Phloridzin improves absorption of genistin in isolated rat small intestine

Background & aims: Cancer-protective effects of isoflavones like genistin or genistein are well known. High intakes and an adequate absorption rate of isoflavones are necessary for efficient chemoprevention, though other dietary agents might increase absorption efficacy. The aim of this study was to investigate the effect of phloridzin, an inhibitor of the sodium-dependent glucose transporter (SGLT1), on genistin absorption and metabolism. Methods: Phloridzin and genistin were luminally administered in an isolated preparation of luminally and vascularly perfused rat small intestine. A synthetic perfusate free from blood components was used as vascular medium, with a perfluorocarbon as oxygen carrier. Luminal media consisted of a bicarbonate buffered sodium chloride solution spiked with genistin (24.5 μmol/l) and phloridzin (1 mmol/l). Results: In previous experiments, genistin absorption rate of 17.2% has been observed. In the present study, phloridzin administered simultaneously with genistin, increased genistin uptake 2.5 fold (44.5%). Conclusion: The naturally occurring substance phloridzin, present in apples, thus considerably amplify genistin absorption. These effects might offer a promising novel method in designing functional foods for cancer prevention by combining genistin- and phloridzin-containing foods.