Evaluation of the Neuroprotective Effect of Organic Selenium Compounds: An in Vitro Model of Alzheimer's Disease.

Selenium (Se) is an essential trace element for human health and plays an important role in the development and maintenance of central nervous system functions. Se deficiency has been associated with cognitive decline and increased oxidative stress. The increase in oxidative stress is one of the hypotheses for the emergence and worsening of neurodegenerative diseases, such as Alzheimer's disease (AD). To investigate the neuroprotective effects of organic Se compounds in human neuroblastoma cells (SH-SY5Y) differentiated into cholinergic neurons-like. The SH-SY5Y cells were differentiated into cholinergic neuron-like with retinoic acid (RA) and brain-derived neurotrophic factor (BDNF). AD was mimicked exposing the cells to okadaic acid (OA) and beta-amyloid protein (Aß). The neuroprotective effect of organic Se compounds, selenomethionine (SeMet) and Ebselen, was evaluated through cell viability tests, acetylcholinesterase and antioxidant enzyme activities, and detection of reactive oxygen species (ROS). None of the SeMet concentrations tested protected against the toxic effect of OA + Aß. On the other hand, previous exposure to 0.1 and 1 µM Ebselen protected cells from the toxic effect of OA + Aß. Cell differentiation induced by RA and BDNF exposure was effective, showing characteristics of neuronal cells, and pointing to a promising model of AD. Ebselen showed a protective effect, but more studies are needed to identify the mechanism of action.

Effects of selenium supplementation on glycaemic control markers in healthy rodents: a systematic review and meta-analysis.

Overexposure to Se is detrimental to glucose metabolism, mainly because of its pro-oxidant effects and the overexpression of selenoproteins. This systematic review evaluated the effects of Se supplementation on glycaemic control in healthy rodents. The methodology followed the PRISMA. We searched the databases for articles published up to May 2022. The risk of bias and the methodological quality were assessed using the SYRCLE and CAMARADES. The results are presented as meta-analytic estimates of the overall standardised mean difference (SMD) and 95 % CI. Of the 2359 records retrieved, thirteen studies were included, of which eleven used sodium selenite and two used zero-valent Se nanoparticles as supplement. Nine studies were included in the meta-analysis. Generally, the risk of bias was high, and 23·1 % of the studies were of high quality. Supplementation with sodium selenite significantly increased fasting blood glucose (SMD = 2·57 (95 % CI (1·07, 4·07)), I2 = 93·5 % (P = 0·001). Subgroup analyses showed effect size was larger for interventions lasting between 21 and 28 d (SMD = 25·74 (95 % CI (2·29, 9·18)), I2 = 96·1 % (P = 0·001)) and for a dose of 864·7 µg/kg/d of sodium selenite (SMD = 10·26 (95 % CI (2·42, 18·11), I2 = 97·1 % (P = 0·010)). However, it did not affect glutathione peroxidase activity (SMD = 0·60 (95 % CI (-0·71, 1·91)), I2 = 83·2 % (P = 0·37)). The current analysis demonstrated the adverse effects of sodium selenite supplementation on glycaemic control in healthy rodents.

Impact of Selenium-Supplemented Diets on Egg Morphometry and Quality in Four Varieties of Indigenous Aseel Chicken

The present study aimed at evaluating the effects of dietary selenium (Se) supplementation on egg morphometric and quality traits in Aseel chicken. In total, 84 adult molted Aseel hens, comprising 4 varieties (Lakha, Mushki, Peshawari, and Mianwali), were divided into 3 dietary treatments (organic at 0.30 ppm, inorganic at 0.30 ppm, and without selenium) with 7 replicates (1 bird in each) under randomized complete block design. Data were analyzed using factorial ANOVA and means were compared using Duncan’s Multiple Range Test. The results indicated greater egg length in Mushki and Mianwali, lower egg breadth in Lakha, the highest (p≤0.05) egg volume and surface area in Mianwali, and higher shape index in Lakha and Peshawari. Lakha had the highest Haugh unit and lower eggshell thickness with and without membrane than the other three varieties. Interaction of Se sources and Aseel varieties exhibited the highest (p≤0.05) egg volume and surface area in Mianwali variety when fed on organic Se supplemented diet. Similarly, the interaction showed the highest eggshell thickness with membrane in Peshawari and without membrane in Mianwali when fed on inorganic Se supplemented diet. From the findings, it can be concluded that egg physical characteristics of Mianwali variety hens can be improved by the supplementation of Se-enriched yeast, as an organic Se source, in the diet.

Impact of Selenium-Supplemented Diets on Egg Morphometry and Quality in Four Varieties of Indigenous Aseel Chicken

ABSTRACT The present study aimed at evaluating the effects of dietary selenium (Se) supplementation on egg morphometric and quality traits in Aseel chicken. In total, 84 adult molted Aseel hens, comprising 4 varieties (Lakha, Mushki, Peshawari, and Mianwali), were divided into 3 dietary treatments (organic at 0.30 ppm, inorganic at 0.30 ppm, and without selenium) with 7 replicates (1 bird in each) under randomized complete block design. Data were analyzed using factorial ANOVA and means were compared using Duncans Multiple Range Test. The results indicated greater egg length in Mushki and Mianwali, lower egg breadth in Lakha, the highest (p0.05) egg volume and surface area in Mianwali, and higher shape index in Lakha and Peshawari. Lakha had the highest Haugh unit and lower eggshell thickness with and without membrane than the other three varieties. Interaction of Se sources and Aseel varieties exhibited the highest (p0.05) egg volume and surface area in Mianwali variety when fed on organic Se supplemented diet. Similarly, the interaction showed the highest eggshell thickness with membrane in Peshawari and without membrane in Mianwali when fed on inorganic Se supplemented diet. From the findings, it can be concluded that egg physical characteristics of Mianwali variety hens can be improved by the supplementation of Se-enriched yeast, as an organic Se source, in the diet.

Impact of Selenium-Supplemented Diets on Egg Morphometry and Quality in Four Varieties of Indigenous Aseel Chicken

The present study aimed at evaluating the effects of dietary selenium (Se) supplementation on egg morphometric and quality traits in Aseel chicken. In total, 84 adult molted Aseel hens, comprising 4 varieties (Lakha, Mushki, Peshawari, and Mianwali), were divided into 3 dietary treatments (organic at 0.30 ppm, inorganic at 0.30 ppm, and without selenium) with 7 replicates (1 bird in each) under randomized complete block design. Data were analyzed using factorial ANOVA and means were compared using Duncans Multiple Range Test. The results indicated greater egg length in Mushki and Mianwali, lower egg breadth in Lakha, the highest (p≤0.05) egg volume and surface area in Mianwali, and higher shape index in Lakha and Peshawari. Lakha had the highest Haugh unit and lower eggshell thickness with and without membrane than the other three varieties. Interaction of Se sources and Aseel varieties exhibited the highest (p≤0.05) egg volume and surface area in Mianwali variety when fed on organic Se supplemented diet. Similarly, the interaction showed the highest eggshell thickness with membrane in Peshawari and without membrane in Mianwali when fed on inorganic Se supplemented diet. From the findings, it can be concluded that egg physical characteristics of Mianwali variety hens can be improved by the supplementation of Se-enriched yeast, as an organic Se source, in the diet.(AU)

Selenium supplementation during pregnancy and lactation promotes metabolic changes in Wistar rats' offspring.

Epidemiological and animal studies have demonstrated a strong association between selenium (Se) supplementation and metabolic disorders, we aimed to evaluate whether maternal Se supplementation was able to change metabolic parameters in rats' offspring. Moreover, as Se is a deiodinase (DIO) cofactor, we decided to investigate how thyroid hormones (THs) would be involved in such metabolic changes. Thereby, two groups (n = 6, ~250 g) of female Wistar rats underwent isotonic saline or sodium selenite (1 mg/kg, p.o.) treatments. Although there were no significant differences in body weight between groups, the Se treatment during pregnancy and lactation increased milk intake and the visceral white adipose tissue (WAT) in offspring. The rats whose mothers were treated with Se also presented an improvement in the glucose tolerance test and in the glucose-stimulated insulin secretion. Regarding the lipid metabolism, the Se group had a reduction of triglycerides in the liver and in WAT. These metabolic changes were accompanied by an increase in serum triiodothyronine (T3 ) and in DIO 2 expression in brown adipose tissue (BAT). We further demonstrate an increased expression of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α) and nuclear respiratory factor-1 (NRF-1) mRNA in the liver. In adulthood offspring, Se supplementation programs thyroid function, glucose homeostasis, and feeding behaviour. Taken together, there is no indication that Se programming causes insulin resistance. Moreover, we conjecture that these metabolic responses are induced by increased thyroxine (T4 ) to T3 conversion by DIO2 in BAT and mediated by altered transcription factors expression associated with oxidative metabolism control in the liver.

Association between handling stress in the corral and rabies antibody titers in selenium-supplemented cattle

This study determined the correlation between serum cortisol levels and rabies antibody titers in cattle primo-vaccinated against rabies and supplemented with dietary selenium (Se). Sixty Nelore male calves (10 to 12 months old) received daily and individual dietary supplementation with 0, 3.6, 5.4 and 6.4 mg Se (groups Gc, G3.6, G5.4 and G6.4, respectively). The animals were vaccinated against rabies (day 0) and subjected to handling stress in the corral for 120 days. Blood sampling procedures were performed on days 0, 15, 30, 60, 90 and 120. Cortisol levels increased until day 90, but had dropped significantly by day 120 (P < 0.01). Rabies antibody titers on days 30 and 90 were similar among Se-supplemented groups; in the control group, rabies antibodies decreased significantly from day 30 to 60, and 90 to 120. Serum cortisol levels and antibody titers were not correlated in most of the groups or blood sampling days. A positive correlation among these variables was found only in G6.4 on days 60 (R = 0.513; P = 0.05) and 120 (R = 0.644; P = 0.009). In conclusion, repeated handling in the corral stresses cattle, but without compromising rabies humoral immune response.(AU)

Association between handling stress in the corral and rabies antibody titers in selenium-supplemented cattle

This study determined the correlation between serum cortisol levels and rabies antibody titers in cattle primo-vaccinated against rabies and supplemented with dietary selenium (Se). Sixty Nelore male calves (10 to 12 months old) received daily and individual dietary supplementation with 0, 3.6, 5.4 and 6.4 mg Se (groups Gc, G3.6, G5.4 and G6.4, respectively). The animals were vaccinated against rabies (day 0) and subjected to handling stress in the corral for 120 days. Blood sampling procedures were performed on days 0, 15, 30, 60, 90 and 120. Cortisol levels increased until day 90, but had dropped significantly by day 120 (P < 0.01). Rabies antibody titers on days 30 and 90 were similar among Se-supplemented groups; in the control group, rabies antibodies decreased significantly from day 30 to 60, and 90 to 120. Serum cortisol levels and antibody titers were not correlated in most of the groups or blood sampling days. A positive correlation among these variables was found only in G6.4 on days 60 (R = 0.513; P = 0.05) and 120 (R = 0.644; P = 0.009). In conclusion, repeated handling in the corral stresses cattle, but without compromising rabies humoral immune response.