title: Ajuga turkestanica increases Notch and Wnt signaling in aged skeletal muscle.
abstract: BACKGROUND
  The declining myogenic potential of aged skeletal muscle is multifactorial. Insufficient satellite cell activity is one factor in this process. Notch and Wnt signaling are involved in various biological processes including orchestrating satellite cell activity within skeletal muscle. These pathways become dysfunctional during the aging process and may contribute to the poor skeletal muscle competency. Phytoecdysteroids are natural adaptogenic compounds with demonstrated benefit on skeletal muscle.
  
  
  OBJECTIVE
  To determine the extent to which a phytoecdysteroid enriched extract from Ajuga turkestanica (ATE) affects Notch and Wnt signaling in aged skeletal muscle.
  
  
  METHODS
  Male C57BL/6 mice (20 months) were randomly assigned to Control (CT) or ATE treatment groups. Chow was supplemented with either vehicle (CT) or ATE (50 mg/kg/day) for 28 days. Following supplementation, the triceps brachii muscles were harvested and immunohistochemical analyses performed. Components of Notch or Wnt signaling were co-labelled with Pax7, a quiescent satellite cell marker.
  
  
  RESULTS
  ATE supplementation significantly increased the percent of active Notch/Pax7+ nuclei (p = 0.005), Hes1/Pax7+ nuclei (p = 0.038), active B-catenin/Pax7+ nuclei (p = 0.011), and Lef1/Pax7+ nuclei (p = 0.022), compared to CT. ATE supplementation did not change the resting satellite cell number.
  
  
  CONCLUSIONS
  ATE supplementation in aged mice increases Notch and Wnt signaling in triceps brachii muscle. If Notch and Wnt benefit skeletal muscle, then phytoecdysteroids may provide a protective effect and maintain the integrity of aged skeletal muscle.
authors.affiliation: The Laboratory of Systems Physiology, Department of Kinesiology, UNC Charlotte, Charlotte, NC, USA. sarthur8@uncc.edu.
authors.forename: S T
authors.initials: ST
authors.lastname: Arthur
authors.forename: K A
authors.initials: KA
authors.lastname: Zwetsloot
authors.forename: M M
authors.initials: MM
authors.lastname: Lawrence
authors.forename: D C
authors.initials: DC
authors.lastname: Nieman
authors.forename: M A
authors.initials: MA
authors.lastname: Lila
authors.forename: M H
authors.initials: MH
authors.lastname: Grace
authors.forename: R
authors.initials: R
authors.lastname: Howden
authors.forename: I D
authors.initials: ID
authors.lastname: Cooley
authors.forename: J F
authors.initials: JF
authors.lastname: Tkach
authors.forename: M D
authors.initials: MD
authors.lastname: Keith
authors.forename: J L
authors.initials: JL
authors.lastname: Demick
authors.forename: S E
authors.initials: SE
authors.lastname: Blanton
authors.forename: R S
authors.initials: RS
authors.lastname: Greiner
authors.forename: A M
authors.initials: AM
authors.lastname: Bradley
authors.forename: M E
authors.initials: ME
authors.lastname: Davenport
authors.forename: V
authors.initials: V
authors.lastname: Badmaev
authors.forename: R A
authors.initials: RA
authors.lastname: Shanely
mesh_terms: D000367:Age Factors; D031328:Ajuga / Q000737:chemistry*; D000818:Animals; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D011897:Random Allocation; D051880:Receptors, Notch / Q000378:metabolism*; D032496:Satellite Cells, Skeletal Muscle / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction; D051153:Wnt Proteins / Q000378:metabolism; D060449:Wnt Signaling Pathway / Q000187:drug effects*
chemical_list: D010936:Plant Extracts; D051880:Receptors, Notch; D051153:Wnt Proteins