title: Antiosteoporotic activity of echinacoside in ovariectomized rats.
abstract: OBJECTIVE
  Echinacoside (ECH), isolated from Cistanche tubulosa (Schrenk) R. Wight stems, has been reported to enhance bone regeneration in MC3T3-E1 cells in vitro. The objectives of this study were to investigate the antiosteoporotic effect of ECH on bone metabolism in the ovariectomized (OVX) rat model of osteoporosis in vivo.
  
  
  METHODS
  Fifty-six aged 6 months female Sprague-Dawley rats were randomly assigned into sham-operated group (SHAM) and six OVX subgroups (n=8 each). The OVX rats were then subdivided into six groups treated with vehicle (OVX), Xian-ling-gu-bao (XLGB, 0.5 g/kg body weight/day, orally), 17β-estradiol (E2, 50 μg/kg body weight/day, orally) or ECH (30, 90, and 270 mg/kg body weight, daily, orally) for 12 weeks respectively. We evaluated the pharmacological effects of E2, XLGB and ECH against osteoporosis by evaluating the body weight, uterus wet weight, serum and urine biochemical parameters, bone mineral density (BMD), bone biomechanical properties, bone microarchitecture, bone histomorphology and uterus immunohistochemistry.
  
  
  RESULTS
  In OVX rats, the increases of body weight, serum hydroxyproline (HOP) levels, and the decreases of uterus wet weight and BMD were significantly reversed by ECH treatment. Moreover, three dosages of ECH completely corrected the increased urine concentration of calcium (Ca), inorganic phosphorus (P), and HOP observed in OVX rats. Furthermore, Micro-CT analysis results of distal femur showed that all ECH-treated groups notably enhanced bone quality compared to OVX group (p<0.05). Consistent with this finding, total femur BMD and biomechanical strength of tibia were significantly improved (p<0.05) after 12 weeks ECH administration. Histological results also showed the protective activity of ECH through promotion of bone formation and suppression of bone resorption. In addition, the ECH administration also significantly enhanced the expression of ER in the uteri according to immunohistochemical evaluation (p<0.05). Those findings, based on the serum and urine biochemical, BMD, Micro-CT, biomechanical test, histopathological and immunohistochemical parameters, showed that ECH has a notable antiosteoporotic effect, similar to estrogen, especially effective for prevention osteoporosis induced by estrogen deficiency.
  
  
  CONCLUSIONS
  These results suggest that ECH, as a new class of phytoestrogen, has a remarkable antiosteoporotic activity, and may be a promising candidate for treatment of postmenopausal osteoporosis induced by estrogen deficiency in a natural way through herbal resources.
authors: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China.
authors: Fei
authors: F
authors: Li
authors: Xiaolin
authors: X
authors: Yang
authors: Yanan
authors: Y
authors: Yang
authors: Changrun
authors: C
authors: Guo
authors: Chunfeng
authors: C
authors: Zhang
authors: Zhonglin
authors: Z
authors: Yang
authors: Ping
authors: P
authors: Li
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology / Q000627:therapeutic use; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D002118:Calcium / Q000652:urine; D031671:Cistanche / Q000737:chemistry*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000172:deficiency; D005260:Female; D006027:Glycosides / Q000494:pharmacology / Q000627:therapeutic use*; D006909:Hydroxyproline / Q000097:blood / Q000652:urine; D009929:Organ Size; D010024:Osteoporosis / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D010052:Ovariectomy; D010758:Phosphorus / Q000652:urine; D048789:Phytoestrogens / Q000494:pharmacology / Q000627:therapeutic use*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D018547:Plant Stems; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014599:Uterus / Q000187:drug effects / Q000378:metabolism
chemical_list: D050071:Bone Density Conservation Agents; D004365:Drugs, Chinese Herbal; D004967:Estrogens; D006027:Glycosides; D048789:Phytoestrogens; D010936:Plant Extracts; C572489:xian ling gu bao; D010758:Phosphorus; D004958:Estradiol; C060297:echinacoside; D006909:Hydroxyproline; D002118:Calcium