BACKGROUND:

Disturbed oxidant/antioxidant status is involved in pathogenesis of anemia in end stage renal disease. There is evidence that vitamin E supplementation can increase blood hemoglobin in chronically hemodialyzed patients. However, the interindividual variation in response to the supplementation has not been fully addressed.

METHODS:

24 chronically hemodialyzed patients were supplemented with vitamin E (400 IU/day) in a period of two months. They had already been treated with erythropoiesis stimulating agents (ESA) and iron on a long-term basis, which was continued during the study period. A group of 20 healthy volunteers served as control subjects. Complete blood count, general biochemistry assays, the redox status by total thiols, oxidative stress by reactive oxygen metabolites, antioxidant status by biological antioxidant potential, and vitamin E (α- and γ- tocopherol) were measured before the start of supplementation, one month and two months later.

RESULTS:

Overall, the vitamin E supplementation did not cause an increase of blood hemoglobin, hematocrit or red blood cells. However, 50 % of the patients with basal blood hemoglobin below 12.0 g/dL (N = 10) responded to the supplementation with its continuous increase. In addition, vitamin E exhibited a slight prooxidant effect only in the subgroup of patients with basal blood hemoglobin of ≥ 12.0 g/dL, two months after the start of supplementation (decreased total thiols: 300 ± 31 vs. 277 ± 36 µmol/L, p < 0.05; increased reactive oxygen metabolites: 183 ± 140 vs. 287 ± 112 CARR U, p > 0.05; decreased biological antioxidant potential: 2278 ± 150 vs. 2171 ± 126 µEq/L, p < 0.025), which coincided with their significantly increased serum α-tocopherol concentrations in comparison to the patients with basal blood hemoglobin below 12.0 g/dL (41.3 ± 7.2 vs. 59.9 ± 19.2 µmol/L, p < 0.025).

CONCLUSIONS:

When treated with ESA and iron on a long-term basis, the response to the vitamin E supplementation in chronically hemodialyzed patients is largely dependent on their basal blood hemoglobin and serum vitamin E concentrations.

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Commercial poultry production is associated with a range of stresses, including environmental, technological, nutritional, and internal/biological ones, responsible for decreased productive and reproductive performance of poultry. At the molecular level, most of them are associated with oxidative stress and damages to important biological molecules. Poultry feed contains a range of feed-derived and supplemented antioxidants and, among them, vitamin E is considered as the “headquarters” of the antioxidant defense network. It is well-established that dietary supplementation of selenium, vitamin E, and carotenoids can modulate antioxidant defenses in poultry. The aim of the present paper is to present evidence related to modulation of the antioxidant capacities in poultry by vitamin E. Using 3 model systems including poultry breeders/males, semen, and chicken embryo/postnatal chickens, the possibility of modulation of the antioxidant defense mechanisms has been clearly demonstrated. It was shown that increased vitamin E supplementation in the breeder’s or cockerel’s diet increased their resistance to various stresses, including high polyunsaturated fatty acids (PUFA), mycotoxin, or heat stress. Increased vitamin E supplementation of poultry males was shown to be associated with significant increases in α-tocopherol level in semen associated with an increased resistance to oxidative stress imposed by various external stressors. Similarly, increased vitamin E concentration in the egg yolk due to dietary supplementation was shown to be associated with increased α-tocopherol concentration in the tissues of the developing embryos and newly hatched chicks resulting in increased antioxidant defenses and decreased lipid peroxidation. Furthermore, increased vitamin E transfer from the feed to egg yolk and further to the developing embryo was shown to be associated with upregulation of antioxidant enzymes reflecting antioxidant system regulation and adaptation. The role of vitamin E in cell signaling and gene expression as well as in interaction with microbiota and maintaining gut health in poultry awaits further investigation.

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Induced cell fusion is a powerful method for production of hybridoma in biotechnology and cell vaccines in medical applications. Among different alternatives, physical methods have an advantage, as they do not require any additives. Among them electrofusion, an electroporation-based cell fusion method holds a great promise. Electric pulses cause cell membrane permeabilization and due to pore formation bring cell membrane into the fusogenic state. At the same time, however, they compromise cell viability. We used a train of 8 × 100 µs electric pulses, delivered at 1 Hz with strengths ranging from 400 to 1600 V/cm. We evaluated electrofusion efficiency by dual color microscopy. We determined cell viability, because during electroporation reactive oxygen species are generated affecting cell survival. The novelty of our study is evaluation of the effect of lipid antioxidant α-tocopherol on cell fusion yield and cell viability on mouse B16-F1 cells. Pretreatment with α-tocopherol slowed down dynamic of cell fusion shortly after electroporation. Twenty-four hours later, fusion yields between α-tocopherol treated and untreated cells were comparable. The viability of α-tocopherol pretreated cells was drastically improved. Pretreatment of cells with α-tocopherol improved whole electrofusion process by more than 60%. We believe that α-tocopherol holds great promise to become an important agent to improve cell electrofusion method.

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