Immunomodulatory properties of cacao extracts – potential consequences for medical applications

Abstract

Anti-inflammatory properties of cacao, fruits of Theobroma cacao L. (Sterculiaceae), are well documented, and therapeutic applications are described for gastrointestinal, nervous, and cardiovascular abnormalities. Most, if not all of these disease conditions involve inflammation or immune activation processes. The pro-inflammatory cytokine interferon-γ (IFN-γ) and related biochemical pathways like tryptophan breakdown by indoleamine 2,3-dioxygenase (IDO) and neopterin formation are deeply involved in their pathogenesis. Neopterin concentrations and the kynurenine to tryptophan ratio (Kyn/Trp, an estimate of IDO activity) are elevated in a significant proportion of patients with virus infections, cancer, autoimmune syndrome, neurodegeneration, and coronary artery disease. Moreover, higher neopterin and Kyn/Trp concentrations are indicative for poor prognosis. When investigating the effect of aqueous or ethanolic extracts of cacao on IFN-γ, neopterin and Kyn/Trp concentrations in mitogen-stimulated human peripheral blood mononuclear cells, breakdown of tryptophan by IDO, and formation of neopterin and IFN-γ were dose-dependently suppressed. The effects observed in the cell-based assays are associated with the antioxidant activity of the cacao extracts as determined by the cell-free oxygen radical absorption capacity assay. The influence of cacao extracts on IDO activity could be of particular relevance for some of the beneficial health effects ascribed to cacao: tryptophan breakdown by IDO is strongly involved in immunoregulation, and the diminished availability of tryptophan limits the biosynthesis of neurotransmitter serotonin. The inhibition of tryptophan breakdown by cacao constituents could thus be relevant not only for immune system restoration in patients, but also contribute to mood elevation and thereby improve quality of life. However, the available data thus far are merely in vitro only and future studies need to investigate the influence of cacao on tryptophan metabolism in vivo.

Acute cocoa Flavanols intake has minimal effects on exercise-induced oxidative stress and nitric oxide production in healthy cyclists: a randomized controlled trial

“…However, future research should focus on the effect of chronic CF intake on chronic diseases involving inflammation. Gastrointestinal, nervous, and cardiovascular diseases might benefit from chronic anti-inflammatory properties of CF [ 41 ], as evidenced by a lowered TNF-α and IL-6 in type 2 diabetes patients following 6 weeks of CF supplementation [ 42 ].…”

Analysis of Cocoa Proanthocyanidins Using Reversed Phase High-Performance Liquid Chromatography and Electrochemical Detection: Application to Studies on the Effect of Alkaline Processing

“…1 Flavonoids in cocoa primarily fall into one of three main groups: anthocyanins (4%), flavan-3-ols (37%), and proanthocyanidins (58%). 2 Cocoa flavonoids have been reported to have a number of health beneficial effects including antioxidant, anti-inflammatory, 3,4 cholesterol-lowering, 5 antiatherogenic, 6 and cancer preventive properties. 7−9 Previous work has focused on flavan-3-ols, specifically catechin,1, and (−)-epicatechin, 2, possibly due to their relatively good oral bioavailability and relative ease of analysis (Figure 1).…”

“…Flavonoids in cocoa primarily fall into one of three main groups: anthocyanins (4%), flavan-3-ols (37%), and proanthocyanidins (58%) . Cocoa flavonoids have been reported to have a number of health beneficial effects including antioxidant, anti-inflammatory, , cholesterol-lowering, antiatherogenic, and cancer preventive properties. − …”

Dietary cocoa protects against colitis‐associated cancer by activating the Nrf2/Keap1 pathway

“…In particular, cocoa beans possess major polyphenolic contents, such as anthocyanidins/anthocyanins, catechins, flavonol, glycosides and proanthocyanidins . Cocoa polyphenol has many beneficial effects, such as antioxidant , anti‐inflammatory , hypoglycemic , cardioprotective , and antiproliferative properties . Cocoa induces apoptosis in liver cancer cells by activating caspase 3 .…”