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-I beta and TNF-alpha from human peripher al blood mononuclear cems 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-I be ta is the causative agent in tannin-mediated antitumor action in vivo, in c ontrast to an earlier proposal. (C) 1999 Elsevier Science Ltd. All rights r eserved.