Search Results (7,814)

Zinc deficiency is increasingly recognized as a risk factor for neurodegenerative diseases, yet the underlying molecular mechanisms remain incompletely understood. In this study, we investigated the impact of intracellular zinc depletion on oxidative stress and inflammasome activation in microglial (SIM-A9) and neuronal (SH-SY5Y) cell models, and evaluated the protective effects of polyphenolic compounds. Intracellular zinc chelation with the membrane-permeable chelator TPEN markedly increased reactive oxygen species (ROS) production, reduced cell viability, and upregulated the mRNA expression of NLRP3 inflammasome-related genes and pro-inflammatory cytokines. In contrast, extracellular zinc chelation had no effect, highlighting the critical role of intracellular zinc homeostasis in maintaining redox balance. Zinc supplementation significantly attenuated these responses. Among 32 polyphenols screened by DPPH radical scavenging assay, caffeic acid derivatives—chicoric acid (ChA), rosmarinic acid (RA), and caffeic acid phenethyl ester (CAPE)—exhibited the most potent antioxidant activity, surpassing that of edaravone. These compounds suppressed ROS production and differentially protected against zinc deficiency-induced cellular damage. ChA showed the strongest ROS inhibitory activity (IC50: 1.9 µM in SIM-A9), RA provided robust cytoprotection even at low concentrations, and CAPE most effectively suppressed inflammasome-related gene expression and inhibited aggregation of both Aβ1–42 and the highly neurotoxic pyroglutamate-modified variant pEAβ3–42. These findings demonstrate that intracellular zinc deficiency drives ROS-dependent upregulation of NLRP3 inflammasome-related genes, and suggest that caffeic acid derivative polyphenols may serve as complementary agents for mitigating neuroinflammatory and amyloidogenic processes relevant to Alzheimer’s disease. Full article

Natural microbial pigments offer important advantages and are widely studied for food applications. We investigated the biosynthetic pathways, characteristics, and bioactivities of the orange–red pigment produced by Bacillus velezensis YM–3, a strain isolated from the traditional Pixian Douban condiment. Whole-genome sequencing revealed complete pathways for melanin, phytoene, and heme biosynthesis. The purified extracellular pigment was characterized using ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and ultra-performance liquid chromatography–high-resolution mass spectrometry; it was preliminarily characterized as melanin-like pigment. The pigment was highly soluble in alkaline solutions, moderately soluble in water, and insoluble in common organic solvents. It exhibited strong photostability and remained stable at low temperature, precipitated under acidic conditions, and showed high stability under alkaline environments. Furthermore, the pigment demonstrated in vitro free radical scavenging activity. Hence, this study provides a scientific foundation for exploring the potential utility of B. velezensis YM–3 and its pigment metabolites as functional agents. Full article

To characterize intraspecific variation in phenolic acid composition and in vitro antioxidant capacity, color parameters, total phenolic contents (TPCs), hydrolyzable phenolic acid profiles, and DPPH and ABTS radical scavenging capacities were systematically determined in the flesh of 33 Cucurbita pepo accessions. All accessions exhibited bright yellow flesh, with significant variation in red-green value (a). TPC and antioxidant capacity differed markedly among accessions and generally followed right-skewed distributions, indicating that a limited number of accessions accumulated high levels of phenolics and antioxidant activity. Eight phenolic acids were quantified by high-performance liquid chromatography (HPLC), with p-hydroxybenzoic acid (8.97–341.98 μg/g), p-coumaric acid (2.42–761.88 μg/g), and ferulic acid identified as the major compounds. Ferulic acid and caffeic acid showed strong positive associations with both DPPH and ABTS scavenging capacities. Hierarchical clustering separated the accessions into two major groups, with Group 2 exhibiting higher TPC (208.89–657.69 µg GAE/g), total phenolic acid content (109.92–890.85 µg/g), and ABTS antioxidant capacity than Group 1. The high-antioxidant accessions may serve as promising candidates for antioxidant-enriched C. pepo products and quality-oriented breeding. Full article

Background: Type 2 diabetes mellitus (T2DM) is a global health challenge characterized by chronic hyperglycemia and oxidative stress. Pithecellobium dulce root has long been recognized for its antidiabetic potential; however, its specific bioactive constituents and mechanisms of action remain poorly defined. This study aimed to evaluate the antidiabetic and antioxidant properties of extracts and isolated molecules from P. dulce root bark. Methods: The DCM/MeOH crude extract of P. dulce root bark was fractionated with n-hexane (PDEH) and ethyl acetate (PDAE), followed by chromatographic purification and spectroscopic characterization, yielding seventeen compounds (1–17). The antioxidant activity (DPPH, ABTS, FRAP) and antidiabetic potential of PDEH, PDAE, and 1–17 were assessed in vitro using yeast-derived enzymes and in silico (targeting human α-glucosidase [PDB: 2QLY] and human α-amylase [PDB: 4GQR]). The in vitro α-glucosidase experiments used saccharomyces cerevisiae enzyme, which varies from the human target. Therefore, these results should be taken as preliminary screening data that needs confirmation with human enzymes. Results: Compound 1 was identified as new, while 2 was isolated for the first time from a natural source. The cell-free chemical tests DPPH, ABTS, and FRAP measured antioxidant capability. These tests quantify radical-scavenging and electron-transfer capabilities in vitro and are preliminary chemical screening methods. They do not directly represent biological antioxidant activity in cells or organisms. PDEH demonstrated strong radical scavenging against DPPH (IC₅₀ = 15.30 μg/mL) and ABTS (IC₅₀ = 12.80 μg/mL), while pristriol (16) showed ferric reducing power (EC₅₀ = 4200 μM FeSO₄/g). Enzyme inhibition assays demonstrated activity against α-amylase (IC₅₀ 53.88–112.24 µg/mL; acarbose IC₅₀ = 91.20 µg/mL) and α-glucosidase (IC₅₀ 18.38–136.88 µg/mL; acarbose IC₅₀ = 11.31 µg/mL). Compounds 15, 1, and 2 showed superior activity compared to acarbose for α-amylase, with effect sizes (Cohen’s d) of 2.15, 0.94, and 0.82, respectively, and IC₅₀ values of 53.88, 88.15, and 92.62 µg/mL; for α-glucosidase, IC₅₀ values were 18.38, 39.25, and 36.40 µg/mL, respectively. Docking studies supported these findings, revealing binding energies of −9.08, −8.34, and −7.22 kcal/mol for compounds 1, 2, and 15 with α-amylase, and −10.35 and −9.79 kcal/mol for compounds 1 and 2 with α-glucosidase. ADME profiling further identified 1 and 2 as promising lead candidates for dual-enzyme inhibition. Conclusions: P. dulce root bark represents a potent source of bioactive molecules with both antioxidant and dual-enzyme-inhibitory properties. These findings validate its traditional use and highlight its potential in the development of multitarget therapies for T2DM management. Full article

Coffee is an important dietary source of bioactive antioxidant compounds contributing to the antioxidant properties of coffee beverages. While brewing affects yield of total antioxidants, it is still not really clear which individual (phenolic) compounds contribute to the antioxidant activity the most. A method combining chromatographic separation and individual antioxidant evaluation might therefore be useful. This study aimed at evaluating the antioxidant potential of the compounds in coffee beverages using a high-performance liquid chromatography approach directly coupled to the well-known trolox equivalent antioxidative capacity (TEAC) assay (HPLC-onlineTEAC). The study further evaluated the influence of different brewing methods (‘Americano’, ‘V60’, ‘French press’, and ‘cold brew’) on the bioactive compound profile and antioxidant potential of Arabica coffee beverages. The brewing method significantly affected caffeine content, chlorogenic acid composition, total phenolic content (TPC), and antioxidant activity of the analyzed beverages (p < 0.05). Cold brew samples exhibited the highest total radical scavenging activity and concentrations of major caffeoylquinic acid isomers (3-CQA, 4-CQA, and 5-CQA). In contrast, “French-pressed” beverages were characterized by the highest TPC values, while V60 samples generally showed the lowest antioxidant-related parameters. Chlorogenic acids accounted for more than 84% of the total antioxidant potential of all analyzed beverages, whereas monocaffeoylquinic acids represented the dominant fraction responsible for radical-scavenging activity. The results indicate that prolonged low-temperature extraction favors the recovery and preservation of highly reactive chlorogenic acid isomers and contributes to the enhanced antioxidant potential of coffee beverages, beyond the effect of coffee dose alone. Full article

Ganoderma lucidum spores protein (GLSP) holds significant potential for providing antioxidant peptides. We employed in silico enzymatic hydrolysis to generate small peptide fragments by specific proteins. Through fast computer screening and molecular docking with Keap1 receptor, we identified two potential antioxidant peptides, KAF (Lys-Ala-Phe) and NDSF (Asn-Asp-Ser-Phe), from 1171 candidates after efficient hydrolysis by pepsin and proteinase K. Molecular docking result showed both of them could bind onto the Leu557, Ala 510 and Val512 of bioactive pockets of Keap1 through hydrogen bonds and NDSF had lower docking energy (−85.6073 kcal/mol). The in vitro antioxidant validation indicated both of them could eliminate DPPH and ABTS radicals dramatically, and NDSF had a stronger scavenging capacity on DPPH (IC₅₀ = 35.1 μg/mL) and ABTS (IC₅₀ = 55.9 μg/mL), respectively. Quantitative chemical analysis further revealed that the key antioxidant active sites of NDSF were located at O18 of Ser amino side chain, and N9 of Lys terminal amino residue for KAF. Furthermore, in the cellular experiments, NDSF and KAF effectively increased the activities of antioxidant enzymes such as SOD, CAT, and GPx, while also reducing the level of MDA. Together, these findings highlight the potential of Ganoderma lucidum spore proteins as a source for the rapid identification of antioxidant peptides. The two selected peptides, therefore, s hold promising prospects for applications in functional foods and health products. Full article

Skin aging is associated with oxidative stress, extracellular matrix degradation, and dysregulation of melanogenesis, leading to wrinkles, loss of elasticity, and hyperpigmentation. Natural plant-derived compounds have attracted increasing interest as multifunctional cosmetic ingredients due to their antioxidant and anti-aging properties. Mai-Kae-Den-Klong (MKDK), a traditional Thai longevity herbal formula composed of Albizia procera (Roxb.) Benth., Cyperus rotundus L., Diospyros rhodocalyx Kurz, Piper nigrum L., Streblus asper Lour., and Tinospora crispa (L.) Hook.f. & Thomson, has historically been used to promote vitality and healthy aging; however, its potential application as a cosmetic anti-aging ingredient remains scientifically unexplored. Therefore, this study investigated the anti-aging potential of MKDK extract using integrated enzyme-based bioassays and in silico approaches. Phytochemical profiling of the ethanolic extract was performed using LC-MS analysis, revealing diverse bioactive constituents, including flavonoids, phenolic glycosides, alkaloids, and terpenoids, with (−)-epicatechin, procyanidin B1, and piperine identified as major metabolites. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, while inhibitory activities against tyrosinase, collagenase, elastase, and hyaluronidase were assessed to determine skin anti-aging potential. The extract exhibited strong antioxidant activity, with IC₅₀ values of 17.23 ± 2.11 µg/mL for DPPH and 11.87 ± 1.77 µg/mL for ABTS assays. In addition, the extract demonstrated inhibitory effects against tyrosinase (IC₅₀ = 41.25 ± 1.56 µg/mL), elastase (IC₅₀ = 49.51 ± 3.69 µg/mL), collagenase (IC₅₀ = 61.54 ± 2.88 µg/mL), and hyaluronidase (IC₅₀ = 63.74 ± 6.32 µg/mL), suggesting multifunctional anti-aging properties associated with skin brightening and extracellular matrix preservation. Network pharmacology analysis predicted multiple aging-related signaling pathways, particularly the FoxO signaling pathway, which is associated with oxidative stress regulation and longevity. Molecular docking analysis further demonstrated favorable binding affinities of procyanidin B1, epicatechin, and piperine toward skin-aging-related enzymes, supporting their potential contribution to the observed bioactivities. Overall, these findings suggest that MKDK possesses promising cosmeceutical potential as a natural multifunctional anti-aging ingredient and provides scientific support for the application of traditional Thai herbal formulations in cosmetic and skin health products. Full article

The consumption of vegetable oils is steadily increasing, especially in Asian countries. Once used, the utilized cooking oils are either thrown into landfills or dumped there, endangering both the environment and people. One common method is to convert waste cooking oil (WCO) into biofuel; however, since WCO contains many free radicals, burning it releases large quantities of pollutants, meaning that disposal of WCO poses significant environmental risks. To stabilize the WCO (Cocos nucifera) before converting it into biofuel, this study analyzed the extraction, optimization, and use of antioxidant-rich bio-oil from Anisomeles malabarica leaves as a natural additive. Solvent screening revealed that a hexane–ethanol ratio of 4:2 was optimal for generating 76.7% bio-oil at room temperature. A maximum yield of 77% was attained by temperature and time optimization, which determined that 50 °C and 20 min were ideal. The extraction exhibits zero-order kinetics during the increasing phase, according to kinetic studies, with rate constants ranging from 0.54 to 1.44% min⁻¹ (R² = 0.950–0.997). The Peleg equilibrium model (average R² = 0.806) was used to describe the extraction profile. The regression equation ln(k) = 1799.3 × (1/T) − 10.828 (R² = 0.9748, p = 0.0002) was obtained using Arrhenius analysis. It was found that the compounds responsible for the antioxidant scavenging activity were found to be phytol, hexadecenoic acid, and tocopherol (vitamin E). The DPPH (2,2-diphenyl-1-picrylhydrazyl) test confirmed that 3% (v/v) bio-oil scavenged about 95% of free radicals, whereas the conjugated diene experiment demonstrated that over 90% of lipid oxidation in WCO was prevented. The combustion and emission properties of biofuel (WCB), which was created by transesterifying bio-oil-treated WCO, were compared to those of neat diesel and untreated WCO-derived biofuel (WC). In comparison to both WC50 and neat diesel, WCB50 demonstrated an equivalent in-cylinder pressure and heat release rate, but significantly reduced emissions of NO_x, CO, hydrocarbons, and smoke. These results show that Anisomeles malabarica bio-oil works well as a natural antioxidant addition for clean combustion and biodiesel stabilization. Full article

Fruit and vegetable juices are ideal probiotic carriers and pectin supplementation is promising for probiotic survival. In this study, we investigated the effects of high- and low-methoxyl pectin on Lacticaseibacillus casei 37 and Lactobacillus helveticus 76 in fermented pear juice (PJ) regarding fermentation, viability, and functionality. Our results showed that pectin protected probiotic viability at 4 °C for 28 days, with viable cell counts reaching 8.39–8.63 log colony-forming units/mL. Furthermore, it promoted phenolic compound release (e.g., gallic acid and protocatechuic acid), raising total phenolic content by 8.3–21.9% and total flavonoid content by 79.6–140.3%. It significantly enhanced DPPH, ABTS radical scavenging activity, and FRAP antioxidant capacity. In vitro digestion revealed that pectin supplementation elevated the survival rate of probiotics in simulated gastric juice by 6.2–66.4%. Additionally, correlation analysis linked specific phenolics (p-coumaric acid, epicatechin, rutin) to antioxidant activity. An addition of 0.3% low-methoxyl and 0.2% high-methoxyl pectin was considered the optimal treatment, benefiting probiotic viability, phenolic accumulation and antioxidant stability of fermented PJ under cold storage and gastrointestinal environment. Thus, pectin is an effective carrier for high-viability, high-antioxidant probiotic fermented PJ beverages. Full article

Background/Objectives: Tuberculosis remains a major public health challenge due to the persistence of Mycobacterium tuberculosis (Mtb) and the emergence of multidrug-resistant strains. In this study, Pep-H, an HNP-1-derived antimicrobial peptide with the sequence RRYGTCIYQGRLWAF-NH₂, was used as a compact scaffold to examine how single-residue substitutions at the Cys position affected its biological and functional profile. Methods: A focused single-position substitution panel was generated by replacing Cys with Trp, Ala, Arg, or Met while preserving peptide length and sequence context, and the analogs were computationally prioritized according to their predicted antitubercular potential and contrasting side-chain properties. The peptides were synthesized, purified, characterized by HPLC and mass spectrometry, and evaluated for activity against Mtb H37Rv, cytotoxicity, hemolysis, ethidium bromide accumulation, and DPPH radical scavenging. Results: Pep-H retained the most favorable profile, showing the highest antimycobacterial potency, low hemolysis, favorable selectivity indices, enhanced ethidium bromide accumulation, and the strongest antioxidant response. All Cys substitutions reduced antimycobacterial activity, indicating that none of the tested residues reproduced the integrated biological profile of Pep-H. Conclusions: The contrasting outcomes of the Arg- and Met-containing analogs suggest that increased cationicity or sulfur retention alone was insufficient, while supporting a multifactorial contribution of Cys side-chain chemistry and the local GTCIY environment. Full article

Background/Objectives: Vitex agnus-castus L. is a well-known medicinal herb shown to be effective in treating gynecological disorders. However, no systematic comparative studies have been conducted between V. agnus-castus leaf extract (VACLE) and Vitex agnus-castus seed extract (VACSE). We performed gas chromatography–mass spectrometry (GC–MS) analysis of VACLE and VACSE and measured total phenolic and flavonoid contents. Methods: The bioactivity testing included antioxidants, antibacterial, antifungal, anticancer, and antidiabetic activities. Results: A total of 55 GC–MS compounds were identified in VACLE and 34 in VACSE; isoamyl formate (27.96%) and a pyranone derivative (14.11%) were detected exclusively in VACLE, whereas cis-linoleic acid (40.58%) and palmitic acid (21.87%) predominated in VACSE. VACLE showed significantly higher TPC (94.12 vs. 54.12 mg GAE/g DW) and TFC (82.00 vs. 42.00 mg QE/g DW). The VACLE demonstrated moderate antioxidant activity and generally stronger bioactivity than VACSE, as evidenced by its lower ABTS⁺ radical scavenging IC₅₀ value (55 vs. 70 μg/mL), antibacterial activity (MIC: 6.25–50 vs. 12.5–100 μg/mL), anticancer activity against HepG2 cells (IC₅₀: 93.2 vs. 247.5 μg/mL), and antidiabetic activity through α-amylase inhibition (IC₅₀: 28.7 vs. 70.1 μg/mL). VACSE exhibited greater antifungal activity than VACLE against all tested Candida strains, with the highest activity observed against C. parapsilosis (MIC: 6.25 ± 2.26 μg/mL). VACLE induced transcriptional changes consistent with caspase-mediated apoptosis, characterized by increased expression of caspase-8, caspase-9, and Bax and decreased expression of Bcl-2/Bcl-xL, pending protein-level confirmation. Conclusions: In conclusion, VACLE exhibits notable antioxidant, antibacterial, anticancer, and antidiabetic properties, whereas VACSE shows greater antifungal activity. These findings highlight tissue-specific differences in phytochemical composition and in vitro biological activities and provide a basis for future studies involving compound isolation, mechanistic validation, toxicity assessment, and in vivo evaluation. Full article

Cyclocarya paliurus leaves, commonly consumed as “sweet tea”, remain underutilized after spring harvest. This pilot study investigated harvest month-associated changes in bioactivity-related properties and volatile profiles of mature leaves collected from May to September (Q5–Q9) at one site in 2024. Aqueous extracts were analyzed for TPC, TFC, TP, TSC, DPPH and ABTS•+ radical scavenging activities, and inhibition of advanced glycation end-products (AGEs) formation in glucose/fructose-BSA models, with aminoguanidine as a positive reference. Dried leaf powders were profiled by SPME-GC-MS for tentative VOC annotation. TPC, TFC, TP, and TSC ranged from 28.04 to 28.87, 15.42 to 40.22, 2.14 to 2.51, and 23.15 to 25.30 mg/g, respectively. Q9 showed the strongest radical scavenging response, with the lowest DPPH and ABTS•+ IC50 values (0.119 and 0.131 mg/mL), while Q6 also exhibited relatively strong activity. Furthermore, Q6 and Q9 exhibited superior advanced glycation end-product (AGE) inhibitory responses, with Q9 being particularly effective in the fructose-BSA model. VOC profiles varied markedly by month, shifting from alkene/terpene predominance in Q5–Q6 to alcohol enrichment in Q7 and renewed alkene/terpene predominance in Q9. Integrated heatmap and Pearson correlation analyses identified clear temporal co-variations and pairwise associations between distinct VOC classes and bioactivity indices. Collectively, these results provide preliminary, site- and year-specific evidence that harvest month is associated with changes in the bioactivity-related properties and aroma-related phytochemical profiles of mature C. paliurus leaves, offering a cautious reference for harvest-stage-oriented utilization. Full article

Geisha coffee (Coffea arabica L. cv. Geisha) is internationally recognized for its exceptional sensory quality; however, its functional properties and bioactive composition remain insufficiently explored. This study evaluated the phytochemical profile, antioxidant capacity, vascular bioactivity, and toxicological safety of an aqueous extract of roasted Geisha coffee (AErGC) from the Chiriquí highlands, Panama. The chemical composition was determined using HPLC-PDA. Antioxidant activity was assessed using DPPH, ABTS, and lipid peroxidation assays. Vascular effects were studied in rat aortic rings, and safety was evaluated through Artemia salina and a single-dose acute oral toxicity model in rats (OECD 423). Chemical characterization was performed by HPLC-PDA, revealing notably elevated levels of caffeine (69.5 ± 6.4 mg/g) and 5-O-caffeoylquinic acid (74.5 ± 6.9 mg/g). The extract exhibited strong free radical scavenging capacity, with an IC₅₀ value of 14.7 ± 4.9 µg/mL in the DPPH assay, and inhibited lipid peroxidation by 72.71 ± 1.63% at 15.6 µg/mL. In endothelium-intact rings, AErGC induced a concentration-dependent vasorelaxant effect, reaching a maximum relaxation of 70.84 ± 2.9%. Toxicological results showed an LC₅₀ > 1000 µg/mL in A. salina and an oral LD₅₀ > 2000 mg/kg, classifying the extract as Category 5 (low toxicity). These findings highlight Panamanian Geisha coffee as a promising functional beverage with antioxidant and vascular protective properties, supporting its potential as a nutraceutical. Full article

This study investigates the effect of hot-air drying temperature (45–70 °C) on the major bioactive constituents and in vitro antioxidant activity of artificially cultivated Sanghuangporus vaninii fruiting bodies. The contents of polyphenols and polysaccharides gradually rose with elevated temperature and peaked at 70 °C, whereas the flavonoid content reached the maximum at 55 °C and declined continuously afterwards. Among the tested bioactive substances, polyphenols exhibited the strongest antioxidant activity, with their DPPH and superoxide anion radical scavenging capacities peaking at 70 °C and hydroxyl radical scavenging capacity peaking at 55 °C. Correlation analysis revealed that the contents of polyphenol and polysaccharide possessed markedly positive correlations with DPPH and superoxide anion scavenging activities, yet no statistically relevant correlation was observed for flavonoids. Cluster analysis classified all tested temperatures into two clusters: low-temperature drying (45–50 °C) yielded inferior bioactive constituents and antioxidant activity, whereas medium-to-high-temperature drying (55–70 °C) delivered superior performance. From a practical perspective, drying at temperatures ≥55 °C is recommended to enhance product quality. Specifically, 70 °C is optimal to maximize overall antioxidant capacity, whereas 55 °C is preferable for flavonoid enrichment and color preservation. These findings provide an evidence-based strategy for the optimization of post-harvest drying processes of S. vaninii. Full article

Naturally fermented tofu whey is a nutrient-rich byproduct of tofu production that harbors diverse lactic acid bacteria (LAB) with potential probiotic properties. However, the antioxidant mechanisms of these LAB, particularly the roles of different cellular fractions and their metabolic basis, remain unclear. This study aimed to isolate LAB from naturally fermented tofu whey and evaluate their antioxidant activities across cellular fractions, combining in vitro assays, 16S rDNA-based identification, metabolomic profiling, and cellular validation to elucidate the underlying mechanisms. Six LAB strains were isolated and screened for 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging capacity and environmental stress tolerance. Among the identified isolates, Lactiplantibacillus plantarum MCS1903 exhibited the highest extracellular antioxidant activity. Non-targeted metabolomic analysis of cell-free supernatant revealed distinct metabolic profiles compared with the MRS control, with significant enrichment of antioxidant-related metabolites and pathways. In Caco-2 cells, MCS1903 supernatant (<5%, v/v) showed no significant cytotoxicity and effectively alleviated H₂O₂-induced oxidative stress by modulating the Nrf2/Keap1-HO-1 signaling pathway. These findings indicate that tofu whey is a valuable source of functional LAB, and MCS1903 represents a promising candidate for probiotic and functional food applications, supporting the valorization of tofu whey and development of natural antioxidant probiotics derived from fermented food byproducts. Full article