Cacao extracts suppress tryptophan degradation of mitogen-stimulated peripheral blood mononuclear cells

J Ethnopharmacol. 2009 Mar 18;122(2):261-7. doi: 10.1016/j.jep.2009.01.011.


Ethnopharmacological relevance: 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.

Aim of the study: To determine the anti-inflammatory effect of cacao extracts on interferon-gamma and biochemical consequences in immunocompetent cells.

Materials and 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Inflammatory Agents / pharmacology*
  • Antioxidants / pharmacology*
  • Cacao* / chemistry
  • Cells, Cultured
  • Humans
  • Interferon-gamma / antagonists & inhibitors*
  • Kynurenine / metabolism
  • Leukocytes, Mononuclear
  • Lipopolysaccharides
  • Mitogens
  • Neopterin / antagonists & inhibitors*
  • Phytohemagglutinins / pharmacology
  • Plant Extracts / pharmacology*
  • Seeds
  • Th1 Cells / metabolism
  • Tryptophan / metabolism*


  • Anti-Inflammatory Agents
  • Antioxidants
  • Lipopolysaccharides
  • Mitogens
  • Phytohemagglutinins
  • Plant Extracts
  • Kynurenine
  • Neopterin
  • Interferon-gamma
  • Tryptophan