title: Effects of annatto-derived tocotrienol supplementation on osteoporosis induced by testosterone deficiency in rats.
abstract: BACKGROUND
  Previous animal models have demonstrated that tocotrienol is a potential treatment for postmenopausal osteoporosis. This study evaluated the antiosteoporotic effects of annatto-derived tocotrienol (AnTT) using a testosterone-deficient osteoporotic rat model.
  
  
  METHODS
  Forty rats were divided randomly into baseline, sham, orchidectomized, AnTT, and testosterone groups. The baseline group was euthanized without undergoing any surgical treatment or intervention. The remaining groups underwent orchidectomy, with the exception of the sham group. AnTT 60 mg/kg/day was given orally to the AnTT group, while the testosterone group received testosterone enanthate 7 mg/kg per week intramuscularly for 8 weeks. Structural changes in trabecular bone at the proximal tibia were examined using microcomputed tomography. Structural and dynamic changes at the distal femur were examined using histomorphometric methods. Serum osteocalcin and C-terminal of type 1 collagen crosslinks were measured. Bone-related gene expression in the distal femur was examined.
  
  
  RESULTS
  There were significant degenerative changes in structural indices in the orchidectomized group (P<0.05), but no significant changes in dynamic indices, bone remodeling markers, or gene expression (P>0.05) when compared with the sham group. The AnTT group showed significant improvement in structural indices at the femur (P<0.05) and significantly increased expression of bone formation genes (P<0.05). Testosterone was more effective than AnTT in preventing degeneration of bone structural indices in the femur and tibia (P<0.05).
  
  
  CONCLUSIONS
  AnTT supplementation improves bone health in testosterone-deficient rats by enhancing bone formation. Its potential should be evaluated further by varying the dosage and treatment duration.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
authors.forename: Kok-Yong
authors.initials: KY
authors.lastname: Chin
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
authors.forename: Soelaiman
authors.initials: S
authors.lastname: Ima-Nirwana
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D031212:Bixaceae; D015519:Bone Density / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects*; D002338:Carotenoids / Q000494:pharmacology*; D024042:Collagen Type I / Q000097:blood; D019587:Dietary Supplements; D005269:Femur / Q000000981:diagnostic imaging; D008297:Male; D009919:Orchiectomy; D015675:Osteocalcin / Q000097:blood; D010024:Osteoporosis / Q000188:drug therapy*; D010455:Peptides / Q000097:blood; D010936:Plant Extracts / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000031:analogs & derivatives / Q000494:pharmacology; D013977:Tibia / Q000000981:diagnostic imaging; D024508:Tocotrienols / Q000494:pharmacology*; D055114:X-Ray Microtomography
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010455:Peptides; D010936:Plant Extracts; D024508:Tocotrienols; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D002338:Carotenoids; D013739:Testosterone; C054041:annatto; C004648:testosterone enanthate
keywords: bone remodeling; osteoporosis; testosterone; tocotrienol