Abstract
Osteoporosis that is associated with ovarian hormone deficiency following menopause (postmenopausal osteoporosis) is by far the most common cause of age-related bone loss. Isoflavone has been reported as a natural substance that possibly minimizes bone loss in postmenopausal women. This study was conducted to investigate the preventing, treating effects of isoflavone on bone loss in ovariectomized rats. 120 Sprague Dawley rats of 13 week-old were devided into 2 groups, a treatment group and prevention group. Each group was consisted of six subgroups; control (CON), sham operated (SH) or ovariectomized (OVX) and isoflavone supplemented goups: OVX+0.25mg isoflavone/kg diet (OL), OVX+0.8mg isoflavone/kg diet(OM) and OVX+2.5mg isoflavone/kg diet(OH). to study the preventing effects of isoflavone on bone loss, OL, OM and OH groups were fed with isoflavone from 4 days after ovariectomization. Treating effects of isoflavone on bone metabolism were investigated with OL, OM, OH groups supplemented with isoflavone from 8 weeks after ovariectomization. Isoflavone supplementation continued for 8 weeks. At 8 weeks after ovariectomization significant increase in alkaline phosphatase occurred comparing with CON and SH group. By isoflavone supplementation from 4 days after ovariectomy alkaline phosphatase and urinary hydroxyproline were lowered and bone mineral density, bone strength of the femur and tibia and bone dry weight were slightly enhanced with no significant difference. Isoflavone supplemented group at the level of 0.8mg/kg diet (OM group) had significantly lower serum alkaline phosphatase, urinary hydroxyproline, and higher strength of femur than OVX group. Groups with isoflavone supplementation fro 8 weeks after ovariectomy had lower level of serum alkaline phosphatase, urinary hydroxyproline than OVX group. Bone mineral density, bone dry weight and bone strength of the femur and tibia were slightly enhanced by isoflavone supplementation. However there was no significanct difference between OVS ad isoflavone supplementation groups. The results suggest that isoflavone might have potential role for preventing postmenopausal bone loss. Isoflavone supplementation at early stage of postemenopause may be beneficial to age-related bone health.
이소플라본 보충이 골다공증의 예방 및 치료에 미치는 영향을 관찰하고자 Sprague-Dawley 암컷을 수술없이 일반식이를 제공한 군(CON), sham-operation 후 일반식이를 제공한 군(SH), 난소절제한 뒤 일반식이를 제공한 군(OVX), 난소절제 후 isoflavone을 공급한 군(OL, OM, OH)으로 나눈 뒤, 난소절제 4일 및 8주 후부터 8주간 이소플라본을 공급하여 혈액의 ALP, sy 중의 hydroxyproline의 변화, 골밀도, 골강도 및 골무게 등을 연구하였다. 골다공증의 예방에 대하여 isoflavone의 효과를 관찰한 결과, ALP는 난소를 절제한 OVX군에서는 CONrns과 SH군에 비해 유의적으로 높은 값을 보였다. 그러나, 난소절제 후 4일부터 8주간 isoflavone을 보충시킨 결과 ALP 활성과 urinary hydroxyproline 함량은 SH군과 비슷하게 낮아졌다. 특히 OM(0.8mg/kg diet)군의 경우 ALP활성과 urnary hydroxyproline 함량이 가장 낮아서 OVX군과 유의적인 차이를 보였다.(p<0.05). 난소적출 후 8주 후에 골밀도를 측정한 결과 난소절제군의 골밀도가 CONrns과 SH군에 비해 유의적으로 낮은 것으로 나타났다. Isoflavone을 보충한 결과 골밀도가 증가하였으나 유의적인 차이는 없어다. 골다공증의 치료효과에 대한 연구결과 alkaline phosphatase activity의 감소, 골밀도, 골강도 및 골무게가 증가하였으나 유의적인 차이는 나타나지 않았다. 이상의 결과는 난소절제 후에 일어나는 골격 대사의 이상은 isoflavone을 보충시킴으로써 어느 정도 정상화시킬 수 있음을 시사한다. 따라서 적절한 양의 isoflavone 보충은 폐경 후 여성의 골대사에 유익한 효과를 줄 것으로 풀이된다.