A Review of Plant Selenium-Enriched Proteins/Peptides: Extraction, Detection, Bioavailability, and Effects of Processing

Zein and gum arabic nanoparticles: potential enhancers of immunomodulatory functional activity of selenium-containing peptides

Food-derived nanomaterials optimizing bioactive peptides is an emerging route in the functional food field. Zein and gum arabic (GA) possess favorable encapsulation properties for controlled release, targeted delivery and stabilization of food bioactive ingredients, and thus are considered as promising carriers for delivery systems. In order to improve the bioavailability of rice selenium-containing peptide TSeMMM (T), the nanoparticles (ZTGNs) containing peptide T, zein and GA have been previously prepared. This study focused on evaluating the immunomodulatory capacity of ZTGNs. The results showed that ZTGNs significantly alleviated cyclophosphamide-induced reduction in immune organ indices and liver glutathione content of mice. There was a significant upregulation observed in the levels of immune-related cytokines IL-6, TNF-α, and IFN-γ as well as their mRNA expression. Moreover, ZTGNs enriched the diversity of the intestinal flora and promoted the proportion of beneficial bacteria. In conclusion, ZTGNs have potential as immunomodulatory enhancers for food bioactive ingredients, providing prospects for further optimization of dietary supplements.

Selenium Species in Diabetes Mellitus Type 2

Selenium is an important trace element for humans and animals as it plays a key role in several major metabolic pathways. Several studies were conducted to better understand the role of selenium against diabetes mellitus (DM), particularly type 2 (T2DM), but the obtained conclusions are contradictory. A simple linear relationship does not exist between the risk of T2DM and selenium levels but is best represented in a dose-dependent manner, getting often the U-graph. This relation also depends on selenium chemical forms that are present in a diet or supplements. Both too low and too high selenium intakes could increase the risk of diabetes. Moreover, the baseline status of Se should be taken into consideration to avoid over-supplementation. The focus of this brief overview is to report the recent updates concerning selenium participation in diabetes mellitus.

Mitigating cadmium exposure risk in rice with foliar nano-selenium: Investigations through Caco-2 human cell line in-vivo bioavailability assay

The contamination of paddy fields by cadmium and lead is a major issue in China. The consumption of rice grown in heavy metals contaminated areas poses severe health risks to humans, where bioavailability and bioaccessibility remains the critical factor for risk determination. Selenium nanoparticles (Se-NPs) can mitigate the toxicity of heavy metals in plants. However, there exists limited information regarding the role of Se-NPs in dictating cadmium (Cd) toxicity in rice for human consumption. Moreover, the impact of Se-NPs under simultaneous field and laboratory controlled conditions is rarely documented. To address this knowledge gap, a field experiment was conducted followed by laboratory scale bioavailability assays. Foliar application of Se-NPs and selenite (at 5, 10 mg L-1) was performed to assess their efficiency in lowering Cd accumulation, promoting Se biofortification in rice grains, and evaluating Cd exposure risk from contaminated rice. Obtained results indicate that foliar treatments significantly reduced the heavy metal accumulation in rice grains. Specifically, Se-NP 10 mg L-1 demonstrated higher efficiency, reducing Cd and Pb by 56 and 32 % respectively. However, inconsistent trends for bioavailable Cd (0.03 mg kg-1) and bioaccessible (0.04 mg kg-1) were observed while simulated human rice intake. Furthermore, the foliage application of Se-NPs and selenite improved rice quality by elevating Se, Zn, Fe, and protein levels, while lowering phytic acid content in rice grains. In summary, this study suggests the promising potential of foliage spraying of Se-NPs in lowering the health risks associated with consuming Cd-contaminated rice.

Egg Yolk Selenopeptides: Preparation, Characterization, and Immunomodulatory Activity

In this study, egg yolk selenium peptides (Se-EYP) were prepared using double-enzyme hydrolysis combined with a shearing pretreatment. The properties of the selenopeptides formed were then characterized, including their yield, composition, molecular weight distribution, antioxidant activity, in vitro digestion, and immunomodulatory activity. The peptide yield obtained after enzymatic hydrolysis using a combination of alkaline protease and neutral protease was 74.5%, of which 82.6% had a molecular weight <1000 Da. The selenium content of the lyophilized solid product was 4.01 μg/g. Chromatography-mass spectrometry analysis showed that 88.6% of selenium in Se-EYP was in the organic form, of which SeMet accounted for 60.3%, SeCys2 for 21.8%, and MeSeCys for 17.9%. After being exposed to in vitro simulated digestion, Se-EYP still had 65.1% of oligopeptides present, and the in vitro antioxidant activity was enhanced. Moreover, Se-EYP exhibited superior immune detection indices, including immune organ index, level of immune factors in the serum, histopathological changes in the spleen, and selenium content in the liver. Our results suggest that Se-EYP may be used as selenium-enriched ingredients in functional food products.

Iron hydroxyphosphate electro-Fenton catalyst for efficient removal of sulfamethoxazole and resource recycling into slow-release fertiliser ammonium ferrous phosphate

Although the electro-Fenton (EF) process is effective for wastewater treatment, recycling spent catalysts remain a major challenge. Therefore, we introduce a reuse strategy for spent catalysts where an iron hydroxyphosphate [Fe5(PO4)4(OH)3·2H2O] catalyst is utilized. Fe5(PO4)4(OH)3·2H2O obtained •OH and •O2- by activating in-situ produced H2O2, and the degradation rate of sulfamethoxazole reached 94.5% after 120 min and showed excellent stability (maintained above 90%) for 10 cycles. Finally, the used catalyst was converted into slow-release ammonium ferrous phosphate (NH4FePO4·H2O) fertiliser at a conversion rate of 85.6%. NH4FePO4·H2O significantly promoted plant and seed growth within 6 days, highlighting the contribution of the resource recycling of the spent catalyst. This study serves as a valuable reference for the efficient utilization of spent catalysts. This study successfully applied EF catalysts and explored the recycling of spent catalysts.

Selenium Modification of Natural Products and Its Research Progress

The selenization of natural products refers to the chemical modification method of artificially introducing selenium atoms into natural products to interact with the functional groups in the target molecule to form selenides. Nowadays, even though scientists in fields involving organic selenium compounds have achieved numerous results due to their continuous investment, few comprehensive and systematic summaries relating to their research results can be found. The present paper summarizes the selenization modification methods of several kinds of important natural products, such as polysaccharides, proteins/polypeptides, polyphenols, lipids, and cyclic compounds, as well as the basic principles or mechanisms of the selenizing methods. On this basis, this paper explored the future development trend of the research field relating to selenized natural products, and it is hoped to provide some suggestions for directional selenization modification and the application of natural active ingredients.