title: Antifibrotic effects of tocotrienols on human Tenon's fibroblasts.
abstract: OBJECTIVE
  To compare the antifibrotic effect of vitamin E isoforms alpha-, gamma-, and delta-tocotrienol on human Tenon's fibroblasts (hTf) to the antimetabolite mitomycin C.
  
  
  METHODS
  Antifibrotic effects of alpha- (40, 60, 80, 100, and 120 microM), gamma- (10, 20, 30, and 40 microM) and delta-tocotrienol (10, 20, 30, and 40 microM) on hTf cultures were evaluated by performing proliferation, migration and collagen synthesis assays. Whereas for vitamin E the exposure time was set to 7 days to mimic subconjunctival application, cultures were exposed only 5 min to mitomycin C 100 microg/ml to mimic intraoperative administration. Cell morphology (phase contrast microscopy) as an assessment for cytotoxicity and cell density by measuring DNA content in a fluorometric assay to determine proliferation inhibition was performed on day 0, 4, and 7. Migration ability and collagen synthesis of fibroblasts were measured.
  
  
  RESULTS
  All tested tocotrienol isoforms were able to significantly inhibit hTf proliferation in a dose-dependent manner (maximal inhibitory effect without relevant morphological changes at day 4 for alpha-tocotrienol 80 microM with 36.7% and at day 7 for alpha-tocotrienol 80 microM with 42.6% compared to control). Degenerative cell changes were observed in cultures with concentrations above 80 microM for alpha- and above 30 microM for gamma- and delta-tocotrienol. The highest collagen synthesis inhibition has been found with 80 microM alpha-tocotrienol (62.4%) and no significant inhibition for mitomycin C (2.5%). Migration ability was significantly reduced in cultures exposed to 80 microM alpha- and 30 microM gamma-tocotrienol (inhibition of 82.2% and 79.5%, respectively, compared to control) and also after mitomycin C treatment (60.0%). Complete growth inhibition without significant degenerative cell changes could only be achieved with mitomycin C.
  
  
  CONCLUSIONS
  In vitro, all tested tocotrienol isoforms were able to inhibit proliferation, migration and collagen synthesis of human Tenon's fibroblasts and therefore may have the potential as an anti-scarring agent in filtrating glaucoma surgery.
authors.affiliation: Department of Ophthalmology, Inselspital, University of Bern, 3010 Bern, Switzerland. christoph.tappeiner@insel.ch
authors.forename: Christoph
authors.initials: C
authors.lastname: Tappeiner
authors.forename: Alexander
authors.initials: A
authors.lastname: Meyenberg
authors.forename: David
authors.initials: D
authors.lastname: Goldblum
authors.forename: Daniel
authors.initials: D
authors.lastname: Mojon
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Zingg
authors.forename: Kalanithi
authors.initials: K
authors.lastname: Nesaretnam
authors.forename: Monika
authors.initials: M
authors.lastname: Kilchenmann
authors.forename: Beatrice E
authors.initials: BE
authors.lastname: Frueh
mesh_terms: D002452:Cell Count; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D005205:Fascia / Q000166:cytology*; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D005355:Fibrosis / Q000188:drug therapy; D006801:Humans; D008858:Microscopy, Phase-Contrast; D016685:Mitomycin / Q000494:pharmacology; D024508:Tocotrienols / Q000494:pharmacology*; D014815:Vitamins / Q000494:pharmacology*
chemical_list: D024508:Tocotrienols; D014815:Vitamins; D016685:Mitomycin; D003094:Collagen
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