Immunostimulation by plant polyphenols: a relationship between tumor necrosis factor-alpha production and tannin structure.

The ability of the naturally occurring tumoricidal ellagitannin coriariin A to stimulate secretion of both IL-1beta and TNF-alpha from human peripheral blood mononuclear cells has been demonstrated. Companion studies with the monomeric gallotannin beta-D-pentagalloylglucose and a synthesized dimeric gallotannin-ellagitannin hybrid suggest that TNF-alpha rather than IL-1beta is the causative agent in tannin-mediated antitumor action in vivo, in contrast to an ealier proposal.