Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
J Med Food. 2012 Sep;15(9):846-50. doi: 10.1089/jmf.2011.0314. Epub 2012 Aug 2.
Flaxseed (FS) is an oilseed rich in phytoestrogens and n-3 polyunsaturated fatty acids, compounds that may attenuate bone loss during aging. We previously demonstrated using the ovariectomized (OVX) rat model of postmenopausal osteoporosis that 10% dietary FS combined with low-dose estrogen therapy (LD) preserves vertebral bone mass and strength more so than either treatment alone. However, it was prudent to also consider the effect of this intervention on uterine tissue as LD, and possibly FS, may have estrogenic, and thus negative, effects on uterine tissue. The present study investigated if FS enhances the estrogenic effect of LD on markers of uterine health in OVX rats. Three-month-old rats were randomized to groups: (1) SHAM, (2) OVX, (3) OVX+FS, (4) OVX+LD, or (5) OVX+FS+LD. Ground FS was added to the AIN-93M diet (100 g/kg of diet), and LD was delivered by subcutaneous implant (0.42 μg of 17β-estradiol/kg of body weight/day) to mimic LD in postmenopausal women. After 12 weeks, histological analyses of uterine tissue demonstrated flattened or cuboidal luminal epithelia organized in a single layer in the OVX group, while FS, LD, and FS+LD induced a single layer of elongated luminal epithelia, columnar in shape. The SHAM group had the greatest epithelial mass. Cell proliferation was similar among all OVX groups. Therefore FS and FS+LD similarly induce estrogen-like effects on the morphology of luminal epithelia that are weaker than in the SHAM group without inducing cell proliferation in OVX rats. Thus, FS does not enhance the estrogenic effect of LD on markers of uterine health in OVX rats.
亚麻籽（FS）是一种富含植物雌激素和 n-3 多不饱和脂肪酸的油籽，这些化合物可能会减轻衰老过程中的骨质流失。我们之前使用去卵巢（OVX）绝经后骨质疏松症大鼠模型证明，10%的饮食 FS 与低剂量雌激素治疗（LD）相结合，比单独使用任何一种治疗方法更能保留椎骨骨量和强度。然而，也有必要考虑这种干预对子宫组织的影响，因为 LD 和可能的 FS 可能对子宫组织具有雌激素作用，从而产生负面影响。本研究调查了 FS 是否增强了 LD 对 OVX 大鼠子宫健康标志物的雌激素作用。3 月龄大鼠随机分为以下几组：（1）SHAM，（2）OVX，（3）OVX+FS，（4）OVX+LD，或（5）OVX+FS+LD。FS 被添加到AIN-93M 饮食中（100 g/kg 饮食），LD 通过皮下植入（0.42 μg 17β-雌二醇/kg 体重/天）来模拟绝经后妇女的 LD。12 周后，子宫组织的组织学分析表明，OVX 组的腔上皮扁平或立方，排列在单层，而 FS、LD 和 FS+LD 诱导单层伸长的腔上皮，呈柱状。SHAM 组的上皮质量最大。所有 OVX 组的细胞增殖相似。因此，FS 和 FS+LD 相似地诱导腔上皮形态类似于雌激素的作用，其作用弱于 SHAM 组，而不会在 OVX 大鼠中诱导细胞增殖。因此，FS 不会增强 LD 对 OVX 大鼠子宫健康标志物的雌激素作用。
