title: Melatonin dietary supplement as an anti-aging therapy for age-related bone loss.
abstract: BACKGROUND
  Previous studies have shown that melatonin, an anti-oxidant molecule secreted from the pineal gland, is a positive regulator of bone mass. However, the potential effects of melatonin on bone mass have never been investigated in an old population. The aim of this study was to assess the effects of dietary melatonin supplementation on mass accrual and biomechanical properties of old rat femora.
  
  
  METHODS
  Twenty 22-month-old male Wistar rats were divided into two randomly assigned groups. The first group was treated for 10 weeks with melatonin, whereas the second group was untreated (control). Rat femurs were collected, and their phenotypes and biomechanical properties were investigated by micro-computed tomography, histomorphometry, and a three-point-bending test. Statistical analyses were performed by the Student two-tailed unpaired t-test. In all experiments, a value of p<0.05 was considered significant.
  
  
  RESULTS
  Rats treated with melatonin had higher bone volume, bone trabecular number, trabecular thickness, and cortical thickness in comparison to the control group. Histomorphometric analyses confirmed the increase of bone volume in melatonin-treated rats. In agreement with these findings, melatonin-treated rats showed higher bone stiffness, flexural modulus, and ultimate load compared to controls.
  
  
  CONCLUSIONS
  These compelling results are the first evidence indicating that dietary melatonin supplementation is able to exert beneficial effects against age-related bone loss in old rats, improving the microstructure and biomechanical properties of aged bones.
authors.affiliation: 1 Department of Medicine and Oral Surgery, School of Dentistry, Complutense University , Madrid, Spain .
authors.forename: Isabel F
authors.initials: IF
authors.lastname: Tresguerres
authors.forename: Faleh
authors.initials: F
authors.lastname: Tamimi
authors.forename: Hazem
authors.initials: H
authors.lastname: Eimar
authors.forename: Jake E
authors.initials: JE
authors.lastname: Barralet
authors.forename: Santiago
authors.initials: S
authors.lastname: Prieto
authors.forename: Jesús
authors.initials: J
authors.lastname: Torres
authors.forename: José Luis
authors.initials: JL
authors.lastname: Calvo-Guirado
authors.forename: Jesús A F
authors.initials: JA
authors.lastname: Tresguerres
mesh_terms: D000375:Aging; D000818:Animals; D000975:Antioxidants / Q000737:chemistry; D015519:Bone Density; D001842:Bone and Bones / Q000473:pathology*; D019587:Dietary Supplements; D004195:Disease Models, Animal; D008297:Male; D008550:Melatonin / Q000737:chemistry / Q000627:therapeutic use*; D010024:Osteoporosis / Q000188:drug therapy*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013314:Stress, Mechanical; D055114:X-Ray Microtomography
chemical_list: D000975:Antioxidants; D008550:Melatonin