Antitumor activity and interleukin-1 induction by tannins

The reletionships between structures, antitumor activities and interleukin-1 (IL-1) induction by fifteen tannins were studies. When tannins (10 mg/kg) were intraperitoneally injected into mice once, 4 days before intraperitoneal inoculation of S-180 cells, tellimagrandin II, rugosin A, hirtellin B, oenothein B and oenothein A, which have only tellimagrandins I or II units in their molecules, had significant antitumor activity. Although casuarictin and its related tannins were ineffective, agrimonin, which is a dimer, had a strong effect, as previously reported. On the other hand, monomeric ellagitannins such as tellimagrandins I and II, rugosin A and casuarictin also increased IL-1β production from human peripheral macrophages in vitro by 2-fold over the non-stimulated basal production and oligomeric ellagitannins with strong antitumor activity more potently stimulated the IL-1β induction. Other tannins having no antitumor activity induced less IL-1β. This study indicates that oligomeric ellagitannins, which consist of tellimagrandin I or II, casuarictin or their related structure units, have antitumor activity and induce IL-1β.