Picherit C, Chanteranne B, Bennetau-Pelissero C, Davicco M J, Lebecque P, Barlet J P, Coxam V
Groupe Ostéoporose, Laboratoire des Maladies Métaboliques et Micronutriments (U3M), I.N.R.A. Clermont-Ferrand/Theix, 63122 St Genès Champanelle, France.
Br J Nutr. 2001 Mar;85(3):307-16. doi: 10.1079/bjn2000252.
The dose-dependent bone-sparing effects of dietary isoflavones (IF) were investigated in adult (7-month-old) Wistar rats. Forty animals were ovariectomised, allocated into four groups of ten rats each, and immediately treated orally with IF at 0 (OVX), 20 (IF20), 40 (IF40) or 80 (IF80) microg/g body weight per d for 91 d; ten sham-operated (SH) controls received the same diet without added IF. Animals were killed on day 91. Both femoral failure load and total femoral, diaphyseal or metaphyseal bone mineral densities (BMD) were lower in OVX animals than in SH animals. Urinary deoxypyridinoline (DPD) excretion, a marker of bone resorption, and plasma osteocalcin (OC) levels, a marker of osteoblast activity, were higher in OVX animals than in SH animals. Total femoral and diaphyseal BMD and femoral failure load were similar in IF-treated rats and SH rats. Although metaphyseal BMD in IF40 or IF80 rats was similar to that in SH rats, its value was lower in IF20 rats than in controls. The day 91 urinary DPD excretion in IF40 and IF80 rats, but not in IF20 rats, was similar to that in SH rats. Day 91 plasma OC concentrations in IF-treated rats were similar to day 45 values, but were decreased in OVX and SH rats. Thus, daily IF consumption prevented ovariectomy-induced bone loss, both by depressing bone resorption and stimulating osteoblast activity. Moreover, as only the highest IF level induced a weak uterotrophic activity, the optimal IF dose which preserves both cancellous and cortical bone, but exhibits no oestrogen-like effects on the uterus, was 40 microg/g body weight per d.
研究了膳食异黄酮（IF）对成年（7月龄）Wistar大鼠的剂量依赖性保骨作用。40只动物接受卵巢切除术，分为四组，每组10只大鼠，立即分别口服给予IF，剂量为0（OVX）、20（IF20）、40（IF40）或80（IF80）μg/g体重，持续91天；10只假手术（SH）对照大鼠接受相同饮食，但不添加IF。在第91天处死动物。OVX组动物的股骨破坏载荷以及股骨、骨干或干骺端的骨矿物质密度（BMD）均低于SH组动物。作为骨吸收标志物的尿脱氧吡啶啉（DPD）排泄量以及作为成骨细胞活性标志物的血浆骨钙素（OC）水平，OVX组动物高于SH组动物。IF处理组大鼠的股骨总BMD、骨干BMD和股骨破坏载荷与SH组大鼠相似。虽然IF40或IF80组大鼠的干骺端BMD与SH组大鼠相似，但IF20组大鼠的该值低于对照组。IF40和IF80组大鼠在第91天的尿DPD排泄量与SH组大鼠相似，但IF20组大鼠不相似。IF处理组大鼠在第91天的血浆OC浓度与第45天的值相似，但OVX组和SH组大鼠的该浓度降低。因此，每日摄入IF可通过抑制骨吸收和刺激成骨细胞活性来预防卵巢切除诱导的骨质流失。此外，由于只有最高IF水平诱导了微弱的子宫营养活性，既能保留松质骨和皮质骨，又对子宫无雌激素样作用的最佳IF剂量为40μg/g体重/天。
