Selenium Nanoparticles Ameliorate Adverse Impacts of Aflatoxin in Nile Tilapia with Special Reference to Streptococcus agalactiae Infection.

Aflatoxin B1 (AFB1) is a plant-origin toxin that could induce oxidative stress in fish. The micromineral selenium (Se) possesses well-documented antioxidant properties. To assess the ameliorative effects of SeNPs (1 mg/kg fish feed) on oxidative stress induced by AFB1 (500 µg/kg fish feed), Nile tilapia (32.2±1.7 g body weight) were distributed randomly and even in six groups for 8-week feeding trial. Live enzymes, AST, ALT, and ALP levels were increased in the serum of fish fed AFB1-contaminated diet, and the addition of SeNPs could restore normal values compared to the control. The gene expression of antioxidant enzymes, superoxide dismutase (SOD) enzyme and catalase (CAT) enzyme, and DNA fragmentation were significantly increased in response to aflatoxin exposure, while dietary SeNPs could mitigate the generated oxidative stress. The innate immunity, serum antibacterial activity (SAA), oxidative burst activity (OBA), phagocytic activities (PA and PI), and gene expression of cytokines (interleukin (IL)-1ß, heat shock protein70 (Hsp), and tumor necrosis factor (TNF)-α) revealed a status of immunosuppression in Nile tilapia fed on AFB1-contaminated diet. These findings showed that fish became more vulnerable to Streptococcus agalactiae infection with a high mortality rate while dietary SeNPs provided a high relative protection level (RPL). From the obtained findings, SeNPs could mitigate the oxidative stress induced by feeding the AFB1 diet and could boost the immunity of stressed Nile tilapia.

Response of rumen fermentation and microbiota to dietary supplementation of sodium selenite and bio-nanostructured selenium in lactating Barki sheep.

Dietary selenium (Se) sources affects the structure of the rumen microbial community and rumen fermentation. This study evaluated the effects of sodium selenite (SS) and bio-nanostructured selenium (SeNSM) on rumen fermentation and structure of rumen microbial community of lactating Barki ewes. Twenty one lactating Barki ewes were assigned into three groups based on their body weight and milk yield. The experiment lasted for 50 days, whenever, the control group was fed basal diet; group SS received basal diets plus sodium selenite as inorganic source of Se; and group SeNSM received basal diet plus organic selenium bio-nanostructured. Ruminal pH and volatile Fatty Acids (VFA) was lower (P < 0.05) in SeNSM group compared to control. Principle Coordinate Analysis separated the microbial communities into three clusters based on feeding treatment. The bacterial community was dominated by phylum Bacteroidetes and Firmicutes that were affected (P < 0.05) by Se sources. Specifically Bacteriodetes was higher (P < 0.05) in SS and SeNSM groups; and Firmicutes was higher (P < 0.05) in the control group. Moreover, the predominant bacterial genera were Prevotella, Rikenellaceae RC9 gut group, Unclassified_Bacteroidales, which were higher (P < 0.05) in SeNSM group. The methanogenic community belonged to phylum Euryarchaeota and was significantly decreased (P < 0.05) by Se supplementation. Principal component analysis based on rumen fermentation parameters, and relative abundances of bacteria and methanogens revealed three distinct clusters. These findings suggest that Se supplementation affected the relative abundances of dominant bacterial groups, declined rumen methanogens and SeNSM supplementation showed some positive impacts on some fibrolytic bacteria.

Supplementing bovine milk immunoglobulin G prevents rats fed on a vitamin E-deficient diet from developing peroxidation stress.

BACKGROUND/AIMS: Bovine milk whey, which mainly includes beta-lactoglobulin (58%), alpha-lactalbumin (22%) and immunoglobulin G (IgG; 11%), is a source of a wide range of proteins with a useful nutritional and physiological function. We previously demonstrated antiperoxidative effects of whey-derived alpha-lactalbumin and beta-lactoglobulin in rats. The aim of the present study was to investigate the role of the IgG in antiperoxidative properties. METHODS: Four-week-old, male Sprague-Dawley rats were fed a vitamin E-deficient diet (control) or a diet supplemented with 2.5% of an IgG-rich fraction for 4 weeks. Different antiperoxidative parameters were measured in blood and liver from the rats. RESULTS: In comparison to the rats fed the control diet, those fed the IgG-containing diet were resistant to peroxidation stress. The IgG diet resulted in a decreased concentration of thiobarbituric acid-reactive substances in red blood cells (RBC) and plasma, and increased activities of catalase, superoxide dismutase and glutathione peroxidase in the RBC and liver. The plasma density (d) < 1.063 g/ml lipoproteins from the IgG group were more resistant against the induced lipid peroxidation. CONCLUSION: These results demonstrate antiperoxidative properties of IgG. The underlying mechanism(s) remain to be determined.