Effects of ginkgo biloba on in vitro osteoblast cells and ovariectomized rat osteoclast cells.
Ginkgo biloba extract (GBE) has a selective estrogen receptor modulator (SERM)-like biphasic effect on estrogen, and could be a potential alternative to hormone replacement therapy (HRT). Here, we investigated whether GBE can ameliorate estrogen-depleted osteoporosis in in vitro osteoblast cells and in estrogen-deprived ovariectomized (OVX) rats, a classical animal model for postmenopausal osteoporosis. GBE (50-150 microg/mL) significantly increased ALP (Alkaline phosphatase) activity of osteoblast cells, indicating that GBE promotes osteoblast mineralization. OVX rats exposed to GBE (100 and 200 mg/kg/day, oral treatment), raloxifene (3 mg/kg/day, oral treatment) or estradiol (E2, 10 microg/kg/day, subcutaneous injection) decreased osteoclast resorptive activity compared with OVX rats. GBE and raloxifene did not increase uterine weight compared with OVX rats, while E2 and Sham control did, suggesting that GBE has no uterotrophic activity, which is a disadvantage of estrogen therapy. In OVX rats, GBE did not restore severe bone density loss induced by OVX, indicating that GBE may be insufficient as therapeutic material for severe osteoporosis. However, despite its no effects on bone density loss in OVX rats, GBE did stimulate osteoblast differentiation and antiosteoclastic activity in vitro. Therefore, GBE may have preventive potential on osteoporosis as do other phytoestrogens.
Oh
Seung Min
SM
College of Pharmacy, Sungkyunkwan University, Suwon 440-746, Korea.
Kim
Ha Ryong
HR
Chung
Kyu Hyuck
KH
D000469:Alkaline Phosphatase / Q000032:analysis / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D001862:Bone Resorption / Q000517:prevention & control; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D005260:Female; D020441:Ginkgo biloba / Q000737:chemistry*; D009929:Organ Size / Q000187:drug effects; D010006:Osteoblasts / Q000187:drug effects*; D010010:Osteoclasts / Q000187:drug effects*; D010024:Osteoporosis / Q000517:prevention & control; D010052:Ovariectomy; D010936:Plant Extracts / Q000494:pharmacology; D051381:Rats; D013778:Tetrazolium Salts / Q000378:metabolism; D014599:Uterus / Q000187:drug effects
C110656:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium; D010936:Plant Extracts; D013778:Tetrazolium Salts; D000469:Alkaline Phosphatase