The Delayed Tumorgenesis of Soy Isoflavones on 7,12-dimethylbenz(a)anthracene(DMBA)-Induced Mammary Tumors in Female Spague-Dawley(SD) Rats with or without Ovariectomization

• Main Authors: Yi Fang Chen, 陳怡坊
• Other Authors: Yi-Wen Chien
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/50253093092531870119

碩士 === 臺北醫學大學 === 保健營養學系 === 93 === The aim of this study was to clarify the effects of soy isoflavones on 7,12-dimethylbenz(a)anthracene(DMBA)-induced mammary tumors in sham and ovariectomized female Spague-Dawley (SD) rats. 80 mg /kg body weight DMBA was administrated orally to 48 rats at the age of 7 weeks. Two weeks after DMBA administration, rats were divided into two groups, which were sham-operation and ovariectomy-operation. Each groups was fed three different diets: C diet: #5001 chow diet (SC or OC), S1 diet: #5001 chow diet plus 1g soy isoflavones/kg diet (SS1 or OS1) and S2 diet: #5001 chow diet plus 2g soy isoflavones/kg diet (SS2 or OS2). The numbers and volume of tumors were recorded once a week by palpating rats from the age of 12 weeks. Finally, the rats were sacrificed after 27 weeks of DMBA administration for analysis. The results showed the tumor incidence of SC and SS2 groups were greater than other groups. At the age of 34 weeks, the plasma estradiol concentration of rat showed dose-dependent effects. The liver microsome were analyzed for total cytochrome P450 and isozyme activities：Both EROD activities and PROD activities of sham groups were higher than those of ovariectomy groups except EMD activities. The EMD activities of all groups showed dose-dependent. The results indicated that supplement of 1g isoflavones in diet could decrease tumorgenesis of sham groups, however, supplement of 2g isoflavones in diet could increase tumorgenesis. Both supplement of 1g or 2g isoflavones in diet could inhibit tumorgenesis of ovariectomy groups.