Evaluation of the preventive effect of isoflavone extract on bone loss in ovariectomized rats

• Published in: Bioscience, biotechnology, and biochemistry Vol. 68; no. 5; pp. 1040 - 1045
• Main Authors: Lee, Y.B. (Dr. Chung's Food Co. Ltd., Chungjoo (Korea R.)), Lee, H.J, Kim, K.S, Lee, J.Y, Nam, S.Y, Cheon, S.H, Sohn, H.S
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01.05.2004; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Acid Phosphatase - blood; Alkaline Phosphatase - blood; Animals; Biological and medical sciences; bone; Bone Density; BONE DISEASES; Calcium - analysis; Eating; Estradiol - pharmacology; estrogen; EVALUATION; EXTRACTS; Female; FLAVONOIDS; Fundamental and applied biological sciences. Psychology; Genistein - analysis; Glycine max - chemistry; Humans; Isoenzymes - blood; isoflavone; Isoflavones - analysis; Isoflavones - chemistry; Isoflavones - therapeutic use; Organ Size; Osteoporosis - drug therapy; Osteoporosis - prevention & control; Osteoporosis, Postmenopausal - drug therapy; Osteoporosis, Postmenopausal - prevention & control; OVARIECTOMY; PHYTOOESTROGENS; Plant Extracts - chemistry; RATS; Rats, Sprague-Dawley; SOYBEANS; Tartrate-Resistant Acid Phosphatase; UTERUS; Isoflavone; Vertebrata; Mammalia; uterus; Rat; Rodentia; Estrogen; Extract; Bone; ovariectomy
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.68.1040

To examine a potential role for soybean phytoestrogens in postmenopausal bone loss, twenty-four 12-week-old Sprague-Dawley rats were divided randomly into 4 groups and given controlled diets for 16 weeks. The treatment groups were as followed: sham operated, ovariectomized (OVX) control, OVX + isoflavone extract (6.25 g/kg), and OVX + 17β-estradiol (4 mg/kg). OVX treatments reduced femoral and fourth lumbar vertebral bone density and mineral content (p<0.01), decreased uterine weight (p<0.01), accelerated body weight increases (p<0.05), and increased the activities (p<0.01) of both serum alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP). Supplementation with isoflavone prevented the losses of bone density and mineral content caused by OVX (p<0.01). Although both isoflavone and 17β-estradiol exhibited similar bone-sparing ability on the OVX-induced bone loss, the effect of isoflavone was not the same as that of 17β-estradiol on the serum ALP and TRAP, body weight increase, and uterine weight change. We concluded that dietary supplementation with soybean isoflavone can prevent postmenopausal bone loss via a different mechanism of estrogen in OVX rats.