Effect of genistein and daidzein on glucose uptake in isolated rat adipocytes; comparison with respective glycones.

摘要

Soybeans and soy-based products are rich sources of biologically active isoflavones. Effects of soy isoflavones (genistin and diadzin) and their respective aglycones (genistein and daidzein) on glucose uptake by adipocytes isolated from male Sprague-Dawley rats fed either a normal or high fat diet were determined. Insulin stimulated glucose uptake in a concn.-dependent manner. However, genistin and daidzin and their aglycones inhibited glucose uptake in a concn.-dependent manner (25-100muM). Aglycones inhibited glucose uptake markedly after 30, 60, 120 and 180 min, whereas glycones only inhibited glucose uptake markedly after 120 and 180 min in isolated rat adipocytes. Genistin and daidzin had no significant effect on insulin-stimulated glucose uptake; however, genistein and daidzein significantly inhibited glucose uptake compared to the control by 47.5 and 24.8%, respectively (P < 0.05). Isoflavones also inhibited glucose uptake in adipocytes isolated from rats fed a high fat diet (50% of total calorie intake) compared to controls. Isoflavones enhanced lipolysis in adipocytes isolated from rats fed a high fat diet; the amount of glycerol released by aglycones was greater than that released by glycones. Results show that the inhibitory effect of daidzein on glucose uptake was similar to that of genistein. Aglycones were more potent inhibitors of glucose uptake and more potent stimulators of lypolysis than glycones in adipocytes isolated from rats on high fat diets.