In vivo administration of genistein has no effect on small intestinal epithelial proliferation and apoptosis, but a modest effect on clonogen survival

The soya metabolite genistein possesses anti-proliferative, pro-apoptotic a ctivities in intestinal epithelial cells in vitro and may reduce epithelial cancer incidence. This could involve cell cycle arrest/apoptosis in the pr oliferative or clonogenic cells. We investigated the effects of genistein o n the small intestinal epithelium in vivo. No effect on the number or distr ibution of proliferative cells in the crypts was detected. Similarly, no ch ange in spontaneous apoptotic cell incidence or the characteristic stem cel l apoptotic response following low dose irradiation was observed. Genistein afforded a modest decrease in clonogen radiosensitivity. Hence, using a ra nge of dosing protocols, sub-cutaneous administration of genistein for peri ods of up to 1 week did not alter intestinal epithelial homeostasis. (C) 19 99 Elsevier Science Ireland Ltd. All rights reserved.