title: Melatonin Protects Human Adipose-Derived Stem Cells from Oxidative Stress and Cell Death.
abstract: BACKGROUND
  Adipose-derived stem cells (ASCs) have applications in regenerative medicine based on their therapeutic potential to repair and regenerate diseased and damaged tissue. They are commonly subject to oxidative stress during harvest and transplantation, which has detrimental effects on their subsequent viability. By functioning as an antioxidant against free radicals, melatonin may exert cytoprotective effects on ASCs.
  
  
  METHODS
  We cultured human ASCs in the presence of varying dosages of hydrogen peroxide and/or melatonin for a period of 3 hours. Cell viability and apoptosis were determined with propidium iodide and Hoechst 33342 staining under fluorescence microscopy.
  
  
  RESULTS
  Hydrogen peroxide (1-2.5 mM) treatment resulted in an incremental increase in cell death. 2 mM hydrogen peroxide was thereafter selected as the dose for co-treatment with melatonin. Melatonin alone had no adverse effects on ASCs. Co-treatment of ASCs with melatonin in the presence of hydrogen peroxide protected ASCs from cell death in a dose-dependent manner, and afforded maximal protection at 100 µM (n=4, one-way analysis of variance P<0.001). Melatonin co-treated ASCs displayed significantly fewer apoptotic cells, as demonstrated by condensed and fragmented nuclei under fluorescence microscopy.
  
  
  CONCLUSIONS
  Melatonin possesses cytoprotective properties against oxidative stress in human ASCs and might be a useful adjunct in fat grafting and cell-assisted lipotransfer.
authors.affiliation: Bernard O'Brien Institute Department, St. Vincent's Institute of Medical Research, Melbourne, Australia.
authors.forename: Shaun S
authors.initials: SS
authors.lastname: Tan
authors.affiliation: Bernard O'Brien Institute Department, St. Vincent's Institute of Medical Research, Melbourne, Australia.
authors.forename: Xiaolian
authors.initials: X
authors.lastname: Han
authors.affiliation: Bernard O'Brien Institute Department, St. Vincent's Institute of Medical Research, Melbourne, Australia.
authors.forename: Priyadharshini
authors.initials: P
authors.lastname: Sivakumaran
authors.affiliation: Bernard O'Brien Institute Department, St. Vincent's Institute of Medical Research, Melbourne, Australia.
authors.forename: Shiang Y
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Bernard O'Brien Institute Department, St. Vincent's Institute of Medical Research, Melbourne, Australia.
authors.forename: Wayne A
authors.initials: WA
authors.lastname: Morrison
keywords: Cytoprotection; Hydrogen peroxide; Melatonin; Mesenchymal stem cell