染料木黄酮对去势大鼠骨骼矿化及骨质疏松的影响

背景染料木黄酮是植物性雌激素大豆异黄酮的主要成分,其结构与雌激素相似,提示它可能预防或延缓骨质疏松的发生发展.有关染料木黄酮对去势大鼠骨骼矿化及骨钙、磷、锌和锰影响的研究较少.目的研究染料木黄酮对去势大鼠骨骼矿化及骨钙、磷、锌和锰的影响,为染料木黄酮用于预防骨质疏松提供理论依据.设计以实验动物为研究对象的对照性实验研究.单位解放军总医院营养科.材料实验于2003-02/06在解放军军事医学科学院卫生学环境医学研究所完成.10周龄雌性Wistar大鼠(合格证号军医动D98014号),体重(170±20)g.干预实验动物饲正常饲料6周后,改饲AIN-93合成饲料,5 d后按体质量随机分为去势组(n=40)和假手术组(n=7).去势组手术切除双侧卵巢,假手术组只做腹部切开术,恢复5 d后,将去势组按体质量随机分为5组,每组8只去势对照组、雌激素组己烯雌酚20 μg/(kg穌)]、染料木黄酮Ⅰ、Ⅱ、Ⅲ组剂量分别为25,50,100 mg/(kg·d)].饲养3个月,随机抽取各组大鼠6只测量骨密度和骨组织形态计量学相关指标.主要观察指标各组大鼠骨密度、骨矿化相关参数、骨中钙、磷、锌和镁含量.结果大鼠去势后,股骨骨密度(0.247±0.007)g/cm2]降低,平均类骨质宽度(7.04±0.32)μm]增大,骨矿化延迟时间(4 96±0.99)d]和类骨质成熟时间(26.99±7.70)d]延长,骨中钙(251.11±5.31)mg/g]、磷(115.08±3.78)mg/g]、锌(299.69±37.1)μg/g]和镁(4.32±0.12)μg/g],与假手术组比较,差异均有显著性(P＜0.05);补充染料木黄酮后,股骨骨密度(0.250±0.007)g/cm2]有改善的趋势,平均类骨质宽度(4.87±0.77)μm]变窄,骨矿化延迟时间(3.18±0.69)d]和类骨质成熟时间(14.53±3.84)d]缩短,骨中钙(270.00±5.65)mg/g]、磷(124.25±2.37)mg/g]、镁(4.61±0.08)μg/g]含量升高,锌无显著变化.结论染料木黄酮促进去势大鼠类骨质矿化,减少骨中钙、磷、镁丢失,预防骨质疏松的发生.

Effects of genistein on bone mineralization and osteoporosis in ovariectomized rats

BACKGROUND: Genistein is the main component of phytoestrogen soy isoflavone and its structure is similar to estrogen,which suggests that it might prevent or delay osteoporosis. Research on the effects of genistein on bone mineralization and calcium(Ca), phosphor(P), zinc(Zn) and magnesium (Mg) in ovariectomized rats are rare.OBJECTIVE: To investigate the effects of genistein on bone mineralization and Ca,P,Zn and Mg in ovariectomized rats to provide a theoretical gist for the prevention of osteoporosis by genistein.DESIGN: A controlled experiment based on experimental animals.SETTING: Department of Nutrition,General Hospital of Chinese PLA.MATERIALS: The study was conducted in the Institute of Hygiene and Environmental Medicine,Academy of Military Medical Sciences of PLA between February and June 2003. Ten-week old female Wistar rats certification number: (military medical animal): D98014] with a body mass of(170±20) g were selected.INTERVENTIONS: Experimental animals were fed with normal feeding for 6 weeks and then the feeding was changed to AIN-93 compound. Animals were then randomly divided into ovariectomized group (n=40) and sham-operation group(n=7) based on bodyweight after 5 days. Ovariectomized group received ovariectomy and sham-operation group only received abdominal incision. After 5 days of recovery,the ovariectomized group was further randomly divided into 5 subgroups with 8 rats each including ovariectomized control subgroup,estrogen subgroup diethylstilbestrol 20 μg/(kg · d)],genistein Ⅰ,Ⅱ,or Ⅲ subgroupdose of 25,50 or 100 mg/(kg · d)]. After 3months of feeding,6 rats were randomly selected from each group for the detection of bone density and corresponding bone hismorphometric indicators.MAIN OUTCOME MEASURES: Bone density,corresponding parameters of bone mineralization,Ca,P,Zn and Mg contents in bone of mice in each group RESULTS: After ovariectomy,femoral bone density decreased (0. 247± 0.007) g/cm2],mean osteoid width increased(7. 04 ±0. 32)μm],bone mineralization delayed (4.96±0.99) days],osteoid maturity prolonged (26.99±7.70) days],and Ca (251.11± 5.31) mg/g],P(115.08± 3.78) mg/g],Zn (299.69±37.1)μg/g] and Mg(4. 32±0. 12) μg/g]were all significantly different from that of sham-operation group(P<0.05).After the application of genistein,femoral bone density had a tendency of improvement (0. 250±0. 007) g/cm2],mean osteoid width narrowed (4. 97±0.77) μm],bone mineralization delayed time (3.18±0.69) days] and osteoid maturity time(14.53 ±3.84) days] shortened, contents of Ca (270.00±5.65) mg/g],P(124.25±2.37) mg/g] andMg(4.61±0. 08) μg/g]elevated while Zn content had no significant changes.CONCLUSION: Genistein promotes osteoid mineralization,reduces the loss of Ca, P and Mg in the bone and prevent the generation of osteoporosis in unsexed rats