大豆异黄酮对7,12-二甲基苯并（α）蒽诱导的大鼠乳腺肿瘤发生率的影响

[Effect of soy isoflavones on the incidence of 7, 12-dimethylbenz (alpha) anthracene-induced breast tumors in rats].

作者信息

Hu Jian-wei, Zhao Xiao-hui, Zhang Yu-mei, Wang Pei-yu

机构信息

Department of Social Medicine and Health Education, Peking University School of Public Health, Beijing 100191, China.

出版信息

Beijing Da Xue Xue Bao Yi Xue Ban. 2010 Jun 18;42(3):288-92.

PMID:20559403

Abstract

OBJECTIVE

To study the effect of soy isoflavones (SI) at various doses on the incidence of breast tumors induced by 7, 12-dimethyl-benz(a) anthracene (DMBA) in ovariectomized and normal rats.

METHODS

96 SD female rats were randomly divided into ovariectomized group and normal group. Rats in the former group were ovariectomized, then those in each group were randomly placed into six subgroups: blank control, positive control, estrogen control, SI of high dose (100 mg/kg SI), moderate dose (50 mg/kg SI) and low dose(10 mg/kg SI) group according to the body weight. All rats received a single oral dose of 5 mg DMBA, except for the blank control and were palpated weekly to monitor the tumor development. Body weight and diet intake were also recorded weekly. Rats were executed 24 weeks after DMBA administration, the incidence of breast tumors in each group was computed and the activities of superoxide dismutase (SOD) and contents of malondialdehyde (MDA) in rats' plasma were examined.

RESULTS

Compared with the positive group, incidence of breast tumors in ovariectomized rats at high, moderate and low dose SI group was not statistically different (P>0.05), and the activities of SOD in those groups were statistically lower(P<0.01); however, incidence of breast tumors in normal rats at high and moderate dose SI group was statistically different from the positive group (P<0.01), and the activities of SOD in those groups were statistically higher(P<0.01).

CONCLUSION

SI of 50 mg/kg and 100 mg/kg could decrease the incidence of breast tumors in normal rats, which may be related to the higher activities of SOD induced by SI; however, SI could not decrease the incidence of breast tumors and inhibit the activities of SOD in ovariectomized rats. The effects of SI on the incidence of breast tumors and antioxidant activities may be influenced by different basal levels of estrogen in ovariectomized and normal rats.

摘要

目的

研究不同剂量大豆异黄酮（SI）对7,12-二甲基苯并(a)蒽（DMBA）诱导的去卵巢大鼠和正常大鼠乳腺肿瘤发生率的影响。

方法

将96只SD雌性大鼠随机分为去卵巢组和正常组。前一组大鼠进行去卵巢手术，然后根据体重将每组大鼠随机分为六个亚组：空白对照组、阳性对照组、雌激素对照组、高剂量SI组（100 mg/kg SI）、中剂量SI组（50 mg/kg SI）和低剂量SI组（10 mg/kg SI）。除空白对照组外，所有大鼠均单次口服5 mg DMBA，每周触诊以监测肿瘤发展。每周还记录体重和饮食摄入量。DMBA给药24周后处死大鼠，计算每组乳腺肿瘤的发生率，并检测大鼠血浆中超氧化物歧化酶（SOD）的活性和丙二醛（MDA）的含量。