Low circulating levels of total and free 25-hydroxyvitamin D (25(OH)D) indicative of vitamin D status have been associated with obesity in humans. Moreover, obesity is thought to play a causal role in the reduction of 25(OH)D levels, and several theories have been put forward to explain this relationship. Here we tested the hypothesis that obesity disrupts vitamin D homeostasis in key organs of vitamin D metabolism. Male C57BL6 mice were fed for 7 or 11 weeks on either a control diet (control, 10% energy from fat) or a high-fat diet (HF, 60% energy from fat) formulated to provide equivalent vitamin D3 intake in both groups. After 7 weeks, there was a transient increase of total 25(OH)D together with a significant decrease of plasma vitamin D3 that could be related to the induction of hepatic genes involved in 25-hydroxylation. After 11 weeks, there was no change in total 25(OH)D but a significant decrease of free 25(OH)D and plasma vitamin D3 levels. We also quantified an increase of 25(OH)D in adipose tissue that was inversely correlated to the free 25(OH)D. Interestingly, this accumulation of 25(OH)D in adipose tissue was highly correlated to the induction of Cyp2r1, which could actively participate in vitamin D3 trapping and subsequent conversion to 25(OH)D in adipose tissue. Taken together, our data strongly suggest that the enzymes involved in vitamin D metabolism, notably in adipose tissue, are transcriptionally modified under high-fat diet, thus contributing to the obesity-related reduction of free 25(OH)D.

This study is aimed at comparing the bio-efficacy of different inorganic and organic Se compounds. Three broiler experiments (Exp1 ¼ Ross PM3; Exp2 ¼ Ross 308; and Exp3 ¼ Ross 308) were performed, on the basis of Se tissue accretion, to define the bio-efficacy of Se sources. Birds were fed a control diet (negative control [NC]; no supplemental Se) and, depending on the study, the NC was supplemented with sodium selenite (SS), Se-yeast (35%, 56%, 65% or 72% of Se as selenomethionine (SeMet); SY35, SY56, SY65 and SY72), pure forms of selenocysteine (SeCys) (methylselenocysteine [MSeCys]; L-selenocystine [L-SeCys]), or pure form of organic Se (L-selenomethionine, L-SeMet or hydroxy-selenomethionine, OH-SeMet) at 0.3 mg Se/kg. In Exp 2, an additional treatment of SY65 þ L-SeCys was also fed, with both sources added at 0.3 mg Se/kg. In Exp3, L-SeMet and OH-SeMet, were supplemented at 0.15, 0.30, 0.45 and 0.60 mg Se/kg. The results of Exp 1 (mg Se/kg muscle DM

The role of 2-hydroxy-(4-methylseleno)butanoic acid (OH-SeMet), a form of organic selenium (Se), in selenoprotein synthesis and inflammatory response of THP1-derived macrophages stimulated with lipopolysaccharide (LPS) has been investigated. Glutathione peroxidase (GPX) activity, GPX1 gene expression, selenoprotein P (SELENOP) protein and gene expression, and reactive oxygen species (ROS) production were studied in Se-deprived conditions (6 and 24 h). Then, macrophages were supplemented with OH-SeMet for 72 h and GPX1 and SELENOP gene expression were determined. The protective effect of OH-SeMet against oxidative stress was studied in H2O2-stimulated macrophages, as well as the effect on GPX1 gene expression, oxidative stress, cytokine production (TNFα, IL-1β and IL-10), and phagocytic and killing capacities after LPS stimulation. Se deprivation induced a reduction in GPX activity, GPX1 gene expression, and SELENOP protein and gene expression at 24 h. OH-SeMet upregulated GPX1 and SELENOP gene expression and decreased ROS production after H2O2 treatment. In LPS-stimulated macrophages, OH-SeMet upregulated GPX1 gene expression, enhanced phagocytic and killing capacities, and reduced ROS and cytokine production. Therefore, OH-SeMet supplementation supports selenoprotein expression and controls oxidative burst and cytokine production while enhancing phagocytic and killing capacities, modulating the inflammatory response, and avoiding the potentially toxic insult produced by highly activated macrophages.

In order to increase the economic profitability of Avileña-Negra Ibérica beef production, the inclusion of corn silage in total mixed rations was proposed during the fattening period. Twenty-four Avileña-Negra Ibérica breed entire young bulls were used to evaluate the effects of two feeding systems—concentrate (CON) and corn silage (SIL)—and two packaging systems—vacuum (VAC) and modified atmosphere (MAP)—on the lipid oxidation, color evolution and visual color acceptability of meat throughout display with either oxygen-permeable film (FILM) or modified atmosphere (MAP). Two muscles were assessed: Longissimus thoracis (LT) and Semitendinosus (ST). Meat from SIL-fed animals had higher TBA values than CON-fed animals after 7 days in MAP packaging. Lipid oxidation was prevented more effectively by VAC packaging than MAP. Display time highly influenced lipid oxidation, since oxidation rates were lower with VAC than MAP packaging. After 14 days of display in MAP, the LT from CON was lighter than the ST. Meat discoloration after 7 days of display was significantly different between packaging systems. Vacuum-packaged meat kept the same color throughout the storage time. Visual color acceptability for the LT was higher throughout display than for the ST. Samples from the MAP were well accepted by consumers, especially the meat from the SIL group. Alternatively, feeding with corn silage could be used for this type of animals without affecting important aspects of meat quality.