Protective effect of egg yolk peptide on bone metabolism.
OBJECTIVE
Osteoporosis is a major health problem worldwide, and most current therapy used in osteoporosis treatment acts by either increasing bone formation or decreasing bone resorption. However, the adverse effects of these therapies may preclude their long-term use. We examined the effects of egg yolk water-soluble peptide (YPEP) on bone metabolism as an alternative to current therapeutic agents in ovariectomized (OVX) rats.


METHODS
In the first step, the in vitro effects of YPEP on bone loss were determined. The proliferation, collagen content, and alkaline phosphatase activity of preosteoblastic MC3T3-E1 cells and osteoclastogenesis from bone marrow-derived precursor cells were measured. The in vivo experiment confirmed the positive effect of YPEP on bone tissue. Three-month-old female Sprague-Dawley rats were either sham operated or ovariectomized and fed commercial chow diet or 0.1% YPEP-supplemented diet for 3 month.


RESULTS
YPEP increased preosteoblastic MC3T3-E1 cell proliferation and alkaline phosphatase activity in a dose-dependent manner. Collagen content was also increased by YPEP treatment. Furthermore, YPEP potently suppressed osteoclastogenesis from bone marrow-derived precursor cells. YPEP (100 μg/mL) abolished the formation of osteoclasts positive for tartrate-resistant acid phosphatase. OVX rats supplemented with YPEP showed an osteoprotective effect, as the bone mineral density and cortical thickness in the tibia were increased compared with the OVX controls. Moreover, histological data indicate that YPEP prevented the cancellous bone loss induced by ovariectomy. None of these protective effects were observed in casein-treated rats.


CONCLUSIONS
The present study suggests that YPEP is a promising alternative to current therapeutic agents for the management of osteoporosis.
Department of Food and Biotechnology, Hanseo University, Seosan, Chungnam, South Korea.
Hye Kyung
HK
Kim
Sena
S
Lee
Kang-Hyun
KH
Leem
D000469:Alkaline Phosphatase / Q000032:analysis / Q000097:blood; D000818:Animals; D015519:Bone Density / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology; D001862:Bone Resorption / Q000188:drug therapy; D001842:Bone and Bones / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003094:Collagen / Q000032:analysis; D015387:Egg Proteins, Dietary / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005269:Femur / Q000033:anatomy & histology; D010006:Osteoblasts / Q000737:chemistry / Q000166:cytology / Q000187:drug effects; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D010024:Osteoporosis / Q000517:prevention & control*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley
D015387:Egg Proteins, Dietary; D003094:Collagen; D000469:Alkaline Phosphatase