Event Abstract Back to Event Direct inhibition of osteoclast formation and activity by the vitamin E isomer gamma-tocotrienol P Kalia1*, R Brooks1, DC Ireland1, C Beeton2 and N Rushton1 1 University of Cambridge, Orthopaedic Research Unit, Department of Surgery, United Kingdom 2 University of Cambridge, Department of Medicine, United Kingdom Introduction. Vitamin E homologues, specifically tocotrienols, have been shown to have favourable effects on bone and possess properties which suggest potential anti-resorptive activity. The hypothesis that tocopherols and/or tocotrienols might act as potential anti-resorptive agents was investigated by testing the effect of vitamin E compounds on osteoclast number, formation and resorption.{BR}Materials and Methods. Human osteoclasts were cultured on collagen, dentine and calcium phosphate substrates with or without vitamin E homologues. Compounds were either added at the start of culture to study effects on osteoclast number and formation, and at the start of osteoclastic resorption to determine effects on activity.{BR}Results and Discussion. With increasing dose of gamma-tocotrienol from 0.01 mM to 1 mM, MTS absorbance increased significantly (Figure 1, 0.01M - 0.14 ± 0.01 , 0.1mM - 0.24 ± 0.02 and 1mM - 0.67 ± 0.06; p=0.007). At 0.01 mM and 1 mM, delta-tocotrienol absorbance decreased significantly (0.05 ± 0.06 and 0, compared to 0.1 mM which had 0.17 ± 0.01; p<0.05). Comparing between the different treatment doses alpha-, delta- or gamma-tocotrienols (1 - 0.1 mM), significant differences were found depending on the dose (p=0.024, p=0.018 and p=0.007, respectively). Absorbance increased when the alpha-tocotrienol concentration was increased from 0.1 mM to 1 mM. Alpha- and gamma-tocotrienol inhibited TRAP+ osteoclast formation without reducing total cell number. A reduction in osteoclast-mediated resorption was observed after treatment with 1 and 0.1 mM delta-tocotrienol (Figure 2, 0.01 mM - 7.87 ± 3.68 %, 0.1 mM - 3.05 ± 1.20 %, 1.0 mM - 0.40 ± 0.80 %) and gamma-tocotrienol (0.01 mM - 2.60 ± 0.85 %, 0.1 mM - 2.37 ± 0.32 %, 1.0 mM - 0 %). Only gamma-tocotrienol inhibited osteoclast activity without consequent toxicity. These results were confirmed using cells from a second donor.{BR}In summary, we have identified the vitamin E isomer gamma-tocotrienol as a non-toxic, anti-resorptive compound. Gamma-tocotrienol may have potential applications in the treatment of bone loss. Keywords: Bones, Bone Research Conference: 2011 joint meeting of the Bone Research Society & the British Orthopaedic Research Society, Cambridge, United Kingdom, 27 Jun - 29 Jun, 2011. Presentation Type: Poster Topic: Abstracts Citation: Kalia P, Brooks R, Ireland D, Beeton C and Rushton N (2011). Direct inhibition of osteoclast formation and activity by the vitamin E isomer gamma-tocotrienol. Front. Endocrinol. Conference Abstract: 2011 joint meeting of the Bone Research Society & the British Orthopaedic Research Society. doi: 10.3389/conf.fendo.2011.02.00031 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Sep 2011; Published Online: 30 Sep 2011. * Correspondence: Dr. P Kalia, University of Cambridge, Orthopaedic Research Unit, Department of Surgery, United Kingdom, pk345@cam.ac.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers P Kalia R Brooks DC Ireland C Beeton N Rushton Google P Kalia R Brooks DC Ireland C Beeton N Rushton Google Scholar P Kalia R Brooks DC Ireland C Beeton N Rushton PubMed P Kalia R Brooks DC Ireland C Beeton N Rushton Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.