Supplemental L-arginine and vitamins E and C preserve xanthine oxidase activity in the lung of broiler chickens grown under hypobaric hypoxia

Arginine attenuates chronic mountain sickness in rats via microRNA-144-5p

Hypobaric hypoxia is an environmental stress leading to high-altitude pulmonary hypertension. While high-altitude pulmonary hypertension has been linked to high hematocrit findings (chronic mountain sickness; CMS). The present study is designed to investigate the effect of arginine (ARG) on hypobaric hypoxia-induced CMS of rats. Hypobaric hypoxia resulted in lower body weight, decreased appetite, increased pulmonary artery pressure, and deteriorated lung tissue damage in rats. Red blood cells (RBC), hemoglobin, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin values and blood viscosity were increased in rats, which were alleviated by ARG. microRNA (miRNA) microarray analysis was used to filter differentially expressed miRNAs after ARG in rats. miR-144-5p was reduced under hypobaric hypoxia and upregulated by ARG. miR-144-5p silencing aggravated the erythrocytosis and hyperviscosity in rats, and also accentuated tissue damage and excessive accumulation of RBC. The role of miR-144-5p in rats with CMS was achieved by blocking erythropoietin (EPO)/erythropoietin receptor (EPOR). In conclusion, ARG alleviated CMS symptoms in rodents exposed to hypobaric hypoxia by decreasing EPO/EPOR via miR-144-5p.

The inhibitory kinetics of vitamins B9, C, E, and D3 on bovine xanthine oxidase: Gout treatment

BACKGROUND

Over-consumption of foods high in purines like seafood, red meat, and alcoholic beverages leads to hyperuricemia causing gout attacks. Xanthine oxidase was reported responsible for the overproduction of uric acid.

MATERIAL AND METHODS

We intend to test in silico and in vitro, the inhibition effect of four vitamins against bovine milk xanthine oxidase (BXO). We performed Molecular docking with GOLD v4.0, and the biological activity prediction with the PASS server. The best-selected vitamins were chosen based on their best PLPchem score. The BXO constant K_m and V_max were determined in vitro, and then the vitamins were tested for their inhibition effect to BXO. Furthermore, the inhibition constant Ki of each inhibitor were determined using Dixon method, the vitamins chosen were vitamin E, vitamin B9, vitamin D3, and vitamin C.

RESULTS

The in silico results show that the tested vitamins were the best inhibitors model with PLPchem scores up to 70 comparing to the control. The in vitro results show that BXO have a K_m value of 163.55 μM with V_max of 37 U, vitamins B9, E, C, and D3 were potent inhibitors to BXO with an IC50 of 34.10 ± 0.21, 36.68 ± 1.50, 39.01 ± 0.02, and 100.28 ± 0.33 μM, respectively comparing to the control (32.03 ± 0.73 μM). The kinetic study shows that all tested vitamins were Non-competitive inhibitors, the Ki values were 15 ± 1.76 μM, 29 ± 1.06 μM, 12 ± 1.41 μM, and 20 ± 0.71 μM, for respectively vitamins B9, E, C, and D3.

CONCLUSION

The obtained results promise an excellent strategy using vitamins to enhance immunity, treat hyperuricemia, and minimize the usual drug side effects.

Selection scan reveals three new loci related to high altitude adaptation in Native Andeans

The Andean Altiplano has been occupied continuously since the late Pleistocene, ~12,000 years ago, which places the Andean natives as one of the most ancient populations living at high altitudes. In the present study, we analyzed genomic data from Native Americans living a long-time at Andean high altitude and at Amazonia and Mesoamerica lowland areas. We have identified three new candidate genes - SP100, DUOX2 and CLC - with evidence of positive selection for altitude adaptation in Andeans. These genes are involved in the TP53 pathway and are related to physiological routes important for high-altitude hypoxia response, such as those linked to increased angiogenesis, skeletal muscle adaptations, and immune functions at the fetus-maternal interface. Our results, combined with other studies, showed that Andeans have adapted to the Altiplano in different ways and using distinct molecular strategies as compared to those of other natives living at high altitudes.

Interactive effects of temperature and dietary supplementation of arginine or guanidinoacetic acid on nutritional and physiological responses in male broiler chickens

1. The aim of this experiment was to study the interactive effect of rearing temperature and dietary supplementation of arginine (Arg) or guanidinoacetic acid (GAA) on performance, gut morphology and ascites indices in broiler chickens raised under the same condition in the first 2 weeks and then reared under normal (23-26°C) or subnormal (17°C) ambient temperatures for the next 3 weeks. 2. This experiment was conducted as a split plot with 900 Ross 308 male broiler chicks that were allocated to two houses (as main plots); each consisted of 5 treatments (as sub-plots) with 6 replicates of 15 birds. The 5 diets were (1) control, (2) control + 0.60 g/kg GAA, (3) control + 1.20 g/kg GAA, (4) control + 0.86 g/kg Arg and (5) control + 1.72 g/kg Arg. 3. Feed intake (0-35 d) of birds fed on a diet containing 1.2 g GAA/kg and reared under normal temperature was reduced compared to control fed birds. Birds fed on a diet containing 1.72 g/kg Arg and reared under subnormal temperature had higher weight gain compared to those fed on control or GAA-added diets in overall study period. 4. Supplementation of diets with Arg alleviated the adverse effect of cold stress as reflected by reduction in blood haematocrit (41% vs. 37%), and right ventricle to total ventricle ratio (0.28 vs. 0.25) at 35 d of age. Addition of Arg to the diet of birds reared under cold stress resulted in a higher jejunal villus surface area compared to those fed on control or GAA-added diets. 5. Findings of this study revealed that Arg or GAA supplementation of diets did not affect performance of birds under normal temperatures, but Arg supplementation of the diet significantly alleviated the adverse effect of cold stress on performance, gut development and ascites syndrome. In addition, GAA supplementation at 1.2 g/kg improved jejunal villus surface area in birds raised under subnormal temperature.

Concurrent supplementation of arginine and antioxidant vitamins E and C reduces oxidative stress in broiler chickens after a challenge withEimeriaspp

Dominguez P.A., Pro-Martinez, A., Narciso-Gaytán, C., Hernández-Cázares, A., Sosa-Montes, E., Perez-Hernandez, P., Caldwell, D. and Ruiz-Feria, C. A. 2015. Concurrent supplementation of arginine and antioxidant vitamins E and C reduces oxidative stress in broiler chickens after a challenge with Eimeria spp. Can. J. Anim. Sci. 95: 143–153. Oxidation is a major problem associated with pathogen damage in animals. One-day-old mixed-sex broiler chicks (Cobb 500; n=624) were randomly assigned to one of six treatments: a basal diet [CTL; 40 mg of vitamin E (VE) kg−1of feed and 1.5% Arginine (Arg)] or the basal diet plus Arg (ARG; 0.3%), Arg+VE (AVE; 0.3% and 40 mg kg−1respectively), Arg+vitamin C (VC) (AVC; 0.3% and 1 g kg−1respectively), VE+VC (VEC; 40 mg+1 g kg−1respectively), or Arg+VE+VC (AVEC; 0.3%+40 mg+1 g kg−1respectively). At day 14, all birds were orally challenged with 100× the normal dose of Advent®coccidiosis vaccine (450 000 oocysts). Intestinal lesion scores (LS) in duodenum, jejunum and ceca were recorded, along with relative immune system organ weights at day 23. Plasma samples were taken before (2 h) and after challenge (12, 24 and 48 h) to determine malondialdehyde (MDA), nitric oxide (NO) and glutathione peroxidase activity (GPx). Birds fed the VEC diet were heavier at 7 d (P<0.05) than birds fed the AVE diet. CTL birds had heavier (P<0.05) bursas than AVC birds; no differences among treatments for spleen and thymus were found. The jejunum LS was lower in the AVC and VEC birds than in CTL birds, whereas ceca LS was highest in AVE birds, and the duodenum LS was not affected by treatment. Birds fed the AVEC diet had the lowest MDA levels before challenge, but higher levels of MDA than birds fed the CTL, ARG or AVE 12 h after challenge. Before challenge ARG birds had higher (P<0.05) NO levels than AVEC-fed birds, but 12 h after challenge birds fed the CTL, ARG or AVE diet had lower NO levels than birds fed the AVC, VEC or AVEC diet. Before challenge AVEC-fed birds had higher (P<0.001) GPx activity than CTL, ARG and AVE birds, but after 12, 24 and 48 h VEC birds showed higher GPx activity than CTL, ARG- and AVE-fed birds. Although Arg, VE and VC, modulated oxidative stress during coccidiosis challenge, the effects were not sufficient to affect performance relative to the control diet.

Synthesis of Au/graphene oxide composites for selective and sensitive electrochemical detection of ascorbic acid

In this work, we present a novel ascorbic acid (AA) sensor applied to the detection of AA in human sera and pharmaceuticals. A series of Au nanoparticles (NPs) and graphene oxide sheets (Au NP/GO) composites were successfully synthesized by reduction of gold (III) using sodium citrate. Then the Au NP/GO composites were used to construct nonenzymatic electrodes in practical AA measurement. The electrode that has the best performance presents attractive analytical features, such as a low working potential of +0.15 V, a high sensitivity of 101.86 μA mM(-1) cm(-2) to AA, a low detection limit of 100 nM, good reproducibility and excellent selectivity. And more,it was also employed to accurately and practically detect AA in human serum and clinical vitamin C tablet with the existence of some food additive. The enhanced AA electrochemical properties of the Au NP/GO modified electrode in our work can be attributed to the improvement of electroactive surface area of Au NPs and the synergistic effect from the combination of Au NPs and GO sheets. This work shows that the Au NP/GO/GCEs hold the prospect for sensitive and selective determination of AA in practical clinical application.