茶多酚对乳腺增生模型大鼠的治疗作用

Effect of tea polyphenols on hyperplasia of mammary glands in rats

目的研究茶多酚对雌、孕激素诱致大鼠乳腺增生的治疗作用。方法50只SD未孕雌性大鼠随机分为5组,每组10只。正常对照组肌内注射(肌注)生理盐水1mL·kg-1.d-1,其他各组动物肌注苯甲酸雌二醇0.5mg·kg-1.d-1,连续25d,后改为黄体酮4mg·kg-1.d-1,连续5d诱致乳腺增生模型。于d31开始,正常对照组和模型组灌胃给予蒸馏水,乳结平组给予芦笋菠萝蛋白酶3.3g·kg-1.d-1,茶多酚高剂量组给予茶多酚300mg·kg-1.d-1,茶多酚低剂量组给予茶多酚150mg·kg-1.d-1,均连续给药30d。观察各组大鼠乳腺高度和直径、子宫指数、激素水平及相关受体表达。结果与正常对照组比较,模型组大鼠乳腺高度和直径增大,子宫指数、雌二醇和催乳素水平升高,孕酮水平降低(P<0.01),乳腺组织雌激素受体(ER)和孕激素受体(PR)表达增强(P<0.01)。与模型组比较,茶多酚高、低剂量组大鼠乳腺高度和直径均减小,子宫指数、雌二醇和催乳素水平均降低,孕酮水平升高(P<0.05),乳腺组织ER和PR表达降低(P<0.01)。结论茶多酚对雌、孕激素诱致大鼠乳腺增生具有抑制作用,其作用机制可能与其调节体内激素水平、降低乳腺组织ER和PR的表达有关。

AIM To investigate the therapeutic effect of tea polyphenols （TP） on mammary hyperplasia in rats induced by estrogen and progestogen. METHODS Fifty virgin female SD rats were randomized into 5 groups, 10 in each. Rats in the control group were administered with normal saline intramuscularly, the rats in other groups were treated with estradiol benzoate （0.5 mg ·kg^-1·d^-1） intramuscularly for 25 days, and followed with progesterone （4 mg·kg^-1·d^-1） for another 5 days to induce hyperplasia model. From the 31st day, the rats in the control group and model group were received distilled water by gavage, the rats in rujieping group were treated with asparagus and bromelin （3.3 g·kg^-1·d^-1）, and the rats in the TP high dose and low dose group were respectively administered with TP 300 mg·kg^-1·d^-1 and 150 mg·kg^-1·d^-1, all for 30 days. The nipple height and diameter, uterus index, the levels of hormone, and the espression of related receptors were observed. RESULTS Compared with the control group, nipple height and diameter, uterus index, and the level of estradiol arid lactogen in the model group increased significantly （P 〈 0.01 ）, the level of progesterone decreased significantly （P 〈 0.01） , and the expression of estradiol receptor （ER） and progesterone receptor （PR） increased remarkably （P 〈 0.01）. Compared with the model group, nipple height and diameter, uterus index, and the level of estradiol and lactogen in the TP high dose and low dose group decreased, the level of progesterone increased significantly （P 〈 0.05）, and the expression of ER and PR in breast tissue decreased remarkably （P 〈 0.01）. CONCLUSION TP could inhibit the hyperplasia of mammary glands induced by estrogen and progestogen, whose mechanism might be associated with the regulation of hormone levels in the body and reduction of the expression of ER and PR in breast tissue.