title: Cacao extracts suppress tryptophan degradation of mitogen-stimulated  peripheral blood mononuclear cells.
abstract: BACKGROUND
  The fruits of Theobroma cacao L. (Sterculiaceae) have been used as food and a remedy for more than 4000 years. Today, about 100 therapeutic applications of cacao are described involving the gastrointestinal, nervous, cardiovascular and immune systems. Pro-inflammatory cytokine interferon-gamma and related biochemical pathways like tryptophan degradation by indoleamine 2,3-dioxygenase and neopterin formation are closely associated with the pathogenesis of such disorders.
  
  
  OBJECTIVE
  To determine the anti-inflammatory effect of cacao extracts on interferon-gamma and biochemical consequences in immunocompetent cells.
  
  
  METHODS
  Effects of aqueous or ethanolic extracts of cacao were examined on mitogen-induced human peripheral blood mononuclear cells (PBMC) of healthy donors and on lipopolysaccharide-stimulated myelomonocytic THP-1 cells. Antioxidant activity of extracts was determined by oxygen radical absorption capacity (ORAC) assay.
  
  
  RESULTS
  In mitogen-stimulated PBMC, enhanced degradation of tryptophan, formation of neopterin and interferon-gamma were almost completely suppressed by the cacao extracts at doses of > or = 5 microg/mL. Cacao extracts had no effect on tryptophan degradation in lipopolysaccharide-stimulated THP-1 cells.
  
  
  CONCLUSIONS
  There is a significant suppressive effect of cacao extracts on pro-inflammatory pathways in activated T-cells. Particularly the influence on indoleamine 2,3-dioxygenase could relate to some of the beneficial health effects ascribed to cacao.
authors.affiliation: Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Fritz-Pregl-Str. 3, 6020 Innsbruck, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Jenny
authors.forename: E
authors.initials: E
authors.lastname: Santer
authors.forename: A
authors.initials: A
authors.lastname: Klein
authors.forename: M
authors.initials: M
authors.lastname: Ledochowski
authors.forename: H
authors.initials: H
authors.lastname: Schennach
authors.forename: F
authors.initials: F
authors.lastname: Ueberall
authors.forename: D
authors.initials: D
authors.lastname: Fuchs