Search Results (4,563)

This study investigated the effects of regulated deficit irrigation on quality and postharvest characteristics of ‘Soreli’ kiwifruit (Actinidia chinensis Planch.). Plants were irrigated at 100% (control), 80%, and 60% of the standard water supply. Fruit quality was monitored by assessing weight loss (WL), firmness, soluble solids content (SSC), and color stability. Bioactive compounds, such as polyphenols (POL), flavonoids (FLAV), ascorbic acid (AA), β-carotene (Car), and chlorophyll (Chl) content and antioxidant enzyme activities, including ascorbate peroxidase (APX), superoxide dismutase (SOD), and catalase (CAT), and the 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay were also evaluated. Results indicated that reduced irrigation at 60% of water supply enhanced antioxidant enzyme levels, without negatively affecting fruit quality parameters: greater resistance to firmness loss, higher soluble solids accumulation, and better color stability. In the early stages of cold storage, fruits under the 60% irrigation treatment showed higher POL, FLAV, and ABTS values, with polyphenols exceeding 200 mg GAE 100 g⁻¹ FW and FLAV content ranging from 4.69 to 5.53 mg CE 100 g⁻¹ FW. The 80% irrigation treatment showed a moderate biochemical response without altering quality. Controlled water deficit can enhance antioxidant activity and bioactive compounds, improving fruit quality and the environmental and commercial value of ‘Soreli’ kiwifruit. Full article

Rapid detection of β-lactamase activity is becoming increasingly important as β-lactam resistance spreads at an alarming rate and conventional diagnostics often require several hours to deliver actionable results. Over the past decade, methods based on luminescence, bioluminescence, chemiluminescence, and fluorescence have become powerful tools for the functional assessment of resistance resulting from β-lactamase activity. These approaches provide highly sensitive, activity-based readouts, often within minutes, and frequently rely on simple optical instrumentation. In this review, we summarize recent developments in luminescent probe design between 2015 and 2025, with emphasis on reaction mechanisms, analytical performance, and the ability of these systems to discriminate between different β-lactamases, including narrow-spectrum enzymes, AmpC, ESBL, and carbapenemases. We also discuss their applications in bacterial cultures, clinical isolates, complex biological matrices and, in some cases, in vivo models. While luminescent assays are not yet positioned to replace standard susceptibility testing, they offer a practical and increasingly robust complement to culture-based and molecular methods. The emerging trends highlighted here, such as self-immobilizing fluorogenic probes, chemiluminescent relay systems, nanomaterial-based sensors and AI-assisted mobile platforms, suggest that luminescent β-lactamase detection could play a meaningful role in future rapid diagnostics and resistance surveillance. Full article

Obtaining enzymes through bioconversion depends on a complex relationship between the microorganisms and the biomass used. Here, we evaluate xylanase production by diverse actinobacterial species, cultivated using xylan as the sole carbon source and complex media containing sorghum as the substrate. Fifty-three actinobacteria were tested for xylanase production in a solid medium. Seventeen strains produced xylanase and were tested for their ability to produce xylanase, total cellulases (filter paper activity, FPase), and endoglycanase in submerged culture using a defined liquid medium. The best xylanase-producing species was Streptomyces capoamus, yielding 24 IU·mL⁻¹. For FPase, Streptomyces sp. showed the highest yield (1.12 IU·mL⁻¹); for endoglycanase, the best producer was Streptomyces ossamyceticus (0.99 IU·mL⁻¹). When sweet sorghum was used alone, S. curacoi, S. ossamyceticus, and S. capoamus showed xylanase activities of 4.5 IU·mL⁻¹, 4.4 IU·mL⁻¹, and 0.8 IU·mL⁻¹, respectively. However, FPase activity was not detected under the assay conditions. The results showed that there is an intraspecific difference in xylanase, endoglucanase, and FPase production by actinobacteria, with the species S. curacoi, S. ossamyceticus, and S. capoamus able to use sorghum as a carbon source, demonstrating biotechnological potential. Full article

In this study, a silver-based metal–organic framework (Ag-MOF) nanozyme was synthesized for the synergistic eradication of drug-resistant Salmonella enteritidis in food matrices. Ag-MOF exhibits multiple enzyme-like activities, namely oxidase (OXD)-, peroxidase (POD)-, and superoxide dismutase (SOD)-like activities. It demonstrated excellent antibacterial and antibiofilm activities against erythromycin- and chloramphenicol-resistant S. enteritidis strains (N29 and P23). Specifically, treatment with 20 mg mL⁻¹ Ag-MOF resulted in nearly complete eradication of S. enteritidis in in vitro suspension assays, including 1 × 10⁷ CFU mL⁻¹ N29 strain and 6 × 10⁶ CFU mL⁻¹ P23 strain. Moreover, treatment with 1 mg mL⁻¹ Ag-MOF led to 80~90% biofilm inhibition of S. enteritidis. Mechanistic investigations revealed that Ag-MOF effectively interacted with amino-rich structures on the bacterial surface (such as membrane proteins and peptidoglycan components), generated abundant reactive oxygen species (ROS), released Ag⁺ ions, and depleted intracellular glutathione, which collectively disrupted cell membrane integrity and induced severe leakage of intracellular proteins and nucleic acids. Importantly, Ag-MOF maintained high antibacterial efficacy in complex simulated food matrices (pork, milk, and egg shell). Overall, this study offers key insights into enzyme-mimicking antibacterial materials and a promising strategy to combat multidrug resistant foodborne pathogens. Full article

Sunlight exposure contributes to human health; however, excessive light exposure to skin, especially ultraviolet B (UV-B), can produce high amounts of reactive oxygen species (ROS) and induce inflammation. Some antioxidants, such as squalene, can prevent UV-B-induced inflammation. C₃₄H₅₈ botryococcene is the most common triterpene hydrocarbon produced by green alga Botryococcus braunii; it is biosynthesized via a pathway similar to squalene and appears to have a similar chemical structure to squalene. However, there are no reports on the bioactivity of botryococcene. In this study, we evaluated that botryococcene can prevent the skin photoaging. Using ESR assay, botryococcene could not scavenge any ROS. However, treatment of epidermis cells with the botryococcene significantly suppressed intracellular ROS production by hydrogen peroxide (H₂O₂) and attenuated H₂O₂ cytotoxicity. Botryococcene enhanced the antioxidant enzymes in gastric cells, thus botryococcene may scavenge ROS indirectly, not directly. Moreover, botryococcene inhibited production of intracellular interleukin-1 and exhibited suppression of melanogenesis activity by UV-B irradiation. Addition of botryococcene-treated epidermal cells culture medium mitigated the increase in matrix metalloproteinase-1 production and the decrease in type I collagen production induced by UV-B irradiation in dermis cells. These results showed that botryococcene has anti-photoaging effects, including preventing wrinkles and blemishes on the skin. Full article

Lipopolysaccharides (LPSs) are potent pro-inflammatory neurotoxins abundant in the gut microbiome and originate primarily from Gram-negative bacteria, such as Escherichia coli. LPS levels increase with brain aging and accumulate around neurons in Alzheimer’s disease (AD) brains. Microbiome-generated LPS and other endotoxins cross gut barriers, enter systemic circulation, and translocate across the blood–brain barrier into vascularized brain regions. These processes are exacerbated by aging and neurovascular diseases. Although pro-homeostatic systems mitigate LPS effects, these defenses can fail. This study provides the first evidence that acyloxyacyl hydrolase (AOAH; EC 3.1.1.77), a microglia-enriched LPS detoxifying enzyme, shows reduced expression in AD brain tissue. Analysis of AD patient brains revealed reduced AOAH messenger RNA (mRNA) levels, accompanied by elevated expression of microRNA (hsa-miR-450b-5p), an inflammation regulator. Furthermore, luciferase reporter assays demonstrated that miR-450b-5p specifically targets the AOAH 3′-UTR, leading to a dose-dependent suppression of reporter activity. Also, in vitro experiments on human neuronal glial (HNG) cells further confirmed down-regulation of AOAH expression at protein levels by miR-450b-5p. These findings suggest miR-450b-5p-mediated AOAH deficiency drives LPS-associated neurotoxicity and inflammatory neurodegeneration in AD. Full article

Background/Objectives: Intestinal α-glucosidases, including maltase, sucrase, and trehalase, are key enzymes responsible for the final steps of carbohydrate digestion. Although Thai medicinal plants possess diverse bioactivities, most previous studies on plant-derived α-glucosidase inhibitors have focused on single-enzyme assays, primarily maltase, and lack systematic comparison of the three major intestinal disaccharidases—maltase, sucrase, and trehalase. This study aimed to determine the kinetic properties of rat intestinal α-glucosidases and evaluate the inhibitory potential of selected Thai plant extracts. Methods: Rat small-intestinal S9 fractions, post-mitochondrial supernatant obtained by centrifugation at 9000× g, containing soluble enzymes and microsomal components responsible for disaccharidase activity, were prepared and disaccharidase activities were quantified using the glucose oxidase–peroxidase method. Kinetic parameters were obtained from Eadie–Hofstee plots using maltose, sucrose, and trehalose as substrates. Fourteen Thai plant extracts (Oryza sativa, Cratoxylum formosum, Garcinia cawa, Aganosma marginata, Polyalthia evecta, Ellipeiopsis cherrevensis, Ancistrocladus tectorius, Micromelum minutum, and Microcos tomentosa) and isolated compounds (Bergapten, Eurycomalactone, Lupinifolin, Osthole) were assessed at 100 and 250 µg/mL for inhibition of maltase, sucrase, and trehalase. Results: Maltase exhibited the highest substrate affinity based on the lowest Km value. Among the tested samples, the 80% ethanol extract of Microcos tomentosa (MT80) inhibited maltase, sucrase, and trehalase activities by approximately 10–60% at 250 µg/mL, and was the only extract showing consistent inhibition across all three enzymes. Other extracts showed selective inhibition toward one or two enzymes. Conclusions: These findings indicate that MT80 possesses a broad-spectrum inhibitory profile against major intestinal α-glucosidases, suggesting a potential advantage for comprehensive regulation of postprandial glucose excursions and supporting its candidacy as a source of novel α-glucosidase inhibitors. Full article

Cadmium (Cd) is a toxic heavy metal that impairs plant growth and induces oxidative stress. In this study, we compared the physiological, biochemical, and molecular responses of two durum wheat (Triticum turgidum ssp. durum) cultivars, Razek and Chili, to Cd stress. Seedlings were exposed to 0, 5, and 50 µM Cd (Cd²⁺; supplied as CdCl₂) under controlled hydroponic and Petri assay conditions. Cd reduced radicle elongation, biomass accumulation, and water uptake in both cultivars, but the relative inhibition of growth was lower in Razek than in Chili, indicating a better capacity to maintain growth under Cd stress. This was accompanied by milder oxidative stress symptoms and more stable antioxidant enzyme activity, particularly for catalase (CAT) and ascorbate peroxidase (APX). Gene expression analyses revealed that Razek maintained a higher expression of antioxidant and stress-related genes under acute Cd stress, while Chili exhibited pronounced downregulation. Histochemical analyses showed increased H₂O₂ accumulation and lignin deposition in Chili roots, suggesting a stronger stress response. Notably, Chili also showed a sharp depletion of reduced glutathione (GSH) under high Cd concentrations, with limited upregulation of GSH synthesis and phytochelatin-related genes. Together, these findings indicate that Razek activates more efficient detoxification, redox regulation, and hormonal signaling pathways under Cd stress, indicating its potential suitability for cultivation in slightly Cd-contaminated soils. Full article

Fish is highly prone to spoilage due to a combination of intrinsic biochemical processes and microbial proliferation, which together drive rapid quality deterioration during post-harvest handling and storage. These processes are further accelerated by factors such as elevated temperatures, mechanical damage, and suboptimal handling. In Mediterranean aquaculture, ice slurry is the standard harvesting method. This study aimed to characterize the initial post-harvest enzymatic activity of key proteolytic enzymes, calpain, collagenase, cathepsin B (CTSB), and cathepsin L (CTSL), in the white muscle of three commercially important species (Sparus aurata, Dicentrarchus labrax, and Pagrus major) harvested under standard practices across three seawater harvest temperatures (low, medium, and high). Muscle samples were collected over a 13-day chilled storage period post-harvest, and enzymatic activity was assessed using standardized fluorometric assays. Our findings establish the basal post-mortem proteolytic profiles for each species and reveal marked species-specific differences in enzyme activity patterns. Calpain and collagenase exhibited early and parallel activation, while CTSB and CTSL showed a coordinated increase during storage. Harvest temperature emerged as a critical factor, with the highest enzymatic activities consistently observed during the moderate temperature period. These results underscore the importance of species-specific physiology and seasonal conditions in shaping post-harvest filet degradation, offering a basis for refining harvest strategies to enhance quality management in Mediterranean aquaculture. Full article

In this study, a Nocardia niigatensis strain was isolated from boron-rich mining soils in the Bigadiç region of Türkiye and comprehensively characterized. The primary aim of this study was to isolate boron-tolerant Nocardia species and evaluate their physiological, enzymatic, and biochemical profiles. Selective isolation techniques were employed to obtain Nocardia isolates, and species-level identification was achieved using both 16S rRNA gene sequencing and MALDI-TOF MS analysis, which consistently confirmed the isolate as N. niigatensis. In addition to molecular identification, the morphological, physiological, and biochemical characteristics of the strain were extensively investigated. The strain demonstrated notable boron tolerance, exhibiting robust growth at concentrations up to 50 mM, highlighting its potential applicability in the bioremediation of boron-contaminated environments. Physiological assays further revealed moderate halotolerance and a mesophilic growth profile, with optimal growth observed at 27–37 °C. Enzymatic screening indicated positive L-glutaminase activity, an enzyme of considerable industrial relevance. Moreover, API ZYM profiling revealed a broad enzymatic spectrum, including esterases, arylamidases, phosphatases, and glucosidases, suggesting substantial metabolic versatility. Antibiotic susceptibility testing showed sensitivity to doxycycline, tobramycin, and erythromycin, whereas resistance was observed against imipenem and several β-lactam antibiotics. Metagenomic analysis of boron-rich soils from two distinct mining sites revealed marked differences in microbial community composition, with variations in Actinobacteria abundance associated with mineral type. Overall, these findings emphasize the adaptive capacity and biotechnological potential of environmental Nocardia strains inhabiting chemically stressful ecosystems, warranting further genomic and metabolomic investigations. Full article

Neurodegenerative diseases, including Alzheimer’s disease, are marked by cholinergic dysfunction, oxidative stress, and reduced neurotrophic support, which drives the quest for multifunctional therapeutic agents. This pilot study presents four novel monoterpene–aminoadamantane conjugates (MACs 1–4) designed to combine the antioxidant and neuromodulatory characteristics of monoterpenes with the neuroprotective properties of aminoadamantane derivatives. Their physicochemical characteristics, blood–brain barrier permeability, and binding affinity to human acetylcholinesterase (AChE) were evaluated using molecular docking and in silico descriptor analysis. In vivo, the neuroprotective efficacy of the MACs was investigated in a scopolamine-induced dementia model in rats, employing behavioral tests. Biochemical assays conducted in the hippocampus and prefrontal cortex assessed AChE activity, antioxidant enzyme performance, lipid peroxidation levels, total glutathione content, and BDNF concentrations. The findings indicate that MAC1, MAC3, and MAC4 demonstrate favorable calculated blood–brain barrier permeability, strong predicted affinity for AChE, and significant in vivo alleviation of scopolamine-induced memory deficits, in conjunction with improvement of key markers of oxidative stress and cholinergic function. These results show that the structural hybridization of myrtenal with aminoadamantane frameworks produces promising multifunctional ligands that are relevant for Alzheimer’s-type neurodegeneration. Full article

Significant advances in coronavirus immunoprophylaxis have enabled the control of the SARS-CoV-2 pandemic. However, the continued emergence of SARS-CoV-2 variants with immune escape potential highlights the need for effective direct-acting antivirals targeting conserved viral enzymes. The SARS-CoV-2 main protease (M^pro) remains one of the most promising antiviral drug targets due to its essential role in viral replication and the high conservation of its active site across coronavirus variants. Building upon the established GC373 scaffold, we designed, synthesized, and biochemically evaluated two novel GC373-like peptidomimetic inhibitors incorporated modified glutamine-mimic residues. These analogs were designed to enhance solubility and metabolic resilience while retaining key recognition features within the M^pro active site. Both compounds demonstrated micromolar inhibitory activity in enzymatic assays, supported by molecular docking and MM-PBSA analyses consistent with stable binding. The proposed inhibitors represent viable scaffolds for further optimization of electrophilic warheads and S1/S2 residue interactions. These findings contribute to the rational design of next-generation M^pro inhibitors and align with ongoing efforts to expand the chemical space of SARS-CoV-2 antiviral agents. 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

Enzymes of the α-glucosidase group cleave α-D-glucose from the non-reducing end of short oligosaccharides. They contribute to carbohydrate digestion as maltase-glucoamylase in the intestinal brush border and as neutral α-glucosidase in other tissues. Neutral α-glucosidase is also active in blood, but little is known about its relevance as an indicator of the body’s metabolic state. Therefore, we proved whether the α-glucosidase activity level in blood does reflect the state of negative energy balance (NEB). As NEB commonly occurs in dairy cows around calving, our study included blood (serum, plasma) samples of 73 Holstein Friesian cows collected ±14 d to parturition. After the establishment and characterization of a fast and low-cost activity assay, these blood samples were analyzed for α-glucosidase compared to known NEB biomarkers. This analysis revealed the lowest α-glucosidase activity 5 d post partum (−25% compared to 14 d ante partum) by using two different α-glucosidase substrates. The reduced activity recovered 14 d post partum; however, the degree of recovery depended inversely on the number of parities. In this regard, α-glucosidase activity changed peripartum in line with known biomarkers (e.g., NEFA, IGF-1, glucose). In conclusion, the α-glucosidase activity is a new and easily detectable blood parameter of NEB in dairy cows. Full article

Background/Objectives: Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) represents one of the major contributors to morbidity and mortality in Rheumatoid arthritis (RA), yet its underlying molecular mechanisms remain incompletely defined. Activin A, a member of the transforming growth factor-β (TGF-β) superfamily, has emerged as a key regulator of inflammation, fibroblast activation, and tissue remodeling. However, its role in RA patients with interstitial lung disease (ILD) has not been fully elucidated. We aimed to investigate circulating levels of Activin A, Follistatin-Like Protein-1 (FSTL1), and Follistatin-Like Protein-3 (FSTL3) in patients with RA, RA-ILD, idiopathic pulmonary fibrosis (IPF), and healthy controls and explore their associations with disease activity and pulmonary function parameters. Methods: This cross-sectional study included 90 participants: healthy controls (n = 20), RA (n = 25), RA-ILD (n = 21), and IPF (n = 24). Serum biomarkers were quantified using validated enzyme-linked immunosorbent assays (ELISAs). Clinical characteristics, inflammatory markers, disease activity indices, and pulmonary function tests were recorded. Group comparisons and correlation analyses were performed using appropriate parametric and non-parametric statistical methods. Results: Circulating Activin A levels were progressively increased from controls to RA, RA-ILD, and IPF, with significantly higher concentrations in all disease groups relative to controls. FSTL1 levels were significantly reduced in RA-ILD patients compared with RA and controls, while FSTL3 levels were markedly elevated in IPF. Activin A did not correlate with disease activity indices or pulmonary function parameters, whereas FSTL1 correlated positively with diffusing capacity of the lungs for carbon monoxide and disease duration, and FSTL3 showed an inverse association with lactate dehydrogenase. Conclusions: Activin A may be associated with the fibroinflammatory burden in both RA-ILD and IPF. The observation of altered circulating levels of Follistatin-like proteins—key regulatory molecules with multifaceted biological functions—suggests that the underlying pathogenesis is complex and governed by tightly regulated, interconnected signaling pathways. Full article