Experimental approach: Female Sprague-Dawley rats (8 weeks) were fed with cuprizone diet for 5 weeks followed by intraperitoneal injections of alpha-tocopherol (100 mg/Kg) or PBS for 2 weeks (groups E1 and E2, n = 8). Group C (n = 8) was fed with normal pellets followed by intraperitoneal doses of PBS. Open-field test and beam walking were carried out on every 10th day. The mean area of demyelination in the corpus callosum was quantified in Luxol® fast blue (LFB) stained histological sections of the forebrain. Qualitative grading for relative changes in the stains of myelinated fibers was also done.
Findings/Results: During withdrawal of CPZ, AT treatment increased the average speed by 22% in group E1, compared to group E2 (P < 0.05). The mean time to walk the beam was reduced in group E1 by 2.6% compared to group E2 (P < 0.05). The rearing frequency was increased in group E1 during week 6-7 compared to that in the period of CPZ treatment. The mean area of demyelination in the corpus callosum showed a 12% reduction in group E1 compared to group E2 (P < 0.05).
Conclusion and implications: Short-term AT therapy showed improvement in motor dysfunction and reduction of demyelination in the animal model of MS.
METHOD: In total, 24 female Sprague-Dawley rats were divided into three groups. The first group was sham-operated, and the other two groups were ovariectomized. After two months, the right femora of the rats were fractured under anesthesia and internally repaired with K-wires. The sham-operated and ovariectomized control rat groups were administered olive oil (a vehicle), whereas 60 mg/kg of alpha-tocopherol was administered via oral gavage to the alpha-tocopherol group for six days per week over the course of 8 weeks. The rats were sacrificed, and the femora were dissected out. Computed tomography scans and X-rays were performed to assess fracture healing and callus staging, followed by the assessment of callus strengths through the biomechanical testing of the bones.
RESULTS: Significantly higher callus volume and callus staging were observed in the ovariectomized control group compared with the sham-operated and alpha-tocopherol groups. The ovariectomized control group also had significantly lower fracture healing scores than the sham-operated group. There were no differences between the alpha-tocopherol and sham-operated groups with respect to the above parameters. The healed femora of the ovariectomized control group demonstrated significantly lower load and strain parameters than the healed femora of the sham-operated group. Alpha-tocopherol supplementation was not able to restore these biomechanical properties.
CONCLUSION: Alpha-tocopherol supplementation appeared to promote bone fracture healing in osteoporotic rats but failed to restore the strength of the fractured bone.
METHODS: A total of 71 eligible subjects aged 50 to 55 years from Gombak and Kuala Lumpur, Malaysia, were divided into three groups and supplemented with placebo (n=23), α-tocopherol (n=24) or tocotrienol-rich fraction (n=24). Blood samples were collected at baseline and at 3 and 6 months of supplementation for microarray analysis.
RESULTS: The number of genes altered by α-tocopherol was higher after 6 months (1,410) than after 3 months (273) of supplementation. α-Tocopherol altered the expression of more genes in males (952) than in females (731). Similarly, tocotrienol-rich fraction modulated the expression of more genes after 6 months (1,084) than after 3 months (596) and affected more genes in males (899) than in females (781). α-Tocopherol supplementation modulated pathways involving the response to stress and stimuli, the immune response, the response to hypoxia and bacteria, the metabolism of toxins and xenobiotics, mitosis, and synaptic transmission as well as activated the mitogen-activated protein kinase and complement pathways after 6 months. However, tocotrienol-rich fraction supplementation affected pathways such as the signal transduction, apoptosis, nuclear factor kappa B kinase, cascade extracellular signal-regulated kinase-1 and extracellular signal-regulated kinase-2, immune response, response to drug, cell adhesion, multicellular organismal development and G protein signaling pathways.
CONCLUSION: Supplementation with either α-tocopherol or tocotrienol-rich fraction affected the immune and drug response and the cell adhesion and signal transduction pathways but modulated other pathways differently after 6 months of supplementation, with sex-specific responses.