Treatment with ascorbic acid and alpha-tocopherol modulates oxidative-stress markers in the spinal cord of rats with neuropathic pain

Vitamin E (vit. E) and vitamin C (vit. C) are antioxidants that inhibit nociception. The effect of these vitamins on oxidative-stress markers in the spinal cord of rats with chronic constriction injury (CCI) of the sciatic nerve is unknown. This study investigated the effect of intraperitoneal administration of vit. E (15 mg·kg-1·day-1) and vit. C (30 mg·kg-1·day-1), given alone or in combination, on spinal cord oxidative-stress markers in CCI rats. Adult male Wistar rats weighing 200-250 g were divided equally into the following groups: Naive (rats did not undergo surgical manipulation); Sham (rats in which all surgical procedures involved in CCI were used except the ligature), and CCI (rats in which four ligatures were tied loosely around the right common sciatic nerve), which received injections of vitamins or vehicle (saline containing 1% Tween 80) for 3 or 10 days (n=6/each group). The vitamins prevented the reduction in total thiol content and the increase in superoxide-anion generation that were found in vehicle-treated CCI rats. While nitric-oxide metabolites increased in vehicle-treated CCI rats 3 days after surgery, these metabolites did not show significant changes in vitamin-treated CCI rats. In all rats, total antioxidant capacity and hydrogen-peroxide levels did not change significantly. Lipid hydroperoxides increased 25% only in vehicle-treated CCI rats. These changes may contribute to vit. C- and vit. E-induced antinociception, because scavenging reactive oxygen species seems to help normalize the spinal cord oxidative status altered by pain.

Grape extract and α-Tocopherol effect in cardiovascular disease model of Apo E -/- Mice / Efeito do extrato de uva e α-Tocoferol em camundongos Apo E -/-, modelo de doença cardiovascular

PURPOSE: To verify the effect of consumption of grape extract isolated or combined with α-tocopherol supplementation on atherosclerosis model with Apo E -/- mice. METHODS: After six weeks of atherogenic diet, Apo E -/- mice were divided into the following groups: Control, Grape, Tocopherol and Grape plus Tocopherol. The treatment progressed for 11 weeks when animals were submitted to euthanasia. RESULTS: All the treatments presented hypocholesterolemic effect with reduction of serum and liver cholesterol levels. This effect was parallel to an increase in the fecal excretion of cholesterol. There was also a higher fecal excretion of saturated fatty acids in groups receiving grape extract or α-tocopherol. All the groups treated presented a tendency to show higher levels of vitamin E. The fatty acid profile showed a tendency for monounsaturated fatty acid preservation after grape extract and α-tocopherol consumption. Morphological analysis revealed a lower degree of evolution of the atherosclerotic plaque of the animals that were fed α-tocopherol combined with grape extract, even when no difference was found in the size of the largest lesion. CONCLUSION: A synergistic effect between the polyphenols and α-tocopherol was observed, resulting in diminished evolution of atherosclerosis and a greater beneficial effect on atherosclerosis than the isolated consumption of antioxidants.

OBJETIVO: Verificar o efeito do consumo de extrato de uva isolada ou combinada com a suplementação de α-tocoferol em modelo de aterosclerose, utilizando camundongos Apo E -/-. MÉTODOS: Os camundongos Apo E -/- foram tratados com dieta aterogênica por seis semanas e foram divididos em quatro grupos: Controle, Uva, Tocoferol e Uva e Tocoferol. Após 11 semanas de tratamento os animais foram submetidos à eutanasia. RESULTADOS: Todos os tratamentos apresentaram efeito hipocolesterolêmico, com redução de colesterol plasmático e hepático. Este efeito foi acompanhado de um aumento na excreção fecal de colesterol. Houve também uma maior excreção fecal de ácidos graxos saturados nos grupos que receberam extrato de uva ou de α-tocoferol. Todos os grupos apresentaram uma tendência a apresentar níveis mais elevados de vitamina E. O perfil de ácidos graxos mostrou uma tendência para a preservação de ácidos graxos monoinsaturados, após consumo de extrato de uva e α-tocoferol. A análise morfológica revelou um menor grau de evolução da placa aterosclerótica dos animais que foram alimentados com α-tocoferol combinado com extrato de uva, mesmo quando não houve diferença no tamanho da lesão. CONCLUSÃO: Foi observado um efeito sinergístico entre os polifenóis e α-tocoferol, resultando na redução na evolução da aterosclerose e um maior de efeito benéfico na aterosclerose do que o consumo isolado de antioxidantes sobre a aterosclerose do que o consumo isolado de antioxidantes.

Inhibitory action of antioxidants (ascorbic acid or α-tocopherol) on seizures and brain damage induced by pilocarpine in rats / Ação inibitória de antioxidantes (ácido ascórbico e α-tocoferol) nas convulsões e dano cerebral em ratos induzidos pela pilocarpina

Temporal lobe epilepsy is the most common form of epilepsy in humans. Oxidative stress is a mechanism of cell death induced by seizures. Antioxidant compounds have neuroprotective effects due to their ability to inhibit free radical production. The objectives of this work were to comparatively study the inhibitory action of antioxidants (ascorbic acid or α-tocopherol) on behavioral changes and brain damage induced by high doses of pilocarpine, aiming to further clarify the mechanism of action of these antioxidant compounds. In order to determinate neuroprotective effects, we studied the effects of ascorbic acid (250 or 500 mg/kg, i.p.) and α-tocopherol (200 or 400 mg/kg, i.p.) on the behavior and brain lesions observed after seizures induced by pilocarpine (400 mg/kg, i.p., P400 model) in rats. Ascorbic acid or α-tocopherol injections prior to pilocarpine suppressed behavioral seizure episodes. These findings suggested that free radicals can be produced during brain damage induced by seizures. In the P400 model, ascorbic acid and α-tocopherol significantly decreased cerebral damage percentage. Antioxidant compounds can exert neuroprotective effects associated with inhibition of free radical production. These results highlighted the promising therapeutic potential of ascorbic acid and α-tocopherol in treatments for neurodegenerative diseases.

A epilepsia de lobo temporal é a mais comum forma de epilepsia em humanos. O estresse oxidativo é um dos mecanismos de morte celular induzida pelas crises convulsivas. Os compostos antioxidantes apresentam efeitos neuroprotetores devido à sua capacidade de inibir a produção de radicais livres. Os objetivos do presente trabalho foram estudar de forma comparativa a ação inibitória de antioxidantes (ácido ascórbico e α-tocoferol) sobre as alterações comportamentais e histopatológicas no hipocampo de ratos após convulsões induzidas pela pilocarpina. A fim de determinar os efeitos neuroprotetores destas drogas, o presente trabalho estudou os efeitos do ácido ascórbico (250 ou 500 mg/kg, i.p.) e do α-tocoferol (200 ou 400 mg/kg, i.p.) sobre o comportamento e as lesões cerebrais observados após convulsões induzidas pela pilocarpina (400 mg/kg, i.p., P400), em ratos. As injeções de ácido ascórbico ou α-tocoferol antes da administração de pilocarpina reduzem o número de animais que convulsionam. Estes achados sugerem que os radicais livres podem induzir o desenvolvimento de lesão cerebral durante as crises epilépticas. No modelo P400, o ácido ascórbico e o α-tocoferol, diminuem significativamente os danos cerebrais. Os compostos antioxidantes podem exercer efeitos neuroprotetores, e esses resultados podem estar associados à inibição da produção de radicais livres. Estes resultados sugerem um promissor potencial terapêutico tanto para o ácido ascórbico quanto para o α-tocoferol no tratamento de doenças neurodegenerativas.

Effects of radiation and alpha-tocopherol on saliva flow rate, amylase activity, total protein and electrolyte levels in oral cavity cancer.

OBJECTIVE: The objective of the present study was to evaluate early and late effects of radiation and a-tocopherol on the secretion rate of saliva and on selected saliva salivary parameters in oral cavity cancer patients. PATIENTS & METHODS: Eighty-nine histologically confirmed oral cavity cancer patients (OCC) were enrolled in the study. Resting whole saliva was collected before, during and at the end of the radiation therapy (RT) and simultaneous supplementation with alpha - tocopherol to the radiation treated patients (RT + AT). RESULTS: Salivary flow rate, pH, amylase activity, total protein, sodium and potassium were analyzed. Increased pH, potassium and decreased flow rate, amylase activity, protein content and sodium were observed in 6 weeks of radiation treated patients when compared to OCC patients. A significant improvement of those parameters was observed on alpha - tocopherol supplementation in RT + AT patients. CONCLUSION: Supplementation with alpha - tocopherol improves the salivary flow rate thereby, maintains salivary parameters.

Antioxidant vitamins improves hemoglobin level in children with group a beta hemolytic streptococcal infection.

A study was done on school children infected with group A beta hemolytic streptococci to examine whether antioxidant vitamins play a role in improving the hemoglobin level. A total of 606 primary school children aged 5 to 15 years were randomly divided into two intervention groups. Group 1 (n=299) was treated with pehnoxymethyl penicillin V and group 2 (n=307) was treated with phenoxymethyl penicillin V plus antioxidant vitamins for eight weeks. From each group two blood samples were drawn in acute and convalescent (after eight weeks) states. Before treatment, mean hemoglobin values were 11.0 and 10.8 mg/dL in groups 1 and 2 respectively. After treatment hemoglobin values were 10.5 and 11.6 mg/dL respectively. Values were significantly decreased in group 1 (P=0.0001), whereas increased in group 2 (P=0.001). Adjustment for age and sex by ANCOVA confirmed the difference in hemoglobin levels between group (LS means-0.5 vs 0.8 in groups 1 and 2 respectively (P=0.0001). Hemoglobin level increases after antioxidant vitamin supplementation in children suffering from group A beta hemolytic streptococcal infection.