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High-Dose α-Tocopherol Supplementation Does Not Induce Bone Loss in Normal Rats.

Kasai S, Ito A, Shindo K, Toyoshi T, Bando M - PLoS ONE (2015)

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: Vitamin E Information and Technology Section, Customer Joy Department, Eisai Co. Ltd., Tokyo, Japan.

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.

No MeSH data available.


Related in: MedlinePlus

Micro-CT analysis of trabecular bone in vertebral body.(A) Representative 3-dimensional micro-CT images of trabecular bones in vertebral bodies are shown. (B) Microstructural parameters (BV/TV, trabecular bone volume fraction; Tb.N, trabecular number; Tb.SP, trabecular separation; Conn.D, connectivity density; DA, degree of anisotriphy) of trabecular bones in vertebral bodies are shown. Data are presented as mean ± standard error of the mean. ***P < 0.001 vs. sham rat group.
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pone.0132059.g002: Micro-CT analysis of trabecular bone in vertebral body.(A) Representative 3-dimensional micro-CT images of trabecular bones in vertebral bodies are shown. (B) Microstructural parameters (BV/TV, trabecular bone volume fraction; Tb.N, trabecular number; Tb.SP, trabecular separation; Conn.D, connectivity density; DA, degree of anisotriphy) of trabecular bones in vertebral bodies are shown. Data are presented as mean ± standard error of the mean. ***P < 0.001 vs. sham rat group.

Mentions: For the vertebral cancellous bone, OVX rats showed a 28% decreased BV/TV (P < 0.001), 20% decreased Tb.N (P < 0.001), and 29% increased Tb.Sp (P < 0.001) in comparison with sham rats. For the distal femur diaphysis, OVX rats showed a 28% decreased BV/TV (P < 0.01), 55% decreased Tb.N (P < 0.001), 128% increased Tb.Sp (P < 0.001), 61% decreased Conn.D (P < 0.001), and 6% increased DA (P < 0.01) in comparison with sham rats (Figs 2 and 3). Thus, compared with sham rats, OVX rats were confirmed to have a reduced cancellous bone mass and weakened microstructures.


High-Dose α-Tocopherol Supplementation Does Not Induce Bone Loss in Normal Rats.

Kasai S, Ito A, Shindo K, Toyoshi T, Bando M - PLoS ONE (2015)

Micro-CT analysis of trabecular bone in vertebral body.(A) Representative 3-dimensional micro-CT images of trabecular bones in vertebral bodies are shown. (B) Microstructural parameters (BV/TV, trabecular bone volume fraction; Tb.N, trabecular number; Tb.SP, trabecular separation; Conn.D, connectivity density; DA, degree of anisotriphy) of trabecular bones in vertebral bodies are shown. Data are presented as mean ± standard error of the mean. ***P < 0.001 vs. sham rat group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492956&req=5

pone.0132059.g002: Micro-CT analysis of trabecular bone in vertebral body.(A) Representative 3-dimensional micro-CT images of trabecular bones in vertebral bodies are shown. (B) Microstructural parameters (BV/TV, trabecular bone volume fraction; Tb.N, trabecular number; Tb.SP, trabecular separation; Conn.D, connectivity density; DA, degree of anisotriphy) of trabecular bones in vertebral bodies are shown. Data are presented as mean ± standard error of the mean. ***P < 0.001 vs. sham rat group.
Mentions: For the vertebral cancellous bone, OVX rats showed a 28% decreased BV/TV (P < 0.001), 20% decreased Tb.N (P < 0.001), and 29% increased Tb.Sp (P < 0.001) in comparison with sham rats. For the distal femur diaphysis, OVX rats showed a 28% decreased BV/TV (P < 0.01), 55% decreased Tb.N (P < 0.001), 128% increased Tb.Sp (P < 0.001), 61% decreased Conn.D (P < 0.001), and 6% increased DA (P < 0.01) in comparison with sham rats (Figs 2 and 3). Thus, compared with sham rats, OVX rats were confirmed to have a reduced cancellous bone mass and weakened microstructures.

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: Vitamin E Information and Technology Section, Customer Joy Department, Eisai Co. Ltd., Tokyo, Japan.

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.

No MeSH data available.


Related in: MedlinePlus