Cellular Antioxidant Research Articles

Turn Hood into Good: Recycling Silicon from Mesoporous Silica Nanoparticles through Magnesium Modification to Lower Toxicity and Promote Tissue Regeneration.

Mesoporous silica nanoparticles (MSNs) have gained wide application as excellent carrier materials; however, their limited degradation in the biological system and potential chronic toxicity pose challenges to their clinical applications. Previous studies have focused on optimizing the elimination performance of MSNs; interestingly, silicon has been well-documented as an essential body component. Therefore, converting MSNs into a form readily utilizable by the organism is a way to turn waste into a valuable resource. However, the recycling and utilization of MSNs are associated with significant hurdles. This study proposes an approach to impede the formation of siloxane, the crucial core in MSNs, by introducing a gradient concentration of Mg2+. The invasion of Mg2+ significantly reduces the stability of Si-O-Si bonds by substituting silicon ions while preserving the functional three-dimensional structure. Recycling the increased release of Mg and Si ions enhances cellular antioxidant capacity, reduces oxidative stress reactions, improves mitochondrial function, and regulates macrophage inflammatory states. The proposed approach to converting MSN materials shows significant advantages for tissue regeneration in the periodontal defect model. This study opens an insight for applying MSNs in clinical applications in regenerative medicine.

An Immunoregulatory and Metabolism-Improving Injectable Hydrogel for Cardiac Repair After Myocardial Infarction

Abstract The hypoxia microenvironment post myocardial infarction (MI) critically disturbs cellular metabolism and inflammation response, leading to scarce bioenergy supplying, prolonged inflammatory phase and high risk of cardiac fibrosis during cardiac restoration. Herein, an injectable hydrogel is prepared by Schiff-base reaction between fructose-1,6-bisphosphate (FBP)-grafted carboxymethyl chitosan (CF) and oxidized dextran (OD), following by loading fucoidan-coated baicalin (BA)-encapsulated zein nanoparticles (BFZ NPs), in which immunoregulatory and metabolism improving functions are integrally included. The grafted FBP serves to enhance glycolysis and provide more bioenergy for cardiomyocytes survival under hypoxia microenvironment, and elevating cellular antioxidant capacity via pentose phosphate pathway. OD with intrinsic anti-inflammatory effect can induce M2 polarization of macrophages to accelerate inflammatory elimination. While facing the possibility of endothelial-to-mesenchymal transition (EndoMT) caused by excessive expressed TGF-β1 secreted from M2 macrophages, BFZ NPs can target endothelia cells and intracellularly release BA to regulate the level of fatty acid oxidation, resulting in retained endothelial features and decreased risk of cardiac fibrosis. After being injecting the hydrogel into rats’ infarcted cardiac, the 28 day-post surgical outcomes demonstrate its benign effects on restoring cardiac functions and attenuating adverse left ventricular remodeling. This study shows a promising measure for MI treatment with immunoregulating and metabolism regulation comprehensively.

Moringa oleifera Lam. Leaf Peptides: Antioxidant and Antiproliferative Activity in Human Colon Cancer Caco-2 Cell Line

Reactive oxygen species are produced as part of the cellular metabolism. However, lifestyle can promote an excess in their concentration. Free radicals react with DNA, promoting the appearance of cancer cells. Therefore, natural antioxidants have been suggested as an alternative to prevent this disorder. Peptides are protein fragments that have been produced from various plants. In previous work, Moringa oleifera leaf peptides (MOPHs) with antioxidant potential were generated and identified. However, the spectrophotometric methods used to evaluate their antioxidant activity do not fully reflect its potential. In this work, the antioxidant activity of MOPHs was assessed by the ferric reducing antioxidant power assay (FRAP) and cellular antioxidant activity method on the human colon cancer cell line Caco-2. Also, their antiproliferative activity was evaluated. The MOPHs exhibited a FRAP activity of 1435 µmol TE/g, and at 500 µg/mL; the peptides did not show a cytotoxic effect on healthy colon CCD-18Co cells. Moreover, the MOPHs increased Caco-2 antioxidative activity to a greater extent by 73.45% and 83.62% at 250 and 500 µg/mL, respectively. Regarding cellular proliferation, the MOPHs inhibited it by 78.19% and 90.20% at 200 and 500 µg/mL, respectively. These findings highlight the potential of Moringa oleifera leaf peptides as functional ingredients with significant health benefits, demonstrating antioxidant and antiproliferative properties.

Menstrual Blood-Derived Endometrial Stem Cells Ameliorate Ovarian Senescence by Relieving Oxidative Stress-Induced Inflammation.

Senescence is a degenerative process that occurs with ageing, and in the female reproductive system, senescence occurs earlier in the ovaries than in other tissues and organs, which implies a decrease in oocyte quality and exhaustion of the primordial follicular pool, leading to impaired ovarian function and an inability to maintain normal fertility. Unfortunately, the development of curative and effective treatments for ovarian senescence is still a considerable challenge. Currently, mesenchymal stem cells (MSCs)-based therapies for treating various refractory diseases, especially ovarian dysfunction, have been extensively studied and confirmed. However, the mechanisms by which MSCs improve ovarian senescence are not yet clear. Therefore, in this study, a mouse ageing model was generated via the intraperitoneal injection of a D-galactose (D-gal) solution, and the effects of menstrual blood-derived endometrial stem cells (MenSCs) transplantation on the ovarian follicle count, fibrosis level, and degree of apoptosis were evaluated. Subsequently, an ovarian granulosa cell ageing model was induced with H2O2, and CCK-8 assays, flow cytometry, mitochondrial membrane potential analysis and Western blotting were subsequently performed to further investigate the potential mechanism by which MenSCs ameliorate cellular oxidative damage. Overall, our findings demonstrated that MenSCs treatment can increase the cellular antioxidant capacity by activating the NRF2/HO-1 signalling pathway and further ameliorate the inflammatory ovarian microenvironment, apoptosis and dysfunction in ageing mice. These results provide reliable evidence and support for MenSCs-based therapy for ovarian senescence.

Oxidants-induced high levels of nitric oxide impair the antioxidative property of molybdenum nanoparticles in HUVE cells

In recent years, there has been significant interest in the biomedical potential of redox-active molybdenum nanoparticles (Mo NPs) due to their varied responses from oxidative to antioxidative. Our knowledge of the bio-response of Mo NPs in endothelial cells is lacking. We, therefore, are prompted to examine the biocompatibility of well-characterized Mo NPs in human endothelial (HUVE) cells and their potential antioxidative response against standard oxidants- tert-butyl hydroperoxide (t-BHP) and hydrogen peroxide (H2O2). The study found that Mo NPs were highly biocompatible in HUVE cells and enhanced cellular antioxidant glutathione (GSH), significantly protecting cells against exogenous oxidants. Moreover, Mo NPs significantly restored the loss of mitochondrial membrane potential (MMP) determined by the Rh123 probe. They decreased reactive oxygen species (ROS) levels as measured by DHE and DCFH-DA probes. In light of Mo involvement in the nitric oxide (NO) metabolism and dependency of HUVE cells on NO signaling, intracellular NO was determined using DAR-2 fluorescent dye and the Griess assay. NO was not produced significantly by Mo NPs alone or t-BHP or H2O2. However, NO generation was significantly high when HUVE cells were co-exposed with Mo NPs and exogenous oxidants. Although the exact mechanism is unclear to us, our study concludes that the enhanced generation of NO under the co-exposure of oxidants with Mo NPs can impair the potential antioxidative property of Mo NPs, especially in endothelial cells. The study also suggests that NO modulatory strategies can improve and broaden the antioxidative properties of Mo-based nanoparticles.

Oxygen-generating hydrogels combined with electrical stimulation: A dual approach for promoting diabetic wound healing

Chronic wounds resulting from hyperglycemia and hypoxia are common complications in diabetic patients, posing significant challenges for clinical treatment. In this study, we developed a hydrogel (PVNP-SP) using [VBIM]Br, NIPAM, PEGDA, and spirulina, which exhibited strong antioxidant properties. The incorporation of [VBIM]Br endowed the hydrogel with electrical conductivity, allowing it to activate voltage-gated ion channels under an external electric field, thereby promoting cell survival and migration. The hydrogel also enhanced cellular antioxidant capacity by providing sustained oxygenation, inhibiting HIF-1α nuclear translocation, and activating the Nrf2/HO-1 pathway. Notably, in a chronic wound model, the combined effects of oxygen production and electrical stimulation from the PVNP-SP hydrogel significantly reduced wound inflammation, promoted collagen deposition and angiogenesis, and facilitated early wound closure. This therapeutic strategy, which mitigates hypoxia while integrating electrical stimulation, offers a highly effective strategy for improving chronic wound healing in diabetic patients. Statement of significanceInspired by photoautotrophic organisms, we combined microalgae with a conductive hydrogel and we demonstrated the synergistic promotion of chronic wound healing by electrical stimulation combined with microalgae oxygen-producing hydrogel. The approach of combining microalgae hydrogel patches with electrical stimulation demonstrates the feasibility of delivering oxygen to tissues while combining electrical stimulation for synergistic tissue repair. The hydrogel is easy to fabricate and handle, and may be suitable for a variety of treatments, such as myocardial infarction, lower limb ischemia, and drug delivery. The potential applicability of this hydrogel in a variety of treatments suggests that it has promising applications in regenerative medicine.

Isolation, Purification, and Antioxidant Activity of Polyphenols from Cynanchum auriculatum Royle ex Wight

Cynanchum auriculatum Royle ex Wight (CA) is a traditional medicinal and edible plant in China. This study aimed to isolate and characterize the phenolic compounds of C. auriculatum to identify its main antioxidant constituents. Polyphenols were extracted using an ultrasound-assisted ethanol extraction method, followed by partitioning with ethyl acetate. The ethyl acetate extract was then purified through thin-layer chromatography, silica gel column chromatography, and reverse-phase silica gel column chromatography. Three monomeric compounds—cynandione A (I), 2,5-dihydroxyacetophenone (II), and radix piperacanthone (III)—were identified through their physical and chemical properties, UV and IR spectra, and liquid chromatography–mass spectrometry (LC-MS/MS). Vitamin C (VC) and 2,4-dihydroxyacetophenone were used as controls to evaluate the antioxidant potential of the two most abundant monomers. Antioxidant assays demonstrated that 2,5-dihydroxyacetophenone and cynandione A exhibited strong antioxidant activity at lower concentrations, whereas 2,4-dihydroxyacetophenone showed significantly weaker activity. Furthermore, cynandione A displayed superior cellular antioxidant activity compared to 2,5-dihydroxyacetophenone, indicating its potential as a promising bioactive compound. In conclusion, this study provides valuable insights into the phenolic composition of C. auriculatum and highlights cynandione A as a key antioxidant, paving the way for future research on its therapeutic applications.

Nanochitosan-encapsulated melatonin: an eco-friendly strategy to delay petal senescence in cut gerbera flowers

BackgroundThe preservation of cut flowers, particularly Gerbera jamesonii, is crucial for maintaining their aesthetic value and extending vase life in the floriculture industry. To address this challenge, this study investigated the effects of melatonin (Mel) and encapsulated melatonin with nanochitosan (nCS-Mel) as preservative solutions on cut Gerbera jamesonii cv. ‘Terra kalina’ flowers. In research, we examined various physiological and biochemical parameters, including relative water content, membrane stability index, carbohydrate content, and antioxidant enzyme activities, to evaluate the efficacy of these treatments in prolonging the vase life and quality of cut gerbera flowers under controlled environmental conditions.ResultsOur results demonstrated that cut Gerbera jamesonii flowers maintained in vase solutions containing 0.1 and 0.5 mM nCS-Mel exhibited enhanced preservation of cell membrane integrity and anthocyanin content, while also maintaining higher levels of carbohydrates and total flavonoids in petals at the conclusion of their vase life. A decline in petal relative water content and protein levels was observed concomitantly with petal senescence, whereas total phenolic compounds showed an increase. The hydrogen peroxide (H2O2) content in petals exhibited an upward trend during vase life in control specimens, but this effect was mitigated in treatments containing melatonin. Although malondialdehyde (MDA) content generally increased throughout the vase life period, flowers subjected to either Mel or nCS-Mel treatments displayed reduced MDA accumulation. The activity of catalase (CAT) demonstrated an increasing trend during vase life, with the maximum activity observed in Gerbera flowers treated with 0.1 mM nCS-Mel. A similar upward trend was noted for superoxide dismutase (SOD) activity, with flowers in 0.5 mM nCS-Mel treatment exhibiting peak SOD values on day 12 relative to control and other treatments. Peroxidase (POD) activity also increased across all treatments, with particularly pronounced effects in vase solutions containing 0.1 mM Mel and nCS-Mel. Notably, flowers placed in vase solutions containing 0.1 mM nCS-Mel, followed by 0.5 mM nCS-Mel and 0.1 mM Mel, exhibited the most prolonged vase life, extending up to 12, 10.66, and 10.33 days, respectively, under room temperature conditions.ConclusionsThe application of nanoencapsulated melatonin as a vase solution for cut Gerbera jamesonii flowers demonstrates significant potential in extending vase life and maintaining flower quality through enhanced preservation of cellular integrity, antioxidant activity, and biochemical parameters. This innovative approach not only outperforms conventional treatments but also presents a more environmentally friendly alternative to traditional antimicrobial preservatives and sugars, offering a promising solution for the floriculture industry to improve cut flower longevity and reduce ecological impact.

Role of sumoylation modification of sirtuin 3 in hypertension-associated

Abstract Objective The present study was designed to investigate whether mitochondrial dysfunction and oxidative stress in HTN-injured cardiomyocytes are associated with SIRT3 SUMOylation and whether SIRT3 deSUMOylation can ameliorate the related cardiomyocyte injury. Design and method The human cardiomyocyte AC16 cell line was used for the study. The SIRT3-K288R cell line was constructed by lentiviral transfection;The expression of SOD2, acetyl-SOD2 (MnSOD), protein acetylation level, inflammatory vesicle NLRP3, etc. in different subgroups were detected by Western Blot, and the roles of SUMOylation modification and SIRT3 deacetylation in HTN-associated cell injury were investigated by flow cytometry. Results (1) Western Blot results showed that compared to the HTN cell injury model, the cardiomyocytes in the SIRT3-K288R intervention group had increased Acetyl- SOD2/SOD2 levels were increased (p < 0.05) and protein acetylation levels were decreased in the SIRT3-K288R intervention group compared with the HTN cell injury model, indicating that SIRT3 increased the deacetylation effect on mitochondria and increased cellular antioxidant stress enzyme activity; (2) Western Blot results showed that compared with the HTN cell injury model, cardiomyocytes in the SIRT3-K288R intervention group NLRP3 and NOX4 levels were significantly reduced, indicating that SIRT3 deSUMOylation could improve the inflammatory response to Ang-II-related cell injury. (3) Flow cytometry results showed that K288R transfection ameliorated the reduction of cellular membrane potential, suggesting that deSUMOylation modification of SIRT3 reduces Ang-II damage to mitochondrial membrane potential. Conclusions In the HTN-associated cell injury model, the removal of SUMOylation modification by viral transfection could improve oxidative stress, protein acetylation levels and associated inflammatory responses in HTN-injured cardiomyocytes, indicating that SIRT3 SUMOylation may play an important mechanism in HTN-associated cell injury, and reducing SIRT3 SUMOylation modification may be a possible direction for future research.

Overview and trends in electrochemical sensors, biosensors and cellular antioxidant assays for oxidant and antioxidant determination in food

Screening and quantifying antioxidants from food samples, their antioxidant activity, as well as the assessment of food oxidation is critical, not only for ensuring food quality and safety, but also to understand and relate these parameters to the shelf life, sensory attributes, and health aspects of food products. For this purpose, several methods have been developed and used for decades, which regardless of their effectiveness, present a certain number of drawbacks mainly related to extensive sample preparation and technical complexity, time requirements, and the use of hazardous chemicals. Electrochemical sensors and biosensors are gaining popularity in food analysis due to their high sensitivity, specificity, rapid response times, and potential for miniaturisation and portability. Furthermore, other modern methods using whole living cells such as the cellular antioxidant activity assay, the antioxidant power 1 assay, and the catalase-like assays, may interpret more realistic antioxidant results rather than just reporting the ability to scavenge free radicals in isolated systems with extrapolation to reality. This paper provides an overview of electrochemical sensors, biosensors, and cellular antioxidant assays, and reviews the latest advancements and emerging trends in these techniques for determining oxidants and antioxidants in complex food matrices. The performances of different strategies are described for each of these approaches to provide insights into the extent to which these methods can be exploited in the field and inspire new research to fill the current gaps.

Selenocysteine tRNA methylation promotes oxidative stress resistance in melanoma metastasis.

Selenocysteine-containing proteins play a central role in redox homeostasis. Their translation is a highly regulated process and is dependent on two tRNASec isodecoders differing by a single 2'-O-ribose methylation called Um34. Here we characterized FTSJ1 as the Um34 methyltransferase and show that its activity is required for efficient selenocysteine insertion at the UGA stop codon during translation. Specifically, loss of Um34 leads to ribosomal stalling and decreased UGA recoding. FTSJ1-deficient cells are more sensitive to oxidative stress and show decreased metastatic colonization in xenograft models of melanoma metastasis. We found that FTSJ1 mediates efficient translation of selenoproteins essential for the cellular antioxidant response. Our findings uncover a role for tRNASec Um34 modification in oxidative stress resistance and highlight FTSJ1 as a potential therapeutic target specific for metastatic disease.

Lactobacillus reuteri or Lactobacillus rhamnosus GG intervention facilitates gut barrier function, decreases corticosterone and ameliorates social behavior in LPS-exposed offspring

Probiotic therapy with Lactobacillus reuteri and Lactobacillus rhamnosus (LGG) demonstrates potential as an adjunctive treatment for autism spectrum disorder (ASD). In a rat model of ASD induced by lipopolysaccharide (LPS) injection during pregnancy, we evaluated the effects of these probiotics on offspring. Administration of L. reuteri or LGG for three weeks post-birth improved social deficits and reduced anxiety in LPS-exposed rats. Additionally, probiotics significantly modified short-chain fatty acid profiles, increasing butyric acid levels and decreasing propionic acid levels. They also enhanced colonic barrier integrity by upregulating tight junction proteins, including ZO-1, Occludin, and Claudin4. RNA sequencing identified differential gene expression in pathways related to inflammation, the HPA axis, and reactive oxygen species metabolism, with NADPH oxidase 1 (NOX1) emerging as a crucial gene. Validation studies confirmed that Lactobacillus strains reduced inflammatory cytokines, inhibited corticosterone secretion, increased antioxidant levels, and suppressed the NF-κB/NOX1 pathway. In an H2O2-induced oxidative stress model using Caco-2 cells, pre-treatment with L. reuteri, LGG, or NF-κB inhibitors enhanced cellular antioxidants, inhibited NF-κB/NOX1 activation, and improved barrier function. Overall, L. reuteri and LGG administration improved social behavior, bolstered colonic barrier function, and mitigated HPA axis overactivation in LPS-exposed rats, while also alleviating oxidative stress in the colon and Caco-2 cells. These findings suggest that L. reuteri and LGG have substantial clinical potential for ASD treatment by targeting multiple pathophysiological mechanisms, including inflammation, HPA axis dysregulation, and oxidative stress, thereby presenting a promising adjunctive therapeutic strategy for enhancing social behavior and gut health in ASD.

Metabolic pathways regulated by strigolactones foliar spraying enhance osmoregulation and antioxidant defense in drought-prone soybean

BackgroundDrought stress is a significant abiotic stressor that hinders growth, development, and crop yield in soybeans. Strigolactones (SLs) positively regulate plant resistance to drought stress. However, the impact of foliar application of SLs having different concentrations on soybean growth and metabolic pathways related to osmoregulation remains unknown. Therefore, to clarify the impact of SLs on soybean root growth and cellular osmoregulation under drought stress, we initially identified optimal concentrations and assessed key leaf and root indices. Furthermore, we conducted transcriptomic and metabolic analyses to identify differential metabolites and up-regulated genes.ResultsThe results demonstrated that drought stress had a significant impact on soybean biomass, root length, root surface area, water content and photosynthetic parameters. However, when SLs were applied through foliar application at appropriate concentrations, the accumulation of ABA and soluble protein increased, which enhanced drought tolerance of soybean seedlings by regulating osmotic balance, protecting membrane integrity, photosynthesis and activating ROS scavenging system. This also led to an increase in soybean root length, lateral root number and root surface area. Furthermore, the effects of different concentrations of SLs on soybean leaves and roots were found to be time-sensitive. However, the application of 0.5 µM SLs had the greatest beneficial impact on soybean growth and root morphogenesis under drought stress. A total of 368 differential metabolites were screened in drought and drought plus SLs treatments. The up-regulated genes were mainly involved in nitrogen compound utilization, and the down-regulated metabolic pathways were mainly involved in maintaining cellular osmoregulation and antioxidant defenses.ConclusionsSLs enhance osmoregulation in soybean plants under drought stress by regulating key metabolic pathways including Arachidonic acid metabolism, Glycerophospholipid metabolism, Linoleic acid metabolism, and Flavone and flavonol biosynthesis. This study contributes to the theoretical understanding of improving soybean adaptability and survival in response to drought stress.

Lactic acid bacteria supplementation: A bioprotective approach to mitigating cadmium-induced toxicity and modulating gene expression in murine models

This study aimed to assess the effects of different strains of lactic acid bacteria, namely LeviLactobacillus brevis (AC10), Lacticaseibacillus rhamnosus (AC11), and Pediococcus acidilactici (AC15), on mice exposed to cadmium-induced oxidative stress. The study assessed weight gain, liver enzymes, antioxidant enzymes, immunoglobulin factors, lipid peroxidation, and gene expression in liver and brain of mice. The findings revealed that the AC10 and AC11 strains had a higher ability to absorb Cd as compared to AC15. The in vivo analysis demonstrated that the dietary dual supplementation of AC10 and AC11 resulted in significant (p < 0.05) improvements, including increased body weight and food intake, reduced cadmium tissue deposition, decreased lipid peroxidation, enhanced cellular antioxidant redox potential, suppressed inflammation genes in the liver and brain tissues, and improved morpho-characteristics of the jejunum in mice challenged by cadmium-induced toxicity. The multiple mechanisms of action, including heavy metal sequestration, antioxidant enhancement, and maintenance of intestinal integrity, highlight the potential of these probiotics’ intervention as a viable approach to counteract the deleterious effects of cadmium exposure.

Arsenic and Chromium Induced Toxicity on Zebrafish Kidney: Mixture Effects on Oxidative Stress and Involvement of Nrf2-Keap1-ARE, DNA Repair, and Intrinsic Apoptotic Pathways.

In polluted water, cooccurrences of two carcinogens, arsenic (As) and chromium (Cr), are extensively reported. Individual effects of these heavy metals have been reported in kidney of fishes, but underlying molecular mechanisms are not well established. There is no report on combined exposure of As and Cr in kidney. Thus, the present study investigated and compared individual and combined effects of As and Cr on zebrafish (Danio rerio) kidney treating at their environmentally relevant concentrations for 15, 30, and 60 days. Increased ROS levels, lipid peroxidation, GSH level, and decreased catalase activity implied oxidative stress in treated zebrafish kidney. Damage in histoarchitecture in treated groups was also noticed. The current study involved gene expression study of Nrf2, an important transcription factor of cellular stress responses along with its negative regulator Keap1 and downstream antioxidant genes nqo1 and ho1. Results indicated activation of Nrf2-Keap1 pathway after combined exposure. Expression pattern of ogg1, apex1, polb, and creb1 revealed the inhibition of base excision repair pathway in treatments. mRNA expression of tumor suppressor genes p53 and brca2 was also altered. Expressional alteration in bax, bcl2, caspase9, and caspase 3 indicated apoptosis (intrinsic pathway) induction, which was maximum in combined group. Inhibition of DNA repair and induction of apoptosis indicated that the activated antioxidant system was not enough to overcome the damage caused by As and Cr. Overall, this study revealed additive effects of As and Cr in zebrafish kidney after chronic exposure focusing cellular antioxidant and DNA damage responses.

Antioxidant Properties of Postbiotics: An Overview on the Analysis and Evaluation Methods.

Antioxidants found naturally in foods have a significant effect on preventing several human diseases. However, the use of synthetic antioxidants in studies has raised concerns about their potential link to liver disease and cancer. The findings show that postbiotics have the potential to act as a suitable alternative to chemical antioxidants in the food and pharmaceutical sectors. Postbiotics are bioactive compounds generated by probiotic bacteria as they ferment prebiotic fibers in the gut. These compounds can also be produced from a variety of substrates, including non-prebiotic carbohydrates such as starches and sugars, as well as proteins and organic acids, all of which probiotics utilize during the fermentation process. These are known for their antioxidant, antibacterial, anti-inflammatory, and anti-cancer properties that help improve human health. Various methodologies have been suggested to assess the antioxidant characteristics of postbiotics. While there are several techniques to evaluate the antioxidant properties of foods and their bioactive compounds, the absence of a convenient and uncomplicated method is remarkable. However, cell-based assays have become increasingly important as an intermediate method that bridges the gap between chemical experiments and in vivo research due to the limitations of in vitro and in vivo assays. This review highlights the necessity of transitioning towards more biologically relevant cell-based assays to effectively evaluate the antioxidant activity of postbiotics. These experiments are crucial for assessing the biological efficacy of dietary antioxidants. This review focuses on the latest applications of the Caco-2 cell line in the assessment of cellular antioxidant activity (CAA) and bioavailability. Understanding the impact of processing processes on the biological properties of postbiotic antioxidants can facilitate the development of new food and pharmaceutical products.

The Effect of Multilayer Nanoemulsion on the In Vitro Digestion and Antioxidant Activity of β-Carotene.

The objectives of this study were to design multilayer oil-in-water nanoemulsions using a layer-by-layer technique to enhance the stability of β-carotene and evaluate its effect on in vitro release and antioxidant activity. To prepare β-carotene-loaded multilayer nanoemulsions (NEs), a primary NE (PRI-NE) using Tween 20 was coated with chitosan (CS) for the secondary NE (SEC-CS), and with dextran sulfate (DS) and sodium alginate (SA) for the two types of tertiary NEs (TER-DS, TER-SA). The multilayer NEs ranged in particle size from 92 to 110 nm and exhibited high entrapment efficiency (92-99%). After incubation in a simulated gastrointestinal tract model, the release rate of free fatty acids decreased slightly after coating with CS, DS, and SA. The bioaccessibility of β-carotene was 7.02% for the PRI-NE, 7.96% for the SEC-CS, 10.88% for the TER-DS, and 10.25% for the TER-SA. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging abilities increased by 1.2 times for the multilayer NEs compared to the PRI-NE. In addition, the cellular antioxidant abilities improved by 1.8 times for the TER-DS (87.24%) compared to the PRI-NE (48.36%). Therefore, multilayer nanoemulsions are potentially valuable techniques to improve the stability, in vitro digestion, and antioxidant activity of β-carotene.

Proteomics Analysis on the Effects of Oxidative Stress and Antioxidants on Proteins Involved in Sterol Transport and Metabolism in Human Telomerase Transcriptase-Overexpressing-Retinal Pigment Epithelium Cells.

Age-related macular degeneration (AMD) is the most prevalent ocular disease in the elderly, resulting in blindness. Oxidative stress plays a role in retinal pigment epithelium (RPE) pathology observed in AMD. Tocopherols are potent antioxidants that prevent cellular oxidative damage and have been shown to upregulate the expression of cellular antioxidant proteins. Here, we determined whether oxidative stress and tocopherols, using either normal cellular conditions or conditions of sublethal cellular oxidative stress, alter the expression of proteins mediating sterol uptake, transport, and metabolism. Human telomerase transcriptase-overexpressing RPE cells (hTERT-RPE) were used to identify differential expression of proteins resulting from treatments. We utilized a proteomics strategy to identify protein expression changes in treated cells. After the identification and organization of data, we divided the identified proteins into groups related to biological function: cellular sterol uptake, sterol transport and sterol metabolism. Exposure of cells to conditions of oxidative stress and exposure to tocopherols led to similar protein expression changes within these three groups, suggesting that α-tocopherol (αT) and γ-tocopherol (γT) can regulate the expression of sterol uptake, transport and metabolic proteins in RPE cells. These data suggest that proteins involved in sterol transport and metabolism may be important for RPE adaptation to oxidative stress, and these proteins represent potential therapeutic targets.

Microalgal astaxanthin ameliorates cypermethrin-induced necroptosis and inflammation via targeting mitochondrial Ca2+ homeostasis and the ROS-NF-κB-RIPK3/MLKL axis in carp hepatocytes (Cyprinus carpio)

Cypermethrin is a toxic pesticide that has infiltrated water bodies due to its widespread use. This contamination has led to detrimental effects on the immune organs of aquatic species, including fish. The natural fat-soluble orange-red carotenoid, astaxanthin (MAT), derived from microalgae, possesses anti-inflammatory, antioxidant, and immunomodulatory properties. To elucidate the mechanism of CY induced damage to carp liver cells and assess the potential protective effects of MAT, we established a carp hepatocyte model exposed to CY and/or MAT. Hepatocytes from carp (Cyprinus carpio) were treated with either 8 μM CY or 60 μM MAT for 24 h. Upon exposure CY, a significant increase in reactive oxygen species (ROS) was observed alongside a diminution in the activities of key antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), suggesting an impairment of cellular antioxidant capacity. Subsequently, acridine orange/ethidium bromide (AO/EB) staining and flow cytometry analysis revealed that hepatocytes exposed to CY exhibited a higher incidence of necroptosis, associated with an elevated mitochondrial Ca2+ concentration, which contributed to cellular dysfunction. Furthermore, exposure to CY also activated the ROS-NF-κB-RIPK3/MLKL signaling pathway, increasing the levels of necroptosis-related regulatory factors (RIP1, RIP3, and MLKL) in hepatocytes and the expression of inflammatory genes (IL-6, IFN-γ, IL-4, IL-1β, and TNF-α), which led to immune dysfunction in hepatocytes. The immunotoxic effects induced by CY were mitigated by MAT treatment, suggesting its potential in alleviating the aforementioned changes caused by CY. Overall, the data suggested that MAT therapy could enhance hepatocyte defenses against CY-induced necroptosis and inflammatory responses by regulating mitochondrial Ca2+ homeostasis and inhibiting the ROS-NF-κB-RIPK3/MLKL signaling cascade. This study elucidated the potential benefits of employing MAT to protect farmed fish from agrobiological hazards during CY exposure, underscoring the practical applications of MAT in aquaculture.

Quercetin microgels alter gut metabolome and reverse oxidative damage invitro

Colonic delivery of quercetin using encapsulation techniques is an effective approach in maximizing quercetin efficacy against oxidative-stress related diseases such as inflammatory bowel disease. We hypothesized that colon-targeted delivery of quercetin with quercetin loaded alginate-chitosan microgels (ALQ) could alter colonic microbial metabolism regulating microbial metabolites production that may exert biological effects at the cellular level. To demonstrate this, ALQ were subjected to colonic fermentation using human fecal microbiota with empty microgels (AL) as control, and fermented fecal samples were collected at 0, 8, and 24 h. Short chain fatty acid analysis using gas chromatography showed that ALQ increased productions of acetic acid, while decreased isobutyric and isovaleric acid production. Semi-targeted metabolome scanning using Orbitrap mass spectrometer showed that the overall metabolome profile was remarkably different between AL and ALQ treatments at both 8 h and 24 h of fermentation. There were 9 metabolites at 8 h, and 54 metabolites at 24 h that were significantly regulated with more than 2-fold changes between AL and ALQ treatments. The metabolites included quercetin derived metabolites, amino acids and their derivatives, nucleotide derivatives, and organic acids. ALQ significantly modulated tyrosine metabolism, amino acids metabolic pathways, and the tricarboxylic acid cycle. These ALQ modulated metabolites in turn protected the Caco-2 cells from lipopolysaccharides induced injury, increased cellular antioxidant activities, and alleviated lipid oxidation induced by H2O2. Conclusively, ALQ could alter human fecal metabolome in vitro with significant shifts in key metabolites and exert antioxidant effects on cellular level, exhibiting potentials in colonic disease management.