Effects of soy germ phytoestrogens and estradiol on body weight in ovariectomized rats

ObjectiveTo explore the effects of phytoestrogens(soy germ products)and estradiol on body weight, serum lipids,and ghrelin levels in ovariectomized rats.MethodsOvariectomized Sprague-Dawley rats were fed a basic diet,a diet supplemented with phytoestrogens(0.4 g/kg diet or 1.6 g/kg diet),and a diet with 17-βestradiol(0.15 g/kg diet),respectively,for 12 weeks.The serum lipids,low-density lipoprotein-cholesterol(LDL-C),high-density lipoprotein-cholesterol,free fatty acid,ghrelin,and adipokins levels were measured.ResultsDuring the experiment,the body weight of control rats and the rats receiving soy germ phytoestrogens increased significantly,whereas the body weight of rats receiving 17-βestradiol maintained in a stable level.The increment of body weight of the rats receiving 1.6 g/kg diet of phytoestrogens(48.67 g)and 17-βestradiol(2.10 g)were significantly lower than those of control rats(95.29 g)and the rats receiving 0.4 g/kg diet of phytoestrogens(89.54 g)(P<0.05).The uteri index in the rats receiving 17-βestradiol was significantly higher than that of control rats(P<0.001).The serum ghrelin level in the rats receiving high dose of soy germ phytoestrogens(3.54±0.82 ng/ml)and 17-βestradiol(2.78±0.27 ng/ml)was significantly lower than that of control group (5.03±1.49 ng/ml,P<0.05).No effect of phytoestrogens and 17-βestradiol on serum lipids,lipoproteins and adipokins levels was found.ConclusionSoy germ phytoestrogens and 17-βestradiol may reduce ghrelin levels and thus decrease body weight increment in ovariectomized rats.