Antioxidant activities of some tryptophan metabolites: possible implication for inflammatory diseases

Christen, S; Peterhans, E; Stocker, R (1990). Antioxidant activities of some tryptophan metabolites: possible implication for inflammatory diseases. Proceedings of the National Academy of Sciences of the United States of America - PNAS, 87(7), pp. 2506-10. Washington, D.C.: National Academy of Sciences NAS 10.1073/pnas.87.7.2506

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The antioxidant properties of tryptophan and some of its oxidative metabolites were examined by measuring how efficiently they inhibited peroxyl radical-mediated oxidation of phosphatidylcholine liposomes and B-phycoerythrin. Low micromolar concentrations of 5-hydroxytryptophan, 3-hydroxykynurenine, xanthurenic acid, or 3-hydroxyanthranilic acid, but not their corresponding nonhydroxylated metabolic precursors, scavenged peroxyl radicals with high efficiency. In particular, 3-hydroxykynurenine and 3-hydroxyanthranilic acid protected B-phycoerythrin from peroxyl radical-mediated oxidative damage more effectively than equimolar amounts of either ascorbate or Trolox (a water-soluble analog of vitamin E). Enzyme activities involved or related to oxidative tryptophan metabolism, as well as endogenous concentrations of tryptophan and its metabolites, were determined within tissues of mice suffering from acute viral pneumonia. Infection resulted in a 100-fold induction of pulmonary indoleamine 2,3-dioxygenase (EC 1.13.11.17) as reported [Yoshida, R., Urade, Y., Tokuda, M. ; Hayaishi, O. (1979) Proc. Natl. Acad. Sci. USA 76, 4084-4086]. This was accompanied by a 16- and 3-fold increase in the levels of lung kynurenine and 3-hydroxykynurenine, respectively. In contrast, endogenous concentrations of tryptophan and xanthurenic acid did not increase and 3-hydroxyanthranilic acid could not be detected. The activity of the superoxide anion (O2-.)-producing enzyme xanthine oxidase increased 3.5-fold during infection while that of the O2-.-removing superoxide dismutase decreased to 50% of control levels. These results plus the known requirement of indoleamine 2,3-dioxygenase for superoxide anion for catalytic activity suggest that viral pneumonia is accompanied by oxidative stress and that induction of indoleamine 2,3-dioxygenase may represent a local antioxidant defence against this and possibly other types of inflammatory diseases.

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Service Sector > Institute for Infectious Diseases
UniBE Contributor:	Christen, Stephan
ISSN:	0027-8424
ISBN:	2320571
Publisher:	National Academy of Sciences NAS
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:56
Last Modified:	05 Dec 2022 14:17
Publisher DOI:	10.1073/pnas.87.7.2506
PubMed ID:	2320571
Web of Science ID:	A1990CX49700026
URI:	https://boris.unibe.ch/id/eprint/23704 (FactScience: 43513)