Effect of alpha-tocopherol on bone formation during distraction osteogenesis: a rabbit model (original) (raw)
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Histological Assessment of the Effect of α-Tocopherol on Fracture Healing in Rabbits
Journal of International Medical Research, 2003
To investigate the effect of a-tocopherol (vitamin E) on fracture healing in rabbits, two groups of 10 rabbits were either injected with a-tocopherol (treated) or untreated (controls). The right femurs of both groups were fractured, and the treated group were injected intramuscularly with 20 mg/kg a-tocopherol daily for 5 days starting on the day of fracture. After 21 days, histological sections of the fractured region were examined and scored. Fracture healing had progressed further in the a-tocopherol group than in the control group. A statistically significant difference between the histological grading of fracture healing in the two groups was found. This difference may result from an antioxidant (a-tocopherol) effect on free oxygen radicals in the fracture area. We conclude that a-tocopherol may affect fracture healing favourably and might be useful as a therapeutic agent in clinical fracture management.
Evidence-Based Complementary and Alternative Medicine, 2012
This study investigated the effects of α-tocopherol and palm oil tocotrienol supplementations on bone fracture healing in postmenopausal osteoporosis rats. 32 female Sprague-Dawley rats were divided into four groups. The first group was sham operated (SO), while the others were ovariectomised. After 2 months, the right femora were fractured under anesthesia and fixed with K-wire. The SO and ovariectomised-control rats (OVXC) were given olive oil (vehicle), while both the alpha-tocopherol (ATF) and tocotrienol-enriched fraction (TEF) groups were given alpha-tocopherol and tocotrienol-enriched fraction, respectively, at the dose of 60 mg/kg via oral gavages 6 days per week for 8 weeks. The rats were then euthanized and the femora dissected out for bone biomechanical testing to assess their strength. The callous of the TEF group had significantly higher stress parameter than the SO and OVXC groups. Only the SO group showed significantly higher strain parameter compared to the other treatment groups. The load parameter of the OVXC and ATF groups was significantly lower than the SO group. There was no significant difference in the Young's modulus between the groups. In conclusion, tocotrienol is better than α-tocopherol in improving the biomechanical properties of the fracture callous in postmenopausal osteoporosis rat model.
Tocotrienols in Bone Protection: Evidence from Preclinical Studies
eFood
Osteoporosis is a degenerative bone disease affecting millions, mostly the aging population. Osteoblasts and osteoclasts maintain the balance in bone resorption and formation. Changes occurring in the differentiation, proliferation and activity of these two cell types result in lower bone mass and microarchitecture deterioration, leading to compromised bone strength. Chronic inflammation and oxidative stress disrupt the balance between osteoblasts and osteoclasts. Tocotrienols, vitamin E isoforms with an unsaturated hydrophobic tridecyl chain, reduce oxidative stress and inflammation by downregulating reactive oxygen species, nuclear factor-κB activation and pro-inflammatory cytokines and upregulating the expression of antioxidant enzyme in bone cells. Consequently, tocotrienols increase bone mineralization, promote osteoblast differentiation, and suppress osteoclast formation and differentiation. In vivo studies using various animal models of osteoporosis show improved biomarkers of bone formation and bone strength with tocotrienol supplementation. Tocotrienol-mediated downregulation of the mevalonate pathway that provides substrates for the biological activities of small guanosine triphosphate-binding proteins may also contribute to the regulation of osteoblasts and osteoclasts. Clinical studies are needed to confirm the bone-protection offered by tocotrienols that are found in abundance in plant foods such as fruits, vegetables, nuts, seeds and oils, which are also known for their antioxidant and anti-inflammatory effects.
Tocotrienols for bone health: a translational approach
Annals of the New York Academy of Sciences, 2017
Osteoporosis, a degenerative bone disease, is characterized by low bone mass and microstructural deterioration of bone tissue resulting in aggravated bone fragility and susceptibility to fractures. The trend of extended life expectancy is accompanied by a rise in the prevalence of osteoporosis and concomitant complications in the elderly population. Epidemiological evidence has shown an association between vitamin E consumption and the prevention of age-related bone loss in elderly women and men. Animal studies show that ingestion of vitamin E, especially tocotrienols, may benefit bone health in terms of maintaining higher bone mineral density and improving bone microstructure and quality. The beneficial effects of tocotrienols on bone health appear to be mediated via antioxidant/anti-inflammatory pathways and/or 3-hydroxy-3-methylglutaryl coenzyme A mechanisms. We discuss (1) an overview of the prevalence and etiology of osteoporosis, (2) types of vitamin E (tocopherols versus tocotrienols), (3) findings of tocotrienols and bone health from published in vitro and animal studies, (4) possible mechanisms involved in bone protection, and (5) challenges and future direction for research.
Current drug targets, 2018
There are accumulating studies reporting vitamin E in general exhibits bone protective effects. This systematic review, however discusses the effects of a group of vitamin E isomers, tocotrienols in preventing bone loss through osteoclast differentiation and activity suppression. This review is aimed to discuss the literature reporting the effects of tocotrienols on osteoclasts, the cells specialized for resorbing bone. Literature search for relevant studies was conducted using SCOPUS and PUBMED MEDLINE. The inclusion criteria were original research articles published that reported the effect of any tocotrienol isomers or treatment with mixture containing tocotrienols on osteoclasts. Out of the total 22 studies from the literature search, only 11 of them were identified as relevant, which comprised of eight animal studies, two in vitro studies and only one combination of both. The in vivo studies indicated that tocotrienols improve the bone health and reduce bone loss via inhibition...
Nutrients, 2021
Recent cohort studies indicate a potential role of the antioxidant α-tocopherol in reducing bone loss and risk of fractures, especially hip fractures. We performed a Mendelian randomization investigation of the associations of circulating α-tocopherol with estimated bone mineral density (eBMD) using heel ultrasound and fractures, identified from hospital records or by self-reports and excluding minor fractures. Circulating α-tocopherol was instrumented by three genetic variants associated with α-tocopherol levels at p < 5 × 10−8 in a genome-wide association meta-analysis of 7781 participants of European ancestry. Summary-level data for the genetic associations with eBMD in 426,824 individuals and with fracture (53,184 cases and 373,611 non-cases) were acquired from the UK Biobank. Two of the three genetic variants were strongly associated with eBMD. In inverse-variance weighted analysis, a genetically predicted one-standard-deviation increase of circulating α-tocopherol was assoc...
Intake and serum levels of [alpha]-tocopherol in relation to fractures in elderly women and men
Bone Abstracts, 2013
Background: A reduction in the formation of free radicals and oxidative stress might reduce the rate of bone loss and muscle wasting. Objective: The objective was to determine whether a-tocopherol intake or serum concentrations are associated with fracture risk in older women and men. Design: Two cohort studies, the Swedish Mammography Cohort (SMC; n = 61,433 women) and the Uppsala Longitudinal Study of Adult Men (ULSAM; n = 1138 men), were used. Results: During 19 y of follow-up, 14,738 women in the SMC experienced a first fracture at any site (3871 hip fractures). A higher hip fracture rate was observed with lower intakes of a-tocopherol. Compared with the highest quintile of intake, the lowest quintile had a multivariable-adjusted HR of 1.86 (95% CI: 1.67, 2.06). The HR of any fracture was 1.20 (95% CI: 1.14, 1.28). a-Tocopherolcontaining supplement use was associated with a reduced rate of hip fracture (HR: 0.78; 95% CI: 0.65, 0.93) and any fracture (HR: 0.86; 95% CI: 0.78, 0.94). Compared with the highest quintile of a-tocopherol intake in ULSAM (follow-up: 12 y), lower intakes (quintiles 1-4) were associated with a higher rate of hip fracture (