Effects of Soy Isoflavone on Serum Glucose and Lipid in Orchiectomized Rats

Objective To investigate the effects of environmental endocrine disruptors-phytoestrogen soybean isoflavone on serum glucose and lipid in rats with orchiectomy.Methods Fifty-four healthy clean male Wistar rats aged 7 weeks were randomly divided into 6 groups,9 in each group,according to their weight and named as the groups of SHAM,ORCH,L-SI,M-SI,H-SI and EC.The rats were injected intraperitoneally with 1.5% sodium pentobarbital according to 40 mg/kg,and they were either shamoperated or orchiectomized.The rats were fed on high fat diet for 4 weeks.There was 1,3,9 g soybean isoflavone and 0.45 mg estrobene per kilogram high fat diet in L-SI,M-SI,H-SI and EC respectively.At the 2nd and 4th week,serum insulin,fasting blood glucose and lipid (TG,TC,HDL and LDL) were detected.Results The weights of rats with orchiectomy was significantly decreased compared with sham-operated rats,and compared with the EC group,the weights of other groups'rats were significantly higher.The weight was decreased along with the increase of the dose of soy isoflavone.At the end of 4 weeks,SIF significantly decreased serum glucose compared with ORCH,and the insulin level was significantly increased in M-SI and H-SI group.SIF and estrogen could significantly decrease TC,but they did not have obvious effect on LDL.SIF could not improve HDL level in rats with orchiectomy.Even though there was no statistic difference,the TG levels of SIF groups were deceased.Conclusion SIF can decrease serum glucose level via raising insulin level in rats with orchiectomy.SIF can decrease serum TC level significantly and regulate TG level while there is no influence on HDL and LDL.