title: Estrogen receptor beta is involved in skeletal muscle hypertrophy induced by the phytoecdysteroid ecdysterone.
abstract: METHODS
  The phytoectysteroid ecdysterone (Ecdy) was reported to stimulate protein synthesis and enhance physical performance. The aim of this study was to investigate underlying molecular mechanisms particularly the role of ER beta (ERβ).
  
  
  RESULTS
  In male rats, Ecdy treatment increased muscle fiber size, serum IGF-1 increased, and corticosteron and 17β-estradiol (E2) decreased. In differentiated C2C12 myoblastoma cells, treatment with Ecdy, dihydrotestosterone, IGF-1 but also E2 results in hypertrophy. Hypertrophy induced by E2 and Ecdy could be antagonized with an antiestrogen but not by an antiandrogen. In HEK293 cells transfected with ER alpha (ERα) or ERβ, Ecdy treatment transactivated a reporter gene. To elucidate the role of ERβ in Ecdy-mediated muscle hypertrophy, C2C12 myotubes were treated with ERα (ALPHA) and ERβ (BETA) selective ligands. Ecdy and BETA treatment but not ALPHA induced hypertrophy. The effect of Ecdy, E2, and BETA could be antagonized by an ERβ-selective antagonist (ANTIBETA). In summary, our results indicate that ERβ is involved in the mediation of the anabolic activity of the Ecdy.
  
  
  CONCLUSIONS
  These findings provide new therapeutic perspectives for the treatment of muscle injuries, sarcopenia, and cachectic disease, but also imply that such a substance could be abused for doping purposes.
authors: Center for Preventive Doping Research, German Sport University, Cologne, Germany; Institute of Pharmacy, Freie Universität Berlin, Germany.
authors: Maria Kristina
authors: MK
authors: Parr
authors: Piwen
authors: P
authors: Zhao
authors: Oliver
authors: O
authors: Haupt
authors: Sandrine Tchoukouegno
authors: ST
authors: Ngueu
authors: Jonas
authors: J
authors: Hengevoss
authors: Karl Heinrich
authors: KH
authors: Fritzemeier
authors: Marion
authors: M
authors: Piechotta
authors: Nils
authors: N
authors: Schlörer
authors: Peter
authors: P
authors: Muhn
authors: Wen-Ya
authors: WY
authors: Zheng
authors: Ming-Yong
authors: MY
authors: Xie
authors: Patrick
authors: P
authors: Diel
mesh_terms: D045930:Anabolic Agents / Q000009:adverse effects; D000818:Animals; D002460:Cell Line / Q000187:drug effects; D003907:Dexamethasone / Q000494:pharmacology; D004441:Ecdysterone / Q000009:adverse effects* / Q000737:chemistry / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D047629:Estrogen Receptor beta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells / Q000187:drug effects; D006801:Humans; D006984:Hypertrophy / Q000139:chemically induced / Q000473:pathology; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D017208:Rats, Wistar
chemical_list: D045930:Anabolic Agents; D047629:Estrogen Receptor beta; D004958:Estradiol; D004441:Ecdysterone; D003907:Dexamethasone
keywords: Dietary supplement; Ecdysterone; Estrogen receptor beta; Skeletal muscle; Traditional Chinese medicine