Effects of soy isoflavones extract on the lipid profile and uterus in ovariectomized rats

Abstract

Aim

Although soy isoflavones (ISO) have been shown to relief postmenopausal symptoms, it remains inconclusive whether ISO can improve lipid-profile without uterotrophic effects under estrogen-deficiency. Thus, we investigated the effects of ISO on lipid-profile and uterus of ovariectomized (Ovx) rats.

Materials and methods

Twenty-five adult rats were Ovx or Sham-operated (Sham) and assigned into five groups: Sham and Ovx groups, administered with vehicle solutions; Ovx-E, treated with 10 µg/kg of 17β-Estradiol; Ovx-ISO, treated with 200 mg/kg of ISO; Ovx-E + ISO, treated with estradiol + ISO combined. After fifty days of treatments, rats were euthanized and uterine horns were processed for histomorphometry or to collagen fibers and glycosaminoglycans evaluations. Blood samples were collected to evaluate levels of triglycerides, total cholesterol (TC) and its fractions (HDL/VLDL). Data were subjected to statistical analysis (p < .05).

Results

Uterus weight was lower in Ovx group than the Sham and Ovx-E groups, whereas it was similar between Ovx and Ovx-ISO groups. Histomorphometry showed atrophic uterus in Ovx and Ovx-ISO groups, whereas uterotrophic effects were noticed in Ovx-E and Ovx-E + ISO groups. Collagen fibers-birefringence was higher in Sham, Ovx, and Ovx-ISO groups than in Ovx-E and Ovx-E + ISO groups. Sulfated glycosaminoglycans content was similar among Sham, Ovx, and Ovx-ISO groups, while it was higher in estrogen-treated groups; total glycosaminoglycans content was similar among groups. TC and HDL was higher in Ovx-ISO group, whereas VLDL and triglycerides levels was higher in Ovx-E + ISO group and similar among other groups.

Conclusion

Soy isoflavones at 200 mg/kg have slight beneficial effects on lipid-profile without uterotrophic effects in Ovx rats.

摘要

目的: 虽然大豆异黄酮(isoflavones, ISO)已被证明可以缓解绝经后的症状, 但仍不确定在雌激素缺乏的情况下, ISO是否可以改善血脂水平, 而无子宫影响效应作用, 因此, 我们研究了ISO对去卵巢（Ovx）大鼠血脂和子宫的影响。

材料和方法：25只成年大鼠进行Ovx或者假手术（Sham）, 分为5组：假手术组和Ovx组, 静脉给液。Ovx-E, 用10 µg/kg的17β-雌二醇处理；Ovx-ISO, 以200mg/kg ISO处理； Ovx-E+ISO, 用雌二醇+ISO混合处理。治疗五十天后, 对大鼠实施安乐死, 并对子宫角进行组织形态测定、胶原纤维和糖胺聚糖评估。收集血液样本以评估甘油三酯, 总胆固醇（TC）及其组分（HDL / VLDL）的水平。对数据进行统计分析（p <.05）。

结果：Ovx组的子宫重量低于Sham和Ovx-E组, 而Ovx和Ovx-ISO组的子宫重量相似。组织形态测定显示Ovx和Ovx-ISO组有萎缩性子宫, 而Ovx-E和Ovx-E + ISO组有明显的子宫营养作用。与 Ovx-E和Ovx-E + ISO组相比, Sham组、Ovx组和Ovx-ISO组的胶原纤维双折射率较高。Sham, Ovx和Ovx-ISO组之间的硫酸化糖胺聚糖含量相似, 而经雌激素治疗的组则更高。各组之间总糖胺聚糖含量相似。Ovx-ISO组的TC和HDL较高, 而Ovx-E + ISO组的VLDL和甘油三酯水平较高, 其他组相似。

结论：200mg/kg的大豆异黄酮对Ovx大鼠的脂质略有益处, 而没有子宫营养作用

Keywords:

• Soy Isoflavones
• lipid profile
• uterus
• estrogen deficiency
• rats

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil.