Supplemental Dietary Selenohomolanthionine Improve Antioxidant Activity and Immune Function in Weaned Beagle Puppies

Malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in canine serum: establishing reference intervals and influencing factors

BACKGROUND

Mounting evidence suggests that malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) are valuable biomarkers of lipid and nucleic acid oxidation in numerous canine diseases. However, their application in clinical settings is limited due to the absence of reference intervals (RI) and the analytical inconsistencies. Therefore, this study aimed to characterize serum MDA and 8-OHdG concentrations in dogs, to establish assay-specific RI, and to identify biological, haematological and biochemical factors influencing these markers.

METHODS

A total of 190 clinically healthy dogs were recruited, including pet dogs, working dogs and shelter dogs. Serum MDA concentration was measured by the Thiobarbituric Acid Reactive Substances (TBARS) assay, while 8-OHdG levels were determined by using a competitive ELISA. RI were established by non-parametric methods. Potential associations between oxidative stress (OS) biomarkers and multiple biological, haematological and biochemical factors were assessed using multivariate regression models.

RESULTS

RI for serum MDA (1.85-14.51 µM) and 8-OHdG (0.06-0.75 ng/mL) were established in the reference population (144 and 143 dogs, respectively). The multivariate regression model for MDA revealed a positive association with total cholesterol concentration, and a negative association with monocyte count. 8-OHdG level was positively associated with urea concentration. Notably, both models also revealed a significant association between MDA and 8-OHdG. Biological factors, including the age and size of the animals, did not exert a significant influence on the results.

CONCLUSIONS

This is the first study to establish serum RI for MDA and 8-OHdG in a large and diverse canine population. Additionally, the multivariate regression models identified relevant haematological and biochemical, but not biological factors that should be considered when interpreting the results. These findings could significantly enhance the application of MDA and 8-OHdG as biomarkers in clinical settings, and promote further exploration of their value in canine diseases.

Prognostic Roles of Trace Element and Cobalamin Concentrations in Dogs With Parvoviral Enteritis

BACKGROUND

The trace elements copper (Cu), zinc (Zn), and selenium (Se) have been the focus of research into their potential roles in the prognosis of gastrointestinal disorders in humans.

OBJECTIVE

Evaluation of the predictive potential serum concentrations of Cu, Zn, Cu/Zn, Se, and cobalamin as possible prognostic indicators in dogs with parvoviral enteritis (CPV).

ANIMALS

Client-owned dogs diagnosed with CPV (n = 20) and healthy controls (n = 10).

METHODS

A case-controlled study. Serum concentrations of Cu and Zn were measured using a spectrophotometric method; serum Se levels were determined by mass spectrophotometry; and serum cobalamin concentrations were assessed using a chemiluminescent immunoassay method. The Mann-Whitney U test was employed to compare subgroup medians.

RESULTS

Upon admission, surviving dogs with CPV (n = 10) exhibited higher serum Cu concentrations (median = 154.24; range = 60.15-188.46 μg/dL) and Cu/Zn ratios (median = 1.52; range = 0.67-2.45), alongside lower serum Zn concentrations (median = 88.05; range = 51.3-129.2 μg/dL) and cobalamin levels (median = 252.5; range = 111-396 pg/mL), compared to the control group (Cu, median = 72.12; range = 47.04-90.26 μg/dL), Zn (median = 184.2; range = 73.0-262.7 μg/dL), Cu/Zn (median = 0.37; range = 0.26-0.73), cobalamin (median = 638.5; range = 306.0-1016 pg/mL). Additionally, non-surviving dogs (n = 10) exhibited markedly higher serum Cu concentrations (median = 193.5; range = 125.0-229.0 μg/dL) and Cu/Zn ratios (median = 5.45; range = 1.95-9.23), and significantly lower serum Zn (median = 37.75; range = 24.8-71.6 μg/dL), Se (median = 52.45; range = 21.27-91 μg/L), and cobalamin levels (median = 52.2; range = 20.0-147.0 pg/mL) compared to both survivors and controls.

CONCLUSIONS AND CLINICAL IMPORTANCE

Statistical variations in serum concentrations of Cu, Zn, and cobalamin, alongside Cu/Zn ratios, were observed among survivors, non-survivors, and controls (control-survivor and survivor-non-survivor: p < 0.05 and control-non-survivor: p < 0.01), which might suggest their potential prognostic value in CPV.

Vitamins, Minerals and Phytonutrients as Modulators of Canine Immune Function: A Literature Review

Trends in the pet food industry are driven by the humanization of pets, favoring the inclusion of functional ingredients or supplements that promote animal health. Several commercial diets claim to include supplements with benefits for dogs' immune function, but in vivo evidence that supports their efficacy remains limited. This literature review aimed to better understand the current knowledge on the effects of vitamins, minerals and phytonutrients on dogs' immune function. A total of 27 peer-reviewed articles were identified in PubMed and Web of Science databases. Although vitamin supplementation is often claimed to support immune function, only two studies promoting slight benefits of vitamins C and E were found. The limited research on minerals suggests that organic sources promote a better immune response. Studies evaluating the inclusion of different phytonutrients show that these compounds might exert immunomodulatory and anti-inflammatory effects. Despite the increased popularity of commercial diets claimed to support the immune response of dogs, further research is needed in order to substantiate their effects. This knowledge will contribute to the development of effective diets to enhance immune health in dogs.

De novo assembly and characterization of the transcriptome of Morchella esculenta growth with selenium supplementation

Although Morchella esculenta (L.) Pers. is an edible and nutritious mushroom with significant selenium (Se)-enriched potential, its biological response to selenium stimuli remains unclear. This study explored the effect of selenium on mushroom growth and the global gene expression profiles of M. esculenta. While 5 µg mL-1selenite treatment slightly promoted mycelia growth and mushroom yield, 10 µg mL-1significantly inhibited growth. Based on comparative transcriptome analysis, samples treated with 5 µg mL-1 and 10 µg mL-1 of Se contained 16,061 (452 upregulated and 15,609 downregulated) and 14,155 differentially expressed genes (DEGs; 800 upregulated and 13,355 downregulated), respectively. Moreover, DEGs were mainly enriched in the cell cycle, meiosis, aminoacyl-tRNA biosynthesis, spliceosome, protein processing in endoplasmic reticulum pathway, and mRNA surveillance pathway in both selenium-treated groups. Among these, MFS substrate transporter and aspartate aminotransferase genes potentially involved in Se metabolism and those linked to redox homeostasis were significantly upregulated, while genes involved in isoflavone biosynthesis and flavonoid metabolism were significantly downregulated. Gene expression levels increased alongside selenite treatment concentration, suggesting that high Se concentrations promoted M. esculenta detoxification. These results can be used to thoroughly explain the potential detoxification and Se enrichment processes in M. esculenta and edible fungi.

Birth weight, puppies' growth and health with limited-ingredient novel protein diet vs standard diet in late pregnancy

Great attention has been given in the last years to the protein source of dog food, and commercial limited-ingredient diets with a single protein are available also for late pregnancy. This work compared the effect of a fish-based limited ingredient diet (LID), and of a standard mixed-protein diet (Mixed), fed to the bitches from the last three weeks of pregnancy and to the puppies at weaning, on birth weight, growth and health of the puppies. From a breeder's records, the weight of 22 Lagotto Romagnolo (LR) and 10 Appenzeller Cattle Dog (ACD) bitches on the day of mating, and of their 199 puppies, were extracted. The effect of diet on puppies' weight on day 0, 6, 30 and 60 was analyzed, considering litter size and sex. The analyses were repeated on puppies' weights normalized on the relative dam's non-pregnant bodyweight. Birth weight was available for 146 puppies, 82 LR and 64 ACD. Median birth weight of LR puppies was 287.5 g (170-400 g); sex ratio was 1.11 (males/females, N = 80). Median birth weight of ACD puppies was 390 g (240-525 g); sex ratio 1.15 (males/females, N = 58). Diet did not significantly affect birth weight in both breeds; however, it showed a significant effect on normalized birth weights (LR, P = 0.016; ACD, P = 0.034), with higher values for LID. At day 30, ACD puppies showed significantly higher weights with the Mixed diet (P = 0.002), and, at day 60, diet significantly affected the normalized weight in both breeds (LR, P = 0.019; ACD, P = 0.001), with higher values for the Mixed type. LID may help the dam to invest the energy in the growth of her litter, however, the same diet resulted in lower puppies' weights around weaning, compared to the Mixed diet. Although our results should be confirmed with larger numbers of animals and more breeds, they set some points worth to be further investigated. The choice of a limited-ingredient single-protein diet can affect litter weight and weight at weaning. Whether, administered to dams and puppies, it can prevent later pathologies, like chronic gastrointestinal diseases or food allergies, is a field of research deserving full attention.

Selenium Speciation Analysis Reveals Improved Antioxidant Status in Finisher Pigs Fed L-Selenomethionine, Alone or Combined with Sodium Selenite, and Vitamin E

Conditions associated with selenium (Se) and/or vitamin E (VitE) deficiency are still being reported in high-yielding pigs fed the recommended amounts. Here, the dietary effects of Se source (sodium selenite, NaSe, 0.40 or 0.65 mg Se/kg; L-selenomethionine, SeMet, 0.19 or 0.44 mg Se/kg; a NaSe-SeMet mixture, SeMix, 0.44-0.46 mg Se/kg) and VitE concentration (27, 50-53 or 101 mg/kg) on the antioxidant status of finisher pigs were compared with those in pigs fed non-Se-supplemented diets (0.08-0.09 mg Se/kg). Compared to NaSe-enriched diets, SeMet-supplemented diets resulted in significantly (p < 0.0018) higher plasma concentrations of total Se (14-27%) and selenospecies (GPx3, SelP, SeAlb; 7-83%), significantly increased the total Se accumulation in skeletal muscles, myocardium, liver and brain (10-650%), and enhanced the VitE levels in plasma (15-74%) and tissues (8-33%) by the end of the 80-day trial, proving better Se distribution and retention in pigs fed organic Se. Injecting lipopolysaccharide (LPS) intravenously half-way into the trial provoked a pyrogenic response in the pigs followed by a rapid increase of inorganic Se after 5-12 h, a drastic drop of SeMet levels between 12 and 24 h that recovered by 48 h, and a small increase of SeCys by 24-48 h, together with a gradual rise of GPx3, SelP and SeAlb in plasma up to 48 h. These changes in Se speciation in plasma were particularly significant (0.0024 > p > 0.00007) in pigs receiving SeMet- (0.44 mg Se/kg, above EU-legislated limits) or SeMix-supplemented (SeMet and NaSe both at 0.2 mg Se/kg, within EU-legislated limits) diets, which demonstrates Se metabolism upregulation to counteract the LPS-induced oxidative stress and a strengthened antioxidant capacity in these pigs. Overall, a Se source combination (without exceeding EU-legislated limits) and sufficient VitE supplementation (≥ 50 mg/kg) improved the pigs' antioxidant status, while doubling the allowed dietary organic Se increased the Se in tissues up to sixfold without compromising the animal's health due to toxicity. This study renders valuable results for revising the current dietary SeMet limits in swine rations.

Modulation of the Functional State of Mouse Neutrophils by Selenium Nanoparticles In Vivo

This study aimed to discover the immunomodulatory effect of selenium nanoparticles (SeNPs) on the functional state of neutrophils in vivo. Intraperitoneal injections of SeNPs (size 100 nm) 2.5 mg/kg/daily to BALB/c mice for a duration of 7-28 days led to the development of an inflammatory reaction, which was registered by a significant increase in the number of neutrophils released from the peritoneal cavity, as well as their activated state, without additional effects. At the same time, subcutaneous injections of the same SeNPs preparations at concentrations of 0.1, 0.5, and 2.5 mg/kg, on the contrary, modulated the functional state of neutrophils depending on the concentration and duration of SeNPs administration. With the use of fluorescence spectroscopy, chemiluminescence, biochemical methods, and PCR analysis, it was found that subcutaneous administration of SeNPs (0.1, 0.5, and 2.5 mg/kg) to mice for a short period of time (7-14 days) leads to modification of important neutrophil functions (adhesion, the number of migrating cells into the peritoneal cell cavity, ROS production, and NET formation). The obtained results indicated the immunostimulatory and antioxidant effects of SeNPs in vivo during short-term administration, while the most pronounced immunomodulatory effects of SeNPs were observed with the introduction of a low concentration of SeNPs (0.1 mg/kg). Increase in the administration time of SeNPs (0.1 mg/kg or 2.5 mg/kg) up to 28 days led to a decrease in the adhesive abilities of neutrophils and suppression of the expression of mRNA of adhesive molecules, as well as proteins involved in the generation of ROS, with the exception of NOX2; there was a tendency to suppress gene expression pro-inflammatory factors, which indicates the possible manifestation of immunosuppressive and anti-inflammatory effects of SeNPs during their long-term administration. Changes in the expression of selenoproteins also had features depending on the concentration and duration of the administered SeNPs. Selenoprotein P, selenoprotein M, selenoprotein S, selenoprotein K, and selenoprotein T were the most sensitive to the introduction of SeNPs into the mouse organism, which indicates their participation in maintaining the functional status of neutrophils, and possibly mediated the immunomodulatory effect of SeNPs.