Effect of cocoa polyphenolic extract on macrophage polarization

Polyphenols-rich cocoa has many beneficial effects on human health, such as anti-inflammatory effects. Macrophages function as control switches of the immune system, maintaining the balance between pro- and anti-inflammatory activities. We investigated the hypothesis that cocoa polyphenol extract may affect macrophage pro-inflammatory phenotype M1 by favoring an alternative M2 anti-inflammatory state on macrophages deriving from THP-1 cells. Chemical composition, total phenolic content and antioxidant capacity of cocoa polyphenols extracted from roasted cocoa beans were determined.THP-1 cellswere activated with both LPS and INF-? for M1 or with IL-4 for M2 stimulations. Specific cytokines were quantified. Cellular metabolism, through mitochondrial oxygen consumption, and ATP levels were evaluated. In this work it was shown that cocoa polyphenolic extract attenuated in vitro inflammation showing a significantly decreased macrophage response to M1 activation, demonstrated by a significantly lowered secretion of pro-inflammatory cytokines.Moreover, treatment of M1 macrophages with cocoa polyphenols influences macrophage metabolism by promoting oxidative pathways led to a significant increase of O2 consumption by mitochondrial complexes and a higher production of ATP through oxidative phosphorylation. In conclusion cocoa polyphenolic extract suppresses inflammation in M1 phenotype and influences macrophage metabolism by promoting oxidative pathways and M2 polarization of active macrophages.