title: Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.
abstract: OBJECTIVE
  Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.
  
  
  METHODS
  Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers.
  
  
  RESULTS
  OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels.
  
  
  CONCLUSIONS
  Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Science, Beijing, People's Republic of China; Center for Special Medicine and Experimental Research, 306 Hospital of PLA, Beijing, People's Republic of China.
authors.forename: JunLi
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Science, Beijing, People's Republic of China.
authors.forename: YiHu
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Center for Special Medicine and Experimental Research, 306 Hospital of PLA, Beijing, People's Republic of China.
authors.forename: ShuJun
authors.initials: S
authors.lastname: Song
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Science, Beijing, People's Republic of China.
authors.forename: XiJie
authors.initials: X
authors.lastname: Wang
authors.affiliation: Center for Special Medicine and Experimental Research, 306 Hospital of PLA, Beijing, People's Republic of China.
authors.forename: YaYa
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Center for Special Medicine and Experimental Research, 306 Hospital of PLA, Beijing, People's Republic of China.
authors.forename: ShaoYan
authors.initials: S
authors.lastname: Si
authors.affiliation: Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Science, Beijing, People's Republic of China.
authors.forename: YanChuan
authors.initials: Y
authors.lastname: Guo
mesh_terms: D015502:Absorptiometry, Photon; D000284:Administration, Oral; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D019355:Calcium Citrate / Q000494:pharmacology*; D002417:Cattle; D003094:Collagen / Q000494:pharmacology*; D024042:Collagen Type I / Q000097:blood; D004195:Disease Models, Animal; D004338:Drug Combinations; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006801:Humans; D015675:Osteocalcin / Q000097:blood; D010024:Osteoporosis / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D010052:Ovariectomy; D010455:Peptides / Q000097:blood / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D050071:Bone Density Conservation Agents; D024042:Collagen Type I; D004338:Drug Combinations; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D003094:Collagen; D000469:Alkaline Phosphatase; D019355:Calcium Citrate