Cocoa procyanidins and human cytokine transcription and secretion

We examined whether cocoa, in its isolated procyanidin fractions (monomer t hrough decamer), would modulate cytokine production at the levels of transc ription and protein secretion in both resting and phytohemagglutinin (PHA)- stimulated peripheral blood mononuclear cells (PBMC). In resting cells, int erleukin (IL)-1 beta and IL-4 gene expression from cocoa-treated cells vari ed markedly among the subjects tested. However, at the protein level, the l arger fractions (pentamer through decamer) stimulated a dramatic increase i n IL-1 beta concentration (up to ninefold) with increasing degree of polyme rization. Similarly, these larger fractions augmented IL-4 concentration by as much as 2 pg/ml, whereas the control displayed levels nearly undetectab le. In the presence of PHA, gene expression also seemed to be most affected by the larger procyanidin fractions. The pentameric through decameric frac tions increased IL-1 beta expression by 7-19% compared with PHA control, wh ereas the hexameric through decameric fractions significantly inhibited PHA -induced IL-4 transcription in the range of 71-86%. This observation at the transcription level for IL-1 beta was reflected at the protein level in PH A-stimulated PBMC, Significant reductions in mitogen-induced IL-4 productio n were also seen at the protein level with the hexamer, heptamer and octame r, Individual oligomeric cocoa fractions were unstimulatory for IL-2 in res ting PBMC, However, when induced with PHA, the pentamer, hexamer and heptam er fractions caused a 61-73% inhibition in IL-2 gene expression, This study offers additional data for the consideration of the health benefits of die tary polyphenols from a wide variety of foods, including those benefits ass ociated specifically with cocoa and chocolate consumption.