Search

Enzymatically derived selenium-enriched peptides from Cardamine violifolia (CV) can serve as valuable selenium supplements. However, the industrial application of free enzyme is impeded by its limited stability and reusability. Herein, this study explores the application of co-immobilized enzymes (Alcalase and Dispase) on amino resin for hydrolyzing CV proteins to produce selenium-enriched peptides. The successful enzyme immobilization was confirmed through scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and Fourier-transform infrared spectroscopy (FTIR). Co-immobilized enzyme at a mass ratio of 5:1 (Alcalase/Dispase) exhibited the smallest pore size (7.065 nm) and highest activity (41 U/mg), resulting in a high degree of hydrolysis of CV protein (27.2%), which was obviously higher than the case of using free enzymes (20.7%) or immobilized Alcalase (25.8%). In addition, after a month of storage, the co-immobilized enzyme still retained a viability level of 41.93%, showing fairly good stability. Encouragingly, the selenium-enriched peptides from co-immobilized enzyme hydrolysis exhibited uniform distribution of selenium forms, complete amino acid fractions and homogeneous distribution of molecular weight, confirming the practicality of using co-immobilized enzymes for CV protein hydrolysis.

Donkey milk is a traditional medicinal food with various biological activities. However, its production is very low, and lactating donkeys often experience oxidative stress, leading to a further decline in milk yield. In this study, we supplemented the diets of lactating donkeys with yeast selenium (SY) to investigate its effects on lactation performance, antioxidant status, and immune responses, and we expected to determine the optimum additive level of SY in the diet. For this study, 28 healthy lactating Dezhou donkeys with days in milk (DIM, 39.93 ± 7.02 d), estimated milk yield (EMY, 3.60 ± 0.84 kg/d), and parity (2.82 ± 0.48) were selected and randomly divided into 4 groups of 7 donkeys in each: Group SY-0 (control), Group SY-0.15, Group SY-0.3, and Group SY-0.5, with selenium supplementation of 0, 0.15, 0.3, and 0.5 mg of Se/kg DM (in form of SY) to the basal diet, respectively. The results showed a dose-dependent increase in milk yield, milk component yield, milk protein production efficiency, milk production efficiency, the activities of glutathione peroxidases (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC), as well as the content of serum interleukin-10 (IL-10), white blood cells (WBC), lymphocytes (LYM), red blood cells (RBC), hematocrit, plasma selenium, and milk selenium. Conversely, it presented a dose-dependent decrease in the activity of nitric oxide synthase (iNOS) and the contents of malondialdehyde (MDA), reactive oxygen species (ROS), nitric oxide (NO), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interferon-γ (IFN-γ). In conclusion, the results confirmed that dietary supplementation with SY can improve lactation performance, antioxidant status, and immune responses in lactating donkeys, and the recommended dose of SY was 0.3 mg/kg.

Selenium polysaccharides have attracted significant interest due to their superior function to that of individual polysaccharides. However, limited research has compared the protective effects of different selenium polysaccharides from different selenization methods on diabetes. This work aims to compare the preventive effects of natural selenium-enriched green tea polysaccharides (NSe-TPS), synthetic selenized green tea polysaccharides (PCSe-TPS), and a mixture of sodium selenite and green tea polysaccharides (ordinary tea polysaccharides (Ord-TPS)+Se) on the development of diabetes. While establishing a diabetes model induced by a high-sugar, high-fat diet combined with streptozotocin, different selenium polysaccharides were administered daily by gavage for nine weeks. Our findings indicate that PCSe-TPS exhibited superior preventive effects on developing type 2 diabetes compared to NSe-TPS and Ord-TPS+Se. PCSe-TPS effectively regulated glucose metabolism and insulin resistance by activating the PI3K/Akt pathway, thereby preventing elevated blood glucose levels. Additionally, PCSe-TPS mitigated oxidative damage and inflammatory responses in liver tissues. Notably, PCSe-TPS intervention reversed the decline in bacterial species richness and the abundance of unclassified_Oscillospiraceae during the development of diabetes in mice. These results provide valuable insights into the protective effects of PCSe-TPS against diabetes development, highlighting its advantages over NSe-TPS and Ord-TPS+Se.

In this work, nanoparticles of Co 1-x Re x Fe 2 O 4 and CoFe 2-x Re x O 4 (0 ≤ x ≤ 0.05) were synthesized by the sol-gel method. The Rietveld refinement analysis of XRD and Raman data revealed that all of the prepared samples were single phase with a cubic spinel-type structure. With the substitution of Re, the lattice parameters were slightly increased, and Raman spectra peak positions corresponding to the movement of the tetrahedral sublattice shifted to a higher energy position. Furthermore, Raman spectra showed the splitting of T 2g mode into branches, indicating the presence of different cations at crystallographic A- and B-sites. The SEM micrograph confirms that surface Re exchange changes the coordination environment of metals and induces Fe-site structure distortion, thereby revealing more active sites for reactions and indicating the bulk sample's porous and agglomerated morphology. The vibrating sample magnetometer (VSM) results demonstrated that the synthesized nanoparticles of all samples were ferromagnetic across the entire temperature range of 300-4 K. The estimated magnetic parameters, such as the saturation magnetization, remanent magnetization, coercivity, blocking temperature ( T B ), and magnetic anisotropy, were found to reduce for the Co-site doping with the increasing doping ratio of Re, while in the Fe site, they enhanced with the increasing doping ratio. The ZFC-FC magnetization curve revealed the presence of spin-glass-like behavior due to the strong dipole-dipole interactions in these ferrite nanoparticles over the whole temperature range. Finally, the dielectric constant ( ε r ' ) and dielectric loss ( tan δ ) were sharply enhanced at low frequencies, while the AC conductivity increased at high frequencies. The sharp increases at high temperatures are explained by enhancing the barrier for charge mobility at grain boundaries, suggesting that samples were highly resistive. Interestingly, these parameters ( ε r ' , tan δ ) were found to be higher for the Fe-site doping with the increasing Re doping ratio compared with the Co site.