2

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Gamma-tocopherol (gammaT) complements alpha-tocopherol (alphaT) by trapping reactive nitrogen oxides to form a stable adduct, 5-nitro-gammaT [Christen et al., PNAS 94:3217-3222; 1997]. This observation led to the current investigation in which we studied the effects of gammaT supplementation on plasma and tissue vitamin C, vitamin E, and protein nitration before and after zymosan-induced acute peritonitis. Male Fischer 344 rats were fed for 4 weeks with either a normal chow diet with basal 32 mg alphaT/kg, or the same diet supplemented with approximately 90 mg d-gammaT/kg. Supplementation resulted in significantly higher levels of gammaT in plasma, liver, and kidney of control animals without affecting alphaT, total alphaT+gammaT or vitamin C. Intraperitoneal injection of zymosan caused a marked increase in 3-nitrotyrosine and a profound decline in vitamin C in all tissues examined. Supplementation with gammaT significantly inhibited protein nitration and ascorbate oxidation in the kidney, as indicated by the 29% and 56% reduction of kidney 3-nitrotyrosine and dehydroascorbate, respectively. Supplementation significantly attenuated inflammation-induced loss of vitamin C in the plasma (38%) and kidney (20%). Zymosan-treated animals had significantly higher plasma and tissue gammaT than nontreated pair-fed controls, and the elevation of gammaT was strongly accentuated by the supplementation. In contrast, alphaT did not significantly change in response to zymosan treatment. In untreated control animals, gammaT supplementation lowered basal levels of 3-nitrotyrosine in the kidney and buffered the starvation-induced changes in vitamin C in all tissues examined. Our study provides the first in vivo evidence that in rats with high basal amounts of alphaT, a moderate gammaT supplementation attenuates inflammation-mediated damage, and spares vitamin C during starvation-induced stress without affecting alphaT.

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Service Sector > Institute for Infectious Diseases
UniBE Contributor:	Christen, Stephan
ISSN:	0891-5849
ISBN:	12446211
Publisher:	Elsevier
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:56
Last Modified:	05 Dec 2022 14:17
Publisher DOI:	10.1016/S0891-5849(02)01091-2
PubMed ID:	12446211
Web of Science ID:	000179434500012
URI:	https://boris.unibe.ch/id/eprint/23687 (FactScience: 43478)