title: Polyphenol extract of Greens+™ nutritional supplement stimulates bone formation in cultures of human osteoblast-like SaOS-2 cells.
abstract: OBJECTIVE
  Oxidative stress has been associated with osteoporosis. Greens+™ is a commercially available nutritional supplement containing antioxidative polyphenols.
  
  
  METHODS
  To study the effects of greens+™ on differentiation and bone formation in human osteoblasts, the cells were cultured in Ham's F-12 medium in the absence or presence of varying concentrations of total free polyphenolic (TFP) in the extracts of greens+™.
  
  
  RESULTS
  Our results showed that the number of osteoblasts increased (p <. 05) compared to vehicle control after 2 and 4 days of treatment but were reduced (p <. 05) after 7 days of treatment with 1.2-2.0 mg greens+™ extract/ml (corresponding to 16.8-27.9 ng TFP expressed as gallic acid equivalent per milliliter). Lower concentrations of greens+™ extract stimulated alkaline phosphatase activity at early time points (days 9 and 11), while higher concentrations at the later time point of day 13 resulted in a significant (p <. 05) inhibition, in a time (p <. 0001) and dose dependent (p <. 0001) manner. Greens+™ extract stimulated (p <. 05) the mineralized bone nodule formation in a dose and time dependent manner.
  
  
  CONCLUSIONS
  The results showed that greens+™ extract influenced the maturation of osteoprogenitors toward progression to a bone-forming stage. Our data suggest that greens+™ may have beneficial effects on bone formation in vitro due to its antioxidant polyphenolic content and we can speculate that it may be a good alternative to drugs for the prevention of osteoporosis.
authors.affiliation: Department of Medicine, University of Toronto, Toronto, ON, Canada. leticia.rao@utoronto.ca
authors.forename: Leticia G
authors.initials: LG
authors.lastname: Rao
authors.forename: Bashyam
authors.initials: B
authors.lastname: Balachandran
authors.forename: A Venketeshwer
authors.initials: AV
authors.lastname: Rao
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects*; D010024:Osteoporosis / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D018384:Oxidative Stress / Q000187:drug effects*; D059808:Polyphenols / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000975:Antioxidants; D059808:Polyphenols; D000469:Alkaline Phosphatase