caa a22 4500 378895990 CHVBK 20180305123506.0 cr unu---uuuuu 161128e20041201xx s 000 0 eng 10.1515/BC.2004.155 doi (NATIONALLICENCE)gruyter-10.1515/BC.2004.155 St. John's wort (Hypericum perforatum) counteracts cytokine-induced tryptophan catabolism in vitro [Elektronische Daten] [Christiana Winkler, Barbara Wirleitner, Katharina Schroecksnadel, Harald Schennach, Dietmar Fuchs] 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. ©2004 by Walter de Gruyter Berlin New York Biochemistry nationallicence Molecular biology nationallicence Cellular biology nationallicence Hypericum perforatum nationallicence immune activation nationallicence indoleamine (2,3)-dioxygenase nationallicence neopterin nationallicence St. John's wort nationallicence tryptophan nationallicence Winkler Christiana Institute of Medical Chemistry and Biochemistry, Innsbruck Medical University, A-6020 Innsbruck, Austria aut Wirleitner Barbara Institute of Medical Chemistry and Biochemistry, Innsbruck Medical University, A-6020 Innsbruck, Austria aut Schroecksnadel Katharina Institute of Medical Chemistry and Biochemistry, Innsbruck Medical University, A-6020 Innsbruck, Austria aut Schennach Harald Central Institute of Blood Transfusion and Immunology, University Hospital Innsbruck, A-6020 Innsbruck, Austria aut Fuchs Dietmar Institute of Medical Chemistry and Biochemistry, Innsbruck Medical University, A-6020 Innsbruck, Austria and Ludwig Boltzmann Institute of AIDS-Research, A-6020 Innsbruck, Austria aut Biological Chemistry Walter de Gruyter 385/12(2004-12-01), 1197-1202 1431-6730 385:12<1197 2004 385 bchm https://doi.org/10.1515/BC.2004.155 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/BC.2004.155 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Winkler Christiana Institute of Medical Chemistry and Biochemistry, Innsbruck Medical University, A-6020 Innsbruck, Austria aut NATIONALLICENCE 700 1- Wirleitner Barbara Institute of Medical Chemistry and Biochemistry, Innsbruck Medical University, A-6020 Innsbruck, Austria aut NATIONALLICENCE 700 1- Schroecksnadel Katharina Institute of Medical Chemistry and Biochemistry, Innsbruck Medical University, A-6020 Innsbruck, Austria aut NATIONALLICENCE 700 1- Schennach Harald Central Institute of Blood Transfusion and Immunology, University Hospital Innsbruck, A-6020 Innsbruck, Austria aut NATIONALLICENCE 700 1- Fuchs Dietmar Institute of Medical Chemistry and Biochemistry, Innsbruck Medical University, A-6020 Innsbruck, Austria and Ludwig Boltzmann Institute of AIDS-Research, A-6020 Innsbruck, Austria aut NATIONALLICENCE 773 0- Biological Chemistry Walter de Gruyter 385/12(2004-12-01), 1197-1202 1431-6730 385:12<1197 2004 385 bchm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter