title: High-Dose α-Tocopherol Supplementation Does Not Induce Bone Loss in Normal Rats.
abstract: Oxidative stress affects bone turnover. Preventative effects of antioxidants such as vitamin E on reduced bone mineral density and fractures associated with aging, osteoporosis, and smoking have been examined in animals and humans. The effects of vitamin E (α-tocopherol; αT) on bone health have yielded conflicting and inconclusive results from animal studies. In this study, to determine the bone effects of αT, we investigated the in vivo effects of αT on the bone mineral density, bone mass, bone microstructure, bone resorption, and osteogenesis through peripheral quantitative computed tomography (pQCT) measurements, micro-computed tomography (micro-CT) analyses, and bone histomorphometry of lumbar vertebrae and femurs in normal female Wistar rats fed diets containing αT in different quantities (0, 30, 120, or 600 mg/kg diet) for 8 weeks. To validate our hypotheses regarding bone changes, we examined ovariectomized rats as an osteoporosis model and control sham-operated rats in parallel. As expected, ovariectomized rats had reduced bone mineral density in lumbar vertebrae and the distal metaphyses of their femurs, reduced bone mass and deteriorated microstructure of cancellous bones in the vertebral body and distal femur metaphyses, and reduced bone mass due to resorption-dominant enhanced bone turnover in secondary cancellous bones in these sites. In comparison, αT administered to normal rats, even at the highest dose, did not induce reduced bone mineral density of lumbar vertebrae and femurs or a reduced bone mass or fragile microstructure of cancellous bones of the vertebral body and distal femur metaphyses. Instead, αT-fed rats showed a tendency for an osteogenesis-dominant bone mass increase in secondary cancellous bones in the vertebral body, in which active bone remodeling occurs. Thus, αT consumption may have beneficial effects on bone health.
authors.affiliation: Vitamin E Information and Technology Section, Customer Joy Department, Eisai Co. Ltd., Tokyo, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Kasai
authors.affiliation: Ito Bone Histomorphometry Institute, Niigata, Japan.
authors.forename: Akemi
authors.initials: A
authors.lastname: Ito
authors.affiliation: Canon Lifecare Solutions Inc., Tokyo, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Shindo
authors.affiliation: Study Department, Nihon Bioresearch Inc., Gifu, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Toyoshi
authors.affiliation: Eisai Product Creation Systems, Eisai Co. Ltd., Tsukuba, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Bando
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000633:toxicity*; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D001851:Bone Diseases, Metabolic / Q000139:chemically induced*; D016723:Bone Remodeling / Q000187:drug effects; D001862:Bone Resorption / Q000139:chemically induced; D019587:Dietary Supplements; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D005269:Femur / Q000737:chemistry / Q000000981:diagnostic imaging / Q000648:ultrastructure; D006801:Humans; D021621:Imaging, Three-Dimensional; D008159:Lumbar Vertebrae / Q000737:chemistry / Q000000981:diagnostic imaging / Q000648:ultrastructure; D010012:Osteogenesis / Q000187:drug effects; D015663:Osteoporosis, Postmenopausal; D010052:Ovariectomy; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar; D055114:X-Ray Microtomography; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D024502:alpha-Tocopherol