Nutritional Supplementation and Enhanced Antioxidant Function by Dietary Intake of Selenoneine and Other Selenium Compounds in Red Seabream Pagrus major.

Selenoneine, 2-selenyl-Nα, Nα, Nα-trimethyl-L-histidine, is the major organic selenium compound in marine fish. To characterize biological antioxidant function of selenoneine in fish, the accumulation of selenoneine and other selenium compounds, i. e., sodium selenite and selenomethionine, in the muscle and other tissues of red seabream. We reared red seabream by feeding of 1% dry pellet containing of sodium selenite, selenomethionine, or selenoneine of body weight twice a day for 4 weeks. After that, we replaced to 1% of normal commercial dry pellet of body weight twice a day for 1 week from the selenium supplementation, and tissue distribution of total selenium was determined. Selenium supplementation with selenoneine, selenomethionine, and sodium selenite enhanced selenium accumulation in the white muscle, kidney, and hepatopancreas in comparison with the control group. By the dietary intake of selenoneine, total selenium concentrations were increased in the white muscle, heart, kidney, spleen, hepatopancreas, brain, and blood cells in a dose-dependent manner during the trials after 2 weeks. Dietary intake of selenoneine as well as sodium selenite and selenomethionine reduced oxidation-reduction potential (ORP). Selenoneine concentrations in the white muscle and blood cells were accumulated for 4 weeks by the selenoneine intake, whereas selenoneine concentration was not elevated by the intake of selenomethionine and sodium selenite, suggesting that tissue selenoneine levels might be derived from only selenoneine-containing diet. The uptake factor of selenoneine from the artificial feed containing selenoneine was calculated to be 0.0062 in the white muscle and 4.0 in the blood. The half-life of total selenium in the blood cells and white muscle were estimated to be 60 days in the white muscle and 30 days in the blood.

Dietary Intake of Selenoneine Enhances Antioxidant Activity in the Muscles of the Amberjack Seriola dumerili Grown in Aquaculture.

The selenium (Se)-containing imidazole compound selenoneine (2-selenyl-Nα, Nα, Nα-trimethyl-L-histidine) is a strong scavenger of reactive oxygen species (ROS) in the blood and tissues of fish. Intravenous injection of selenoneine into yellowtail has been shown to delay changes in meat color and prevent met-myoglobin formation in red muscle. In this study, to determine whether selenoneine can improve stress tolerance and meat quality in fish, we examined the biological antioxidant functions of selenoneine in fish in vivo. Juvenile amberjack (Seriola dumerili) were cultured and fed a diet containing selenoneine for 9 weeks. Total Se and selenoneine concentrations increased in amberjack blood and muscles during the study period. We also measured the oxidative-redox potential (ORP) in fish muscle using an ORP electrode and found that muscle ORP and ROS levels were closely correlated with the Se concentration in blood and muscles. We conclude that dietary administration of selenoneine led to its accumulation in amberjack blood and muscles, resulting in reduced ORP and ROS levels in the muscles.