Search Results (10,733)

Chili pepper (Capsicum annuum L.) is a globally significant economic crop, however long-term continuous cropping often induces multifaceted constraints including soil nutrient depletion, rhizosphere microbial imbalance, and pathogen accumulation, which collectively exacerbate soil-borne diseases and substantially reduce yield. Incorporating rice (Oryza sativa L.) into rotation increases the diversity of the cultivation environment and represents a cost-effective strategy to mitigate continuous-cropping obstacles. Therefore, evaluating and elucidating the role and underlying mechanisms of the chili pepper–rice rotation system in improving soil conditions and alleviating continuous cropping obstacles in chili pepper holds significant importance. This study conducted a two-year field experiment from 2023 to 2024, setting up chili pepper–rice rotation (RVR) and chili continuous cropping (CCV) treatments, to systematically analyze the effects of chili pepper–rice rotation on chili pepper yield, disease occurrence, soil nutrients, and rhizosphere microbial communities. Across 2023–2024, RVR significantly reduced the incidence of bacterial wilt and root rot, increasing yield by 10.60% in 2023 and by 61.07% in 2024 relative to CCV. Analysis of soil physicochemical properties revealed that RVR significantly promoted the accumulation of available nitrogen, phosphorus, and potassium in the soil, as well as enhanced nutrient-acquisition enzyme activity, effectively alleviating the carbon and phosphorus limitations faced by rhizosphere microorganisms. Rhizosphere microbial analysis indicated that under the RVR treatment, the abundance of pathogen-associated taxa such as Ralstonia and Fusarium significantly decreased. The co-occurrence network modularity increased, and the negative cohesion of pathogens was strengthened, thereby inhibiting pathogen expansion. Further random forest and correlation analyses demonstrated that RVR significantly contributed to yield formation by optimizing fungal metabolic pathways, such as galactose degradation, sulfate reduction, and L-tryptophan degradation. In conclusion, the chili pepper–rice rotation significantly alleviates continuous cropping obstacles and enhances yield by improving nutrient supply and regulating microbial community composition, as well as the topological structure and functional relationships of their co-occurrence networks, particularly by strengthening the role of fungi in community function and metabolic regulation. This study provides a theoretical basis for the biological and soil regulation of pepper continuous cropping obstacles and offers a feasible pathway for sustainable cultivation and green control strategies. Full article

This study investigated gluten- and lactose-free cookies enriched with pomegranate seed flour (PSF, 5 and 10% w/w), a sustainable by-product of juice processing. LC-ESI/HRMS/MS analysis of PSF identified 36 bioactive compounds, mainly flavonoids, phenolic acids, hydrolysable tannins, and polar lipids. PSF incorporation significantly affected colour and texture, increasing friability, as evidenced by a reduction in breaking force from 35.37 N in the control cookie to 21.72 N in cookies enriched with 10% PSF, while maintaining good sensory acceptability. Total phenol (≈1.60–1.82 mg GAE/g) and flavonoid contents were only slightly affected by PSF addition; however, antioxidant activity markedly increased, with FRAP values rising from 55.8 to 67.82 μM Fe (II)/g and DPPH IC₅₀ values decreasing from 31.38 to 12.72 μg/mL in the 10% PSF-enriched cookies. The enriched cookies inhibited pancreatic lipase, α-amylase, and α-glucosidase in a clear concentration-dependent manner and showed a reduced predicted glycaemic index (pGI 46.80 vs. 50.08 in the control). Multivariate analysis confirmed a clear dose-dependent effect of PSF on functional, textural, and sensory properties. Overall, pomegranate seed flour proved to be an effective upcycled ingredient for enhancing the functional profile of gluten- and lactose-free bakery products. Further studies using digestion models and in vivo or clinical approaches are needed to clarify the nutritional relevance and health effects of PSF-enriched foods. Full article

Salt stress is one of the main abiotic stresses that restrict crop production. Melatonin (MT), a signal molecule widely present in plants, plays an important role in regulating abiotic stress response. In this study, celery seedlings were used as experimental materials, and the control, salt stress, and exogenous MT treatment groups under salt stress were set up. Through phenotypic, physiological index determination, transcriptome sequencing, and expression analysis, the alleviation effects of MT on salt stress were comprehensively investigated. The results showed that exogenous MT treatment significantly reduced seedling growth inhibition caused by salt stress. Physiological measurements showed that MT significantly reduced malondialdehyde content, increased the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), promoted the accumulation of free proline and soluble protein, and increased photosynthetic parameters such as chlorophyll, ΦPSII, Fv/Fm, and ETR. Transcriptome analysis showed that MT regulates the expression of several genes associated with carbon metabolism, including β-amylase gene (AgBAM), sucrose-degrading enzyme genes (AgSUS, AgINV), and glucose synthesis-related genes (AgAG, AgEGLC, AgBGLU). The results of qRT-PCR verification were highly consistent with the transcriptome sequencing data, revealing that MT synergistically regulates starch and sucrose metabolic pathways, and effectively alleviates the damage of celery seedlings under salt stress at the molecular level. In summary, exogenous MT significantly improved the salt tolerance of celery by enhancing antioxidant capacity, maintaining photosynthetic function, promoting the accumulation of osmotic adjustment substances, and synergistically regulating carbon metabolism-related pathways. The concentration of 200 μM was identified as optimal, based on its most pronounced alleviating effects across the physiological parameters measured. This study provides an important theoretical basis for utilizing MT to enhance plant salt resistance. Full article

Background: Streptococcus pneumoniae (Spn) is a leading bacterial pathogen responsible for severe invasive diseases, including meningitis, sepsis, and pneumonia. Current pneumococcal vaccines, which are all based on capsular polysaccharide antigens, provide limited protection and are further compromised by post-vaccination serotype replacement. Pneumococcal surface protein A (PspA), a highly conserved virulence factor expressed across diverse serotypes, has emerged as a promising candidate antigen for novel protein-based vaccines. However, progress in this field has been hindered by the absence of standardized in vitro functional antibody assays. Methods: This study established a robust functional antibody detection method for PspA-based protein vaccines by modifying the conventional multiplex opsonophagocytic killing assay (MOPA), originally designed for polysaccharide-based vaccines. Using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) typing, a target strain panel was selected and developed to include representative strains from PspA Family 1-Clade 2 and Family 2-Clades 3 and 4. The MOPA protocol was optimized by extending the phagocytic reaction time to enhance sensitivity. Specificity was confirmed through recombinant PspA competitive inhibition assays. Results: The assay demonstrated high linearity (R² ≥ 0.98) between opsonophagocytic index (OI) and serum dilution, along with acceptable repeatability (CV ≤ 30%) and intermediate precision (CV ≤ 50%). Both preclinical and clinical serum samples exhibited potent bactericidal activity against diverse PspA families, independent of capsule type. Conclusions: This study provided a standardized framework to support the development and regulatory assessment of protein-based pneumococcal vaccines. Full article

Arthritis in K/BxN mice is provoked by pathogenic autoantibodies to glucose-6-phosphate isomerase (G6PI), which is a ubiquitously expressed enzyme that is present in cells, in the circulation and on the articular cartilage. When G6PI autoantibodies (auto-Abs) deposit on the articular cartilage of K/BxN mice, arthritis ensues due to the activation of various components of the innate immune system. Recent studies have investigated the in vivo efficacy of recombinant fragment-crystallizable (Fc) protein-based therapeutics. Many of the recombinant Fc proteins that have been evaluated have been shown to have a protective effect in mouse models of arthritis, such as the K/BxN serum-transfer model. More recently, rFc-µTP-L309C, a recombinant human IgG1-Fc with an additional point mutation at position L309C fused to the human IgM tailpiece to form a hexamer, has been shown to ameliorate the arthritis in K/BxN mice. Additional studies have shown that rFc-µTP-L309C has multiple effects that work together to ameliorate the arthritis, including inhibition of neutrophil migration into the joint, inhibition of IL-1β production, downregulation of Th1 and Th17 cells and increases in T regulatory cells and synovial fluid IL-10. In this work, rFc-µTP-L309C was shown to effectively prevent arthritis in the K/BxN serum-transfer model, significantly downregulate inflammatory cytokines/chemokines and ameliorate the arthritis in the endogenous K/BxN model. This amelioration of the arthritis was mediated by a significant decrease in antibody levels. Interestingly, this effect seems to be independent of the neonatal Fc receptor (FcRn). rFc-µTP-L309C was shown to specifically inhibit G6PI autoantibody secretion from B-cells with a concomitant increase in TGFβ and decrease in B-cell activating factor (BAFF). These new findings suggest that rFc-µTP-L309C may provide a therapeutic benefit for other antibody-mediated autoimmune disease through its effects on B-cells. Full article

Polyoxometalates (POMs) exhibit significant potential for application in Alzheimer’s disease (AD) therapeutics owing to their inherent chemical and physical properties and structural tunability. Through transition metal substitution, functional modification, and the construction of POMs-based nanocomposites, POMs can precisely recognize and effectively modulate various key pathogenic proteins involved in Alzheimer’s disease. They can also intervene in disease progression through multiple mechanisms, including inhibition of Aβ aggregation, disaggregation of amyloid-β (Aβ), scavenging of reactive oxygen species (ROS), hydrolytic activity, and modulation of enzyme function. In addition, due to their outstanding physicochemical properties, the application of POMs in phototherapy has emerged as a significant direction in AD treatment research. This review systematically summarizes recent advances from 2011 to 2025 in POMs targeting key pathogenic proteins in AD, comprehensively analyzes their specific mechanisms of action across different therapeutic contexts, highlights their significant advantages and broad potential in AD treatment, and provides new insights for the future structural design, functional optimization, and clinical translation of POMs. Full article

The hypothalamic–pituitary–adrenal (HPA) axis plays a pivotal role in regulating stress responses through ACTH-stimulated glucocorticoid production. The transcriptional programmes underlying temporal adaptation to prolonged ACTH exposure and glucocorticoid feedback remain incompletely characterized. Adult male Wistar rats were subjected to acute ACTH stimulation (single injection, 1 h) to elicit an immediate transcriptional response, prolonged ACTH exposure (three injections over 36 h) as a repeated exposure, or Dexamethasone treatment (three injections over 36 h). Plasma corticosterone levels were subsequently measured using an enzyme-linked immunosorbent assay (ELISA). The adrenal transcriptome profiling was performed using Affymetrix arrays. Differentially expressed genes (DEGs; |fold change| ≥ 1.8, adjusted p < 0.05) were analyzed using limma, followed by pathway and network analyses. Acute ACTH exposure resulted in the induction of 569 DEGs (357 upregulated), including immediate-early genes (Nr4a family, AP-1 factors), cAMP-PKA-CREB signalling components, and heat shock proteins. Prolonged ACTH resulted in 98 DEGs (predominantly downregulated), including the suppression of mitochondrial genes and upregulation of Polycomb repressive complex 2 components, suggesting epigenetic transcriptional attenuation. Dexamethasone treatment yielded 75 DEGs with selective suppression of SREBP-mediated cholesterol biosynthesis and uptake pathways. Twelve genes were downregulated by both prolonged ACTH and Dexamethasone, including sterol metabolism and interferon-stimulated genes. Acute and prolonged ACTH exposure engage distinct transcriptional programmes. Acute stimulation activates immediate-early genes and stress responses, while prolonged exposure suppresses mitochondrial gene expression through transcriptional dampening mechanisms. Dexamethasone is associated with the inhibition of cholesterol metabolism via SREBP pathway suppression. These findings illuminate HPA axis adaptation and glucocorticoid-induced adrenal suppression. Full article

In this study, we designed and synthesized 11 N-aryl-S-aryl-2-mercaptoacetamide derivatives as new tyrosinase inhibitors (TYRIs). Experiments with pyrocatechol violet confirmed that four derivatives showed copper-chelating abilities similar to or superior to those of well-known copper-chelating TYRIs like kojic acid (KA) and N-phenylthiourea. However, these four derivatives showed little or no inhibition of mushroom TYR (mTYR) activity and melanin production in B16F10 cells. Instead, derivatives with low copper chelation ability exhibited potent inhibitory effects on mTYR activity and melanin production in B16F10 cells. These findings suggest that the results of metal ion chelation by inhibitors in an enzyme-free environment do not always match those under metalloenzyme conditions because of the interactions between inhibitors and amino acid residues around the metalloenzyme active site. Owing to their favorable interactions with amino acids in the mTYR active site, two of the derivatives inhibited mTYR more effectively than KA. Probably for the same reason, three derivatives inhibited B16F10 cellular TYR more effectively than KA, and one derivative inhibited pigment production in zebrafish larvae much better than KA. This last derivative, which effectively exhibits TYR-inhibitory activity and suppresses melanin production in several species, is considered a promising compound for use as a TYRI in various fields. Full article

Glutamine is a known regulator of vascular smooth muscle cell (VSMC) function, but the molecular pathways underlying this response remain incompletely understood. This study investigated how glutamine metabolism influences VSMC behavior and identified the responsible enzymes and metabolites. Glutamine deprivation markedly reduced VSMC proliferation, migration, and collagen synthesis, while modestly decreasing viability. Pharmacological inhibition of glutaminase-1 (GLS1) or aminotransferases (AT) similarly suppressed these cellular functions, whereas inhibiting glutamate dehydrogenase 1 (GLUD1) had no effect. Metabolite analysis revealed that glutamine deprivation or AT inhibition, but not GLUD1 inhibition, reduced intracellular α-ketoglutarate (αKG) concentrations, establishing AT as the primary enzyme converting glutamine-derived glutamate to αKG. To identify which metabolite drives VSMC responses, glutamine-starved cells were supplemented with various glutamine-derived molecules. The cell-permeable αKG analog dimethyl-αKG significantly restored VSMC proliferation, migration, collagen synthesis, and survival, while ammonia only enhanced viability, demonstrating αKG’s primary role in mediating glutamine-dependent functions. These findings establish that glutamine metabolism via the GLS1-AT-αKG pathway is a critical driver of VSMC activation and survival. Targeting this glutamine-αKG metabolic axis through GLS1 inhibition, AT blockade, or downstream αKG disruption offers a compelling therapeutic strategy for ameliorating fibroproliferative vascular diseases, including atherosclerosis, post-angioplasty restenosis, and pulmonary hypertension. Full article

Traditional macrolide antimicrobials are inhibitors of cytochrome P4503A (CYP3A) in cattle liver. Monensin (MON), an ionophore with a narrow safety margin, undergoes CYP3A-dependent O-demethylation, and its incompatibility with macrolides is well recognized in livestock animals. This study evaluated the effects of newer macrolides—tilmicosin (TIL), tulathromycin (TUL), and gamithromycin (GAM)—on CYP3A-dependent metabolism in bovine liver microsomes and examined how these drugs influence MON hepatic metabolism. Molecular docking studies were also performed to predict their interactions with CYP3A enzymes. The CYP3A-dependent enzyme activity, testosterone 6β-hydroxylase, was inhibited in the presence of triacetyl-oleandomycin (used as a reference macrolide), as well as with MON. None of the other macrolides tested affected this enzymatic activity. All macrolides inhibited MON metabolism, but the extent of inhibition observed with triacetyl-oleandomycin was higher than that produced by TIL, TUL, and GAM. Molecular docking analyses indicated that triacetyl-oleandomycin and MON exhibited the highest binding affinities for the active site of CYP3A isozymes, compared with TIL, TUL, and GAM. The agreement between enzymatic data and in silico predictions indicates that TIL, TUL, and GAM are weaker inhibitors of CYP3A-mediated MON metabolism. The modest reduction in MON hepatic metabolism caused by these macrolides—commonly used in cattle feedlots—suggests a low likelihood of clinically relevant drug–drug interactions under typical dosing conditions. Full article

Mycobacterium tuberculosis (M. tuberculosis) relies on the thioredoxin (Trx)–thioredoxin reductase (TrxR) system to maintain intracellular redox homeostasis and to support Trx-dependent DNA synthesis and repair, making TrxR a potential target for anti-tuberculosis therapy. Gold nanoclusters have been reported to inhibit human TrxR and suppress tumor growth, suggesting that gold-based nanomaterials can modulate TrxR activity. In this study, we report a previously uncharacterized oxidized crystal structure of M. tuberculosis TrxR containing two dimers in the asymmetric unit and use this structure to investigate inhibition by a glutathione-coated gold nanocluster (GSH-AuNC). Biolayer interferometry and enzymatic assays show that GSH-AuNC binds directly to M. tuberculosis TrxR and efficiently inhibits its catalytic activity at the purified enzyme level. Molecular dynamics simulations indicate that GSH-AuNC can occupy a surface pocket proximal to the active site, providing a plausible structural basis for enzyme engagement. AlphaFold3 modeling of the M. tuberculosis TrxR-Trx heterodimeric complex defines the interaction interface required for productive electron transfer and provides a structural hypothesis for how GSH-AuNC disrupts this process. Together, these results provide structural and mechanistic insights into the biochemical modulation of M. tuberculosis TrxR by GSH-AuNC, while the antimycobacterial activity of GSH-AuNC remains to be evaluated in future studies. Full article

Hyaluronic acid (HA) injections are commonly employed in the management of osteoarthritis (OA), yet their therapeutic benefits are often limited by oxidative degradation and enzymatic breakdown within the joint. This study investigates whether Resolvin D1, Resolvin D2, and their methyl ester derivatives can enhance the efficacy of HA injections by acting as dual-function agents with both antioxidant and enzyme inhibitory properties. A comprehensive series of in vitro assays—including ORAC, FRAP, DPPH, ABTS, HRS, and SOD—were performed to evaluate antioxidant capacity, using Trolox, Ascorbic acid, β-Carotene, and Quercetin as reference standards. The potential to inhibit HA degradation was assessed through ROS-induced HA fragmentation and hyaluronidase inhibition assay, with epigallocatechin gallate (EGCG) serving as a positive control. The results indicate that Resolvin derivatives, particularly the methyl ester form of Resolvin D1, display mechanism-dependent antioxidant activity, showing pronounced effects in hydrogen atom transfer-based assays (e.g., ORAC and HRS), as well as in ABTS^•+ and superoxide-related systems, along with protection against ROS and enzyme-induced HA degradation. These findings suggest that incorporating Resolvin derivatives may represent a promising strategy to improve HA-based viscosupplementation by enhancing stability and therapeutic persistence in osteoarthritic joints. Full article

Background/Objectives: Breast cancer cells rely on both mitochondrial metabolism and proteostatic mechanisms for cell fitness. The mitochondrial enzyme IDH2 supports redox balance and biosynthesis, while the ubiquitin-proteasome system (UPS) preserves protein quality. This study aimed to determine whether inhibiting IDH2 enhances sensitivity to proteasome-targeting agents across breast cancer subtypes. Methods: A panel of human and murine breast cancer cell lines was treated with the IDH2 inhibitor AGI-6780, alone or in combination with the proteasome inhibitor carfilzomib (CFZ) or the E1 ubiquitin-activating enzyme inhibitor TAK-243. Synergy was evaluated using Bliss scoring. Apoptosis, clonogenicity, and pathway modulation were assessed through Western blotting, colony-formation assays, and reverse-phase protein array (RPPA) profiling. Results: We observed that co-targeting IDH2 and the UPS produced strong synergistic cytotoxicity in multiple breast cancer models, including in triple-negative MDA-MB-231 and 4T1 cells (Bliss > 25). Combination treatments led to pronounced apoptosis, evidenced by cleaved PARP-1 and Caspase-3 cleavage, and a marked loss of clonogenic potential. RPPA analysis revealed significant alterations in key survival and stress-response pathways, including NF-κB, PI3K-p85, Src, and p38-MAPK. Conclusions: Inhibition of IDH2 markedly enhances the cytotoxic effects of proteasome-targeting by disrupting metabolic–proteostatic balance and promoting apoptotic cell death. These findings identify a growth-inhibitory effect that may be leveraged to improve functional dependency in breast cancer, particularly in triple-negative breast cancer, which currently lacks efficient drug treatments. Full article

Disulfiram (DSF) is a well-established inhibitor of aldehyde dehydrogenases (ALDHs) and an FDA-approved drug for chronic alcoholism. DSF has gained attention as a versatile scaffold for drug repurposing. Its metabolite, diethyldithiocarbamate (DDTC), mediates multiple biological effects via metal chelation and covalent modification of key cysteine residues. Beyond its established anticancer properties, DSF modulates cancer stem cells, reactive oxygen species, proteasome function, and drug-resistance pathways. It also shows promise in metabolic disorders, including type 2 diabetes and obesity, by targeting enzymes such as fructose-1,6-bisphosphatase and α-glucosidase, and influences energy expenditure and autophagy. DSF exhibits antimicrobial and antiparasitic activity, enhances antibiotic efficacy against multidrug-resistant bacteria, and demonstrates antischistosomal and anti-Trichomonas effects, while also providing radioprotective benefits. The clinical translation of DSF is limited by poor solubility, rapid metabolism, and off-target effects; consequently, the development of DSF analogs has become a major focus. Structural optimization has yielded derivatives with improved selectivity, stability, solubility, and target specificity, enabling precise modulation of key enzymes while reducing adverse effects. A key structure-based strategy involves introducing bulkier substituents to exploit differences in ALDH active-site architecture and achieve target selectivity. This concept is exemplified by compounds (1) and (2), in which bulky substituents confer selective inhibition of ALDH1A1 while sparing ALDH2. This review provides a comprehensive overview of DSF analogs, their molecular mechanisms, and therapeutic potential, highlighting their promise as multifunctional agents for cancer, metabolic disorders, infectious diseases, and radioprotection. Full article

Identifying probiotics that modulate the gut–brain axis is vital for non-pharmacological Alzheimer’s disease (AD) therapy. Through a staged screening from transgenic Drosophila to a D-galactose/AlCl₃-induced murine model, Lactobacillus acidophilus LA4 and Lacticaseibacillus paracasei F5 were prioritized for their ability to improve climbing indices and reduce Aβ deposition and AChE activity. In AD mice, LA4 and F5 significantly ameliorated cognitive deficits and anxiety-like behaviors. Mechanistically, both strains reduced hippocampal Aβ_1–42 and p-Tau levels, inhibited AChE, suppressed pro-inflammatory cytokines (TNF-α, IL-6, IL-1β), and enhanced antioxidant enzymes (SOD, GSH-Px). 16S rRNA analysis revealed restored Firmicutes/Bacteroidetes ratios and enrichment of SCFA-producers (Muribaculaceae, Dubosiella). Metabolomics highlighted remodeled purine and arginine pathways, with strain-specific effects on primary bile acid biosynthesis/sphingolipid metabolism (LA4) and butanoate metabolism/nicotinate and nicotinamide metabolism (F5). Consequently, LA4 and F5 alleviate AD pathology by restructuring microbial and metabolic profiles, thereby mitigating neuroinflammation and oxidative stress. These findings confirm the potential of specific probiotics as functional food ingredients for the prevention and adjuvant treatment of neurodegenerative diseases. Full article