Minimization of free radical damage by metal catalysis of multivitamin/multimineral supplements

Degradation kinetics of vitamins in premixes for pig: effects of choline, high concentrations of copper and zinc, and storage time

OBJECTIVE

The present work was undertaken to evaluate the effects of storage time, choline chloride, and high concentrations of Cu and Zn on the kinetic behavior of vitamin degradation during storage in two vitamin premixes and four vitamin-trace mineral (VTM) premixes.

METHODS

Two vitamin premixes (with or without 160,000 mg/kg of choline) were stored at 25°C and 60% humidity. Besides, four VTM premixes were used to evaluate the effects of choline (0 vs 40,000 mg/kg) and trace minerals (low CuSO4+ZnO vs high CuSO4+ZnO) on vitamin stability in VTM premixes stored in room, and the VTM premixes were stored in room temperature at 22°C. Subsamples from each vitamin and VTM premix were collected at 0, 1, 2, 3, 6, and 12 months. The retention of vitamin A (VA), vitamin D3 (VD3), vitamin E (VE), vitamin K3 (VK3), vitamin B1 (VB1), vitamin B2 (VB2), vitamin B3 (VB3), vitamin B5 (VB5), and vitamin B6 (VB6) in vitamin premixes and VTM premixes during storage was determined. The stability of vitamins in vitamin premixes and VTM premixes was determined and reported as the residual vitamin activity (% of initial) at each sampling point.

RESULTS

The effect of choline on VK3 retention was significant in vitamin premixes (p<0.05). The negative effect of storage time was significant for the retentions of VD3, VK3, VB1, VB2, VB5, and VB6 in vitamin premix (p<0.05). For VTM premixes, negative effect of storage time was significant (p<0.05) for the losses of vitamin in VTM premixes. Choline and high concentrations of Cu and Zn significantly increased VA, VK3, VB1, and VB2 loss during storage (p<0.05). The supplementation of high concentrations of Cu and Zn significantly decreased the concentrations of VD3 and VB6 (p<0.05) in VTM premixes at extended storage time.

CONCLUSION

The maximum vitamin stability was detected in vitamin and VTM premixes containing no choline or excess Cu and Zn. The results indicated that extended storage time increased degradation of vitamin in vitamin or VTM premixes. These results may provide useful information for vitamin and VTM premixes to improve the knowledge of vitamin in terms of its stability.

Combined efficacy of oseltamivir, isoprinosine and ellagic acid in influenza A(H3N2)-infected mice

Influenza pathogenesis comprises a complex cascade of impaired cellular processes resulting from the viral replication and exaggerated immune response accompanied by reactive oxygen species (ROS) burst and oxidative stress, destructing membranous structures and tissues. By classical virological and biochemical methods we compared and evaluated the therapeutic effects of 2.5mg/kg/day of the antiviral drug - oseltamivir (OS), 500mg/kg/day of the immune modulator - isoprinosine (IP) and 500mg/kg/day of the antioxidant agent ellagic acid (EA) with a focus on their combined activities in influenza H3N2 virus-infected mice. The survival, lung pathology and titers, as well as the oxidative stress biomarker thiobarbituric acid reactive substances (TBARS) in the lungs, liver and blood plasma, correlated to the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione reductase (GR) were assessed. We found that the viral inhibitor applied together with the immune modulator and the antioxidant exhibited strong therapeutic effects on the survival of the influenza-challenged mice. That effect was mostly pronounced for the triple combination - protection index (PI) of 75.2%, mean survival time (MST) extended by 5.8 days compared to the PBS control and significant reduction of the lung titers by 1.38 Δlg; 2.3 scores lower lung pathology and 8 times reduction of the accumulated TBARS in the lungs and liver on the 5^-th day p.i. The enzymatic assays revealed that this combination demonstrated very good protection against the damaging superoxide radicals (83% efficiency of SOD, in comparison to healthy controls 100%). The double combinations of OS with IP and EA also showed protective effects according to the virological analysis - PI of 53.1% and 54.5%. Ten times higher GR activity was observed when the combination EA+OS and monotherapy of EA were applied (96% in comparison to healthy controls 100%). The best antioxidant effect in blood plasma was observed in the EA+IP group - 4 times reduction in the TBARS-content compared to infected controls but it did not have any efficacy on the survival and lung injury.

In vivo imaging of free radicals produced by multivitamin-mineral supplements

Background

Redox active minerals in dietary supplements can catalyze unwanted and potentially harmful oxidations.

Methods

To determine if this occurs in vivo we employed electron paramagnetic (EPR) imaging. We used 1-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine (CPH) as a reporter for one-electron oxidations, e.g. free radical-mediated oxidations; the one-electron oxidation product of CPH, 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (CP^•), is a nitroxide free radical that is relatively persistent in vivo and detectable by EPR. As model systems, we used research formulations of vitamin mineral supplements (RVM) that are typical of commercial products.

Results

In in vitro experiments, upon suspension of RVM in aqueous solution, we observed: (1) the uptake of oxygen in the solution, consistent with oxidation of the components in the RVM; (2) the ascorbate free radical, a real-time indicator of ongoing oxidations; and (3) when amino acid/oligosaccharide (AAOS; glycinate or aspartate with non-digestible oligofructose) served as the matrix in the RVM, the rate of oxidation was significantly slowed. In a murine model, EPR imaging showed that the ingestion of RVM along with CPH results in the one-electron oxidation of CPH by RVM in the digestive system. The resulting CP^• distributes throughout the body. Inclusion of AAOS in the RVM formulation diminished the oxidation of CPH to CP^• in vivo.

Conclusions

These data demonstrate that typical formulations of multivitamin/multimineral dietary supplements can initiate the oxidation of bystander substances and that AAOS-complexes of essential redox active metals, e.g. copper and iron, have reduced ability to catalyze free radical formation and associated detrimental oxidations when a part of a multivitamin/multimineral formulation.

Effect of dietary supplementation on the prognostic value of urinary and serum 8-isoprostaglandin F2α in chemically-induced mammary carcinogenesis in the rat

Backround

The aim of the present study was to assess the effects of zinc or copper and polyphenolic compounds on the 8-isoprostaglandin F_2α concentration in the serum and urine of rats with mammary cancer (adenocarcinoma) induced with 7,12-dimethylbenz[a]antracene. The research focused on the kinetics of alterations in urinary 8-isoPGF_2α at the early stage of carcinogenesis as well as the influence of dietary factors on the process. The impact of selected compounds on the intensity of DMBA - induced carcinogenesis was also assessed.

Result and conclusions

Administration of DMBA, a compound that inducers mammary tumors in experimental animals, increased the serum and urinary 8-isoPGF_2α levels in study rats. In the rat model, diet supplementation with zinc, combined with selected polyphenolic compounds (resveratrol or genistein) yielded a statistically significant decrease in the rat serum and urinary biomarker concentration with a simultaneously significant stimulation of carcinogenesis.

The results indicate that there is an inverse correlation between the intensity of DMBA-induced carcinogenicity and the level of 8-isoPGF_2α in urine and serum of rats.