The effect of trace minerals on the stability of retinol acetate, cholecalciferol and selenomethionine stability within premixes

This study compared the effect of an organic proteinate mineral source and an inorganic sulphate mineral source in relation to their effect on the stability of retinol acetate and cholecalciferol within simulated premixes, while comparing the stability of two different selenomethionine (SeMet) sources (selenium enriched yeast (SeYeast) and the chemically synthesised L-SeMet) in the presence of inorganic sulphate mineral sources within simulated premixes. Four vitamin-trace mineral premixes, two containing organic trace mineral sources in the form of proteinates and two containing inorganic trace mineral sources in the form of sulphates, were formulated so that, when added to a complete broiler feed at the appropriate inclusion rates, they contained the same amount of retinol acetate and cholecalciferol and varying levels of trace minerals (National Research Council recommended level, commonly used industry level or a reduced inclusion level). The two SeMet-trace mineral premixes were formulated to contain commonly used industry levels of vitamins and trace minerals. The two SeMet-trace mineral premixes differed in the source of SeMet. One premix contained chemically synthesised L-SeMet while the other contained SeYeast. The vitamin content of the four vitamin-trace mineral premixes was analysed after 14 and 84 days in storage by ultra-high performance liquid chromatography and the amount present within each of the premixes was compared to the quantity determined prior to storage. In general, the premixes formulated with the sulphate trace mineral source were found to have higher losses of retinol acetate and cholecalciferol than those formulated with the proteinate trace mineral source. The inclusion of the proteinate minerals at both National Research Council and reduced inclusion levels significantly (P≤0.05) increased the stability of both the vitamins when compared to the inorganic sulphate mineral sources included at commonly used industry levels. The SeMet content of the two SeMet-trace mineral premixes was analysed after 49 days in storage by high performance liquid chromatography – inductively coupled plasma mass spectrometry and the amount of SeMet present within each of the samples was compared to the quantity determined prior to storage. SeMet present within the SeYeast was found to be significantly more stable (P≤0.05) than the chemically synthesised L-SeMet.

Regulation of the microecological state of the lower parts of the female reproductive tract with vitamins

Aim. To study the changes in the microecology of the vagina under the influence of ascorbic acid, α-tocopherol, and retinol acetate.Materials and methods. The number of vaginal lactobacilli and opportunistic bacteria, the concentrations of IL1β, raIL1, INFγ, TGFβ1, lactoferrin and sIgA in vaginal fluids of women with deficiency of ascorbic acid (n = 35) or retinol acetate (n = 35) or α-tocopherol (n = 35) were assessed before and after intravaginal application of these vitamins. The obtained data were compared with those of healthy women without vitamin deficiency (n = 15).Results. An association between deficiency of α-tocopherol, retinol acetate and ascorbic acid with a deficiency of lactoflora, a high frequency of bacterial vaginosis and candidiasis, and proinflammatory changes of the parameters of mucosal immunity has been found. A normalizing effect of all vitamins on the lactoflora of the vagina was identified. The severity of this effect decreased in the following order: α-tocopherol → retinol acetate → ascorbic acid. Retinol acetate caused the increase, while ascorbate and tocopherol caused the reduction in the number of opportunistic microorganisms. The effect of ascorbate was pronounced, but short-term, while the effect of tocopherol was less pronounced, but long-lasting. The use of vitamins affected the condition of mucosal immunity in different directions: ascorbic acid caused an increase in pro-inflammatory changes; on the contrary, α-tocopherol and retinol acetate caused anti-inflammatory changes.Conclusion. Our data on the effects of α-tocopherol, retinol acetate, and ascorbic acid on the microecological state of the vaginal biotope suggest that these vitamins may be considered as regulatory factors for both host cells and microsymbionts.

Inhibitory effect of retinol acetate on horseradish peroxidase

Primary role of peroxidase enzyme is to decompose endogenous hydrogen peroxide, when oxygen radical is being replaced by a less potent radical, which is its cosubstrates oxidized form. During this study, catalytic activity of horseradish peroxidase has been observed in the presence of antioxidants from vitamin group, such as C, E and A, i.e. their water-soluble forms. It was found that vitamin E showed no effect on the enzyme activity and fate of cosubstrate radicals from the group of benzidine derivatives. Vitamin C proceeds enzymatic reaction showing its antioxidative character, and absorbs electrons from radicals, bringing cosubstrate back to its relaxed state. On the other hand, vitamin A plays a role of uncompetitive peroxidase inhibitor, which is visible through decreasing initial rate of catalytic reaction, and is reflected as virtual decrease of enzyme concentration. Furthermore, it prolongs life of endogenous hydrogen peroxide, which could potentially lead to oxidative stress of cells. This inhibitory effect can be used in analytical purpose, for determination of retinol acetate content in a sample.