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 activities in intestinal epithelial cells in vitro and may reduce epithelial cancer incidence. This could involve cell cycle arrest/apoptosis in the proliferative or clonogenic cells. We investigated the effects of genistein on the small intestinal epithelium in vivo. No effect on the number or distribution of proliferative cells in the crypts was detected. Similarly, no change in spontaneous apoptotic cell incidence or the characteristic stem cell apoptotic response following low dose irradiation was observed. Genistein afforded a modest decrease in clonogen radiosensitivity. Hence, using a range of dosing protocols, sub-cutaneous administration of genistein for periods of up to 1 week did not alter intestinal epithelial homeostasis.