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St. John's wort ( Hypericum perforatum ) counteracts cytokine-induced tryptophan catabolism in vitro

St. John's wort ( Hypericum perforatum ) counteracts cytokine-induced tryptophan catabolism in vitro Abstract St. John's wort ( Hypericum perforatum) is an ancient folk remedy that has antiviral and antibacterial properties. Anti-inflammatory effects of the plant have been described and the application of H. perforatum extract as an effective antidepressant is well established. In this study we assayed the effect of H. perforatum extract on cytokine-induced tryptophan degradation in human peripheral blood mononuclear cells. Simultaneously, changes in the production of the immune activation marker neopterin were monitored. Both these biochemical pathways are triggered by interferon-γ. Our results show that extracts of H. perforatum strongly down-regulate mitogen-mediated tryptophan degradation in a dose-dependent manner. This effect seems to be based on a suppressive activity of H. perforatum on activated immunocompetent cells, resulting in a diminished production of interferon-γ. In line with this finding, neopterin synthesis was strongly down-regulated by the plant extract. Our results suggest that the reduction of tryptophan degradation by H. perforatum might be important in the action of the plant as an antidepressant. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Biological Chemistry de Gruyter

St. John's wort ( Hypericum perforatum ) counteracts cytokine-induced tryptophan catabolism in vitro

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References (36)

Publisher
de Gruyter
Copyright
Copyright © 2004 by the
ISSN
1431-6730
eISSN
1437-4315
DOI
10.1515/BC.2004.155
pmid
15653434
Publisher site
See Article on Publisher Site

Abstract

Abstract St. John's wort ( Hypericum perforatum) is an ancient folk remedy that has antiviral and antibacterial properties. Anti-inflammatory effects of the plant have been described and the application of H. perforatum extract as an effective antidepressant is well established. In this study we assayed the effect of H. perforatum extract on cytokine-induced tryptophan degradation in human peripheral blood mononuclear cells. Simultaneously, changes in the production of the immune activation marker neopterin were monitored. Both these biochemical pathways are triggered by interferon-γ. Our results show that extracts of H. perforatum strongly down-regulate mitogen-mediated tryptophan degradation in a dose-dependent manner. This effect seems to be based on a suppressive activity of H. perforatum on activated immunocompetent cells, resulting in a diminished production of interferon-γ. In line with this finding, neopterin synthesis was strongly down-regulated by the plant extract. Our results suggest that the reduction of tryptophan degradation by H. perforatum might be important in the action of the plant as an antidepressant.

Journal

Biological Chemistryde Gruyter

Published: Dec 1, 2004

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