Search Results (327)

Extremophilic microorganisms offer an untapped potential for producing unique bioactive metabolites with therapeutic applications. In the current study, bacterial isolates were obtained from samples collected from Chamalang cave located in Kohlu District, Balochistan, Pakistan. The cave-derived isolate C1 (Rhodococcus jialingiae) exhibits prominent antibacterial activity against multidrug-resistant pathogens (MDR), including Escherichia coli, Staphylococcus aureus, and Micrococcus luteus. It also demonstrates substantial antioxidant activity, with 71% and 58.39% DPPH radical scavenging. Optimization of physicochemical conditions, such as media, pH, temperature, and nitrogen and carbon sources and concentrations substantially enhanced both biomass and metabolite yields. Optimal conditions comprise specialized media, a pH of 7, a temperature of 30 °C, peptone (1.0 g/L) as the nitrogen source, and glucose (0.5 g/L) as the carbon source. HPLC and QTOF-MS analyses uncovered numerous metabolites, including a phenolic compound, 2-[(E)-3-hydroxy-3-(4-methoxyphenyl) prop-2-enoyl]-4-methoxyphenolate, Streptolactam C, Puromycin, and a putative aromatic polyketide highlighting the C1 isolate chemical. Remarkably, one compound (C₁₄H₃₆N₇) demonstrated a special molecular profile, signifying structural novelty and warranting further characterization by techniques such as ¹H and ¹³C NMR. These findings highlight the biotechnological capacity of the C1 isolate as a source of novel antimicrobials and antioxidants, linking environmental adaptation to metabolic potential and supporting natural product discovery pipelines against antibiotic resistance. Full article

Marine algae offer environmentally friendly platforms for green nanoparticle synthesis. This study reports the biosynthesis of silver nanoparticles using polysaccharides isolated from the brown alga Chnoospora minima (PAgNPs) and evaluates their therapeutic potential. Fourier Transform Infrared Spectroscopy (FTIR) confirmed algal polysaccharide functional groups. Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX) analysis characterized the nanoparticles as spherical (~84 nm average size), stable (zeta potential −18.5 mV), and containing elemental silver without nitrogen. The PAgNPs exhibited potent antioxidant activity (~100% DPPH scavenging) and significant antimicrobial efficacy, particularly against Staphylococcus aureus and Candida species. Crucially, PAgNPs displayed potent antiproliferative activity against human lung cancer cells (A549, IC₅₀: 13.59 µg/mL). In contrast, toxicity to normal Vero cells was significantly lower (IC₅₀: 300.2 µg/mL), demonstrating notable cancer cell selectivity (SI 22.1). Moderate activity was observed against MCF-7 breast cancer cells (IC₅₀: 100.7 µg/mL). These results demonstrate that C. minima polysaccharide facilitates the synthesis of biocompatible AgNPs with promising antimicrobial and selective anticancer capabilities, highlighting their potential for further development as nanotherapeutics. Full article

Background: Natural products play a crucial role in cancer treatment due to their ability to selectively target cancer cells. Andrographolide, a major constituent of Andrographis paniculata, exhibits potential anticancer properties. Considering the pharmacological importance of nitrogen-based heteroaromatic scaffolds, particularly pyrazole motifs, this study aimed to integrate the pyrazole pharmacophore with the andrographolide scaffold to develop novel therapeutic candidates. Methods: Twenty novel 3,19-(N-phenyl-3-aryl-pyrazole) acetals of andrographolide and isoandrographolide were synthesized and characterized using UV-Vis, FT-IR, NMR, and HRMS. Initial anticancer screening was conducted by the National Cancer Institute (NCI), USA, against 60 human cancer cell lines. The most promising compound, 1f (R = 4-F), was selected for further biological evaluation in the MDA-MB-231 breast cancer cell line. Results: The MTT assay results demonstrated that compound 1f exhibited strong, dose-dependent anti-proliferative effects. The apoptosis analysis of 1f revealed a time-dependent increase in apoptotic cells, and cell cycle studies indicated S phase arrest in MDA-MB-231 cells. Antioxidant activity via the DPPH assay identified compounds 1b (R = 3-NO₂) and 2b (R = 3-NO₂) as the most effective radical scavengers. The most active compounds were also evaluated for drug-likeness using in silico Lipinski’s rule assessments. Conclusions: The synthesized 3,19-(N-phenyl-3-aryl-pyrazole) acetals of andrographolide and isoandrographolide exhibited promising anticancer and antioxidant properties. Among them, compound 1f showed the most significant activity, supporting its potential as a lead candidate for further anticancer drug development. Full article

Melatonin (MEL)is an endogenous hormone with antioxidant potential that plays an important role in maintaining redox homeostasis. MEL and its derivatives directly scavenge free oxygen and nitrogen radicals. Melatonin inhibits lipid peroxidation, stimulates antioxidant enzymes, and reduces metal toxicity. It stabilizes mitochondrial activity and suppresses inflammatory signaling. It takes part in neurogenesis, neuroprotection, and modulation of the cardiovascular system. It prevents many diseases of free radical etiology, i.e., neurodegenerative and circulatory system diseases and ischemic stroke. Supplementation with this antioxidant can slow down the aging process and provide protection against diseases of the central nervous system and support the body’s natural antioxidant system. This study uses current reports from the literature and meta-analyses of the antioxidant mechanisms of melatonin and its importance in neurodegenerative diseases. Full article

Betalains are nitrogen-containing, water-soluble, and non-toxic natural pigments found in various plant species. Among these, Celosia argentea (Amaranthaceae) has garnered attention as a significant source, accumulating substantial quantities of both red–purple betacyanins and yellow–orange betaxanthins. Impressively, betalain concentrations in C. argentea inflorescences can reach up to 14.91 mg/g dry weight (DW), a level comparable to that reported in red beetroot. Beyond harvesting from inflorescences, betalains can also be produced using cell culture systems, which can yield even higher amounts, up to 42.08 mg/g DW. Beyond their role as vibrant natural colorants, betalains exhibit impressive health-promoting properties, most notably potent antioxidant activities. For instance, C. argentea inflorescence extracts demonstrate approximately 84.07% 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 88.70% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. Extracts derived from cell cultures show even higher scavenging capacities, reaching up to 99.28% for ABTS and 99.63% for DPPH, rivaling the antioxidant standard (ascorbic acid). Further research indicates additional potential benefits, including anti-inflammatory, antimicrobial, anticancer, antidiabetic, and hepatoprotective properties. This diverse bioactivity underpins their value across various industries. Betalains serve as natural colorants and functional ingredients in food and beverages, offer sustainable alternatives for textile dyeing, and hold therapeutic promise in cosmetics and pharmaceuticals. This review critically examines existing research on betalain production in C. argentea. Recognizing that research specific to C. argentea is less extensive compared with that on species such as Beta vulgaris and Hylocereus polyrhizus, this review analyzes its biosynthetic pathways, diverse biological properties, and wide-ranging applications. This is achieved by integrating available C. argentea-specific data with relevant insights drawn from these more broadly studied betalain sources. Furthermore, the review discusses perspectives on future research directions aimed at optimizing yield and exploring the full potential of betalains, specifically within C. argentea. Full article

Apple (Malus domestica Borkh.) is an economically important fruit. The use of nitrate by plants plays a crucial role in their growth and development, and its absorption and dispersal are controlled by nitrate transport proteins (NRTs). In this study, we investigated the potential function of MdNRT2.4 under low-nitrogen (N) stress by overexpressing it in tobacco. Compared with plants treated with a normal nitrogen level (5 mM), the MdNRT2.4 overexpression lines under low-N stress (0.25 mM) exhibited significantly greater plant height and width, as well as larger leaves and a higher leaf density, than wild-type plants, suggesting that the overexpression of MdNRT2.4 enhances the low-N tolerance of tobacco. Enhanced antioxidant enzyme activities in the MdNRT2.4 overexpression plant lines promoted the scavenging of reactive oxygen species, which reduced damage to their cell membranes. GUS staining of pMdNRT2.4::GUS-transformed Arabidopsis thaliana lines showed that MdNRT2.4 was expressed in the roots, vascular bundles, seeds in fruit pods, and young anther sites, suggesting that MdNRT2.4 mediates the transport of nitrate to these tissues, indicating that MdNRT2.4 might promote nitrate utilization in apple and improve its tolerance to low-N stress. Experiments using yeast one-hybrid and dual-luciferase assays revealed that MdbHLH3 binds to the MdNRT2.4 promoter and activates its expression. MdbHLH3 belongs to the basic helix–loop–helix (bHLH) transcription factor (TF). It is speculated that MdbHLH3 may interact with the promoter of MdNRT2.4 to regulate N metabolism in plants and enhance their low-N tolerance. This study establishes a theoretical framework for investigating the regulatory mechanisms of low-N responsive molecules in apple, while simultaneously providing valuable genetic resources for molecular breeding programs targeting low-N tolerance. Full article

Background: Natural astaxanthin, a commercially valuable carotenoid, is primarily sourced from Haematococcus pluvialis, a microalga known for its remarkable resilience to environmental stress. Methods: In this study, the physiological and transcriptomic responses of H. pluvialis to ND were investigated at various time points under high light conditions. Results: Under high light conditions, nitrogen deprivation (ND) enhances astaxanthin content (33.23 mg g⁻¹) while inhibiting the formation of the secondary cell wall (SCW), increasing astaxanthin content by 29% compared to the nitrogen-replete group (25.64 mg g⁻¹); however, the underlying mechanisms remain unclear. ND reduced chlorophyll fluorescence parameters, elevated reactive oxygen species (ROS) levels, and increased starch and total sugar accumulation while decreasing protein and lipid content. Fatty acid content increased on the first day but had declined by the fifth day. A transcriptomic analysis revealed substantial alterations in gene expression in response to ND. Genes associated with the TCA cycle, glycolysis, astaxanthin biosynthesis, and cell motility were upregulated, while those involved in photosynthesis, lipid synthesis, ribosome biogenesis, amino acid synthesis, and SCW synthesis were downregulated. Additionally, ND modulated the expression of genes involved in ROS scavenging. Conclusions: These findings provide critical insights into the adaptive mechanisms of H. pluvialis in response to ND under high light, contributing to the development of strategies for enhanced production of astaxanthin-rich motile cells. Full article

In this research, an emerging, non-metallic photocatalyst was prepared by the thermal polymerization method from three different precursors: urea, melamine, and three mixtures of melamine and cyanuric acid. Graphitic carbon nitride (g-C₃N₄) samples from urea and melamine were synthesized in a muffle furnace at three different temperatures: 450°, 500°, and 550 °C for 2 h, while the samples made of a mixture of melamine and cyanuric acid (with mass ratios of 1:1, 1:2, and 2:1) were synthesized at 550 °C for 2 h. All the samples were characterized in order to determine their chemical and physical properties, such as crystallite size and structure, and phase composition by the following techniques: Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). Nitrogen adsorption/desorption isotherms were used to investigate the Brunauer, Emmett, and Teller (BET) specific surface area and Barrett–Joyner–Halenda (BJH) pore size distribution. Band gap values were determined by diffuse reflectance spectroscopy (DRS). Furthermore, adsorption and photocatalytic degradation of the local anesthetic drug procaine were monitored under UV-A, visible, and simulated solar irradiation in a batch reactor. Kinetic parameters, as well as photocatalytic mechanisms using scavengers, were determined and analyzed. The results of the photocatalysis experiments were compared to the benchmark TiO₂ Evonik Aeroxide P25. The results indicated that the g-C₃N₄ sample synthesized from urea at 500 °C for 2 h exhibited the highest degradation rate of procaine under visible light. Full article

Influenza A virus (IAV) is an important respiratory pathogen. We evaluated the IAV-inactivation activity of hydroxytyrosol (HT)-rich aqueous olive pulp extract (HIDROX^®) and its mechanisms. The HIDROX-containing solution and cream showed concentration- and time-dependent virucidal activity. The virucidal activity of HIDROX was higher than pure HT. With Western blotting (WB), the band intensities of multiple viral structural proteins in HIDROX- and HT-treated viruses were weaker than in the control, and high-molecular-mass bands were observed. These results suggest that HIDROX and HT may have induced the structural changes or abnormalities of viral proteins. HIDROX and HT had no or limited impact on hemagglutination and neuraminidase activities, as well as the virus genome. No apparent abnormalities in the viral particles were observed through electron microscopy following treatment with HIDROX and HT. Treatment with HT, but not HIDROX, resulted in the production of high levels of reactive oxygen species (ROS) and/or reactive nitrogen species (RNS). In HT treatment but not HIDROX treatment, the virucidal activity disappeared, and the induction of abnormal band patterns of a viral protein in WB was cancelled by ROS/RNS scavenger activity. These findings showed the possible utility of HIDROX as a naturally derived IAV virucidal component that may contribute to IAV control. Full article

This study employs a plasma-coupled calcium peroxide (CaO₂) system to degrade tetracycline (TC) and remove phosphorus from emergency wastewater in a chemical industry park. The plasma/CaO₂ system achieves optimal performance when the CaO₂ dosage reaches 0.13 g/L. Higher degradation efficiencies of TC were observed at increased discharge voltages, frequencies, and under weakly acidic and weakly alkaline conditions. Variations in discharge voltage and frequency have no significant impact on the phosphorus removal efficiency, but weakly alkaline conditions favor phosphorus removal. The reactive species (·OH, ¹O₂, O₂·⁻) within the plasma/CaO₂ system were identified, and their roles were elucidated using radical scavengers. Subsequently, the degradation process was characterized by measuring changes in total organic carbon (TOC), chemical oxygen demand (COD), and ammonia nitrogen during the reaction, along with three-dimensional fluorescence analysis and ultraviolet-visible spectroscopy (UV-Vis). Eight intermediate products were identified through LC-MS, and two degradation pathways were clarified based on density functional theory. The toxicity analysis of the intermediate products demonstrated that the plasma/CaO₂ system is an efficient, feasible, and environmentally friendly method for the synchronous removal of organic pollutants and phosphorus from emergency wastewater in a chemical industry park. Full article

Cold stress critically restricts maize seedling growth in Northeast China, yet the mechanism by which cold priming (CP) enhances cold tolerance through proline–nitrogen metabolic networks remains unclear. This study systematically investigated CP’s synergistic regulation in cold-tolerant (Heyu27) and cold-sensitive (Dunyu213) maize using a two-phase temperature regime (priming induction/stress response) with physiological and multivariate analyses. CP alleviated cold-induced photosynthetic inhibition while maintaining a higher chlorophyll and photosynthetic rate, though biomass responses showed varietal specificity, with Heyu27 minimizing growth loss through optimized carbon–nitrogen allocation. Antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were pre-activated during early stress, effectively scavenging reactive oxygen species (ROS) and reducing malondialdehyde (MDA) accumulation, with Heyu27 showing superior redox homeostasis. CP enhanced proline accumulation via bidirectional enzyme regulation (upregulating ∆¹-pyrroline-5-carboxylate synthase/reductase [P5CS/P5CR], inhibiting proline dehydrogenase [ProDH]) and reprogrammed nitrogen metabolism through glutamate dehydrogenase/isocitrate dehydrogenase (GDH/ICDH)-mediated ammonium conversion to glutamate, alleviating nitrogen dysregulation while supplying proline precursors. Principal component analysis revealed divergent strategies: Heyu27 prioritized proline–antioxidant synergy, whereas Dunyu213 emphasized photosynthetic adjustments. These findings demonstrate that CP establishes “metabolic memory” through optimized proline–nitrogen coordination, synergistically enhancing osmoregulation, reactive oxygen species (ROS) scavenging, and nitrogen utilization. This study elucidates C₄-specific cold adaptation mechanisms, advancing cold-resistant breeding and stress-resilient agronomy. Full article

Four different-sized carbon microspheres, CS, obtained by a facile hydrothermal method, are applied as a hard template for the preparation of a series of macroporous LaFeO₃. The average particle size of the CS obtained is between 0.350 and 0.700 µm. The macroporous LaFeO₃ are tested in a Fenton-like activation of peroxymonosulfate, PMS, for oxidation of tetracycline hydrochloride, TCH, in model water solution under visible-light irradiation. The effect of parameters such as type of irradiation, temperature of the reaction, and type of the water matrixes was tested. The oxidation of the pollutant TCH is evaluated by total organic carbon and organic nitrogen measurements. The results showed the superior catalytic activity of macroporous LaFeO₃ in comparison to pure LaFeO₃. Rate constants between 0.036 and 0.184 min⁻¹ at 25 °C were obtained. The activation energy for the process with the most active macroporous LaFeO₃ was 33.88 kJ/mol, a value lower than for the catalytic process with PMS only, proving the positive role of the macroporous LaFeO₃ for TCH degradation. Radical scavenger measurements showed that singlet oxygen, produced during the catalytic degradation process, was responsible for the performance of macroporous LaFeO₃/PMS/visible light for TCH degradation. The catalysts proved to be efficient and recyclable. Full article

This study presents a comprehensive kinetic analysis of sulfamethoxazole (SMX) degradation by the photo-Fenton process, highlighting its potential for removing emerging micropollutants in water treatment. The degradation of SMX followed pseudo-first-order kinetics, with increasing Fe(II) concentrations significantly accelerating the oxidation rate. A kinetic model was developed to describe SMX removal, aromaticity loss, and color changes during treatment. Although SMX was rapidly eliminated, intermediate aromatic and chromophoric compounds persisted, requiring extended reaction times for complete mineralization. The kinetic modeling of aromaticity and color revealed distinct degradation pathways and rate constants, showing a strong dependence on iron dosage. The formation of nitrate and sulfate was used to monitor nitrogen and sulfur mineralization, respectively. Optimal nitrate formation was achieved at 22 mol SMX: 1 mol Fe(II), beyond which excessive iron promoted radical scavenging and the formation of stable Fe–aminophenol complexes, inhibiting complete nitrogen oxidation and aromatic degradation. Moreover, excessive Fe(II) led to increased water coloration due to complexation with partially oxidized aromatic byproducts. These findings emphasize the need for optimized catalyst dosing to balance degradation efficiency and minimize secondary effects. The proposed kinetic models offer a predictive tool for improving photo-Fenton-based treatments and integrating them with biological processes to enhance micropollutant bioremediation. Full article

Background: Sucralose and benzo(a)pyrene (B[a]P) are widespread foodborne substances known to harm human health. However, the effects of their combined exposure on kidney function remain unclear. This study aimed to investigate the mechanisms by which sucralose and B[a]P induce kidney injury through P-glycoprotein (PGP/ABCB1), a crucial protein involved in cellular detoxification. Methods: C57BL/6N mice were co-treated with sucralose and B[a]P for 90 days to evaluate their impact on kidney histopathology and function. In vitro experiments assessed cell viability, reactive oxygen species (ROS) levels, and B[a]P accumulation by flow cytometry. Molecular docking and cellular thermal shift assay (CETSA) were used to determine the binding affinity of sucralose to PGP. Furthermore, PCR, Western blotting, and immunohistochemistry were performed to analyze the expression of PGP and its upstream transcription factors. Results: Ninety days of co-exposure to sucralose and B[a]P significantly exacerbated renal dysfunction in mice, as evidenced by the elevated level of serum creatinine and urea nitrogen, which could be reverted by ROS scavenger N-acetyl cysteine (NAC). In vitro, sucralose promoted cellular accumulation of B[a]P, consequently enhancing B[a]P-induced cell growth inhibition and ROS production. Consistently, B[a]P accumulation was enhanced by PGP knockdown in both HK2 and HEK-293 cells. Mechanistically, sucralose can directly bind to PGP, competitively inhibiting its efflux capacity and increasing intracellular B[a]P retention. Prolonged co-exposure further downregulated PGP expression, possibly through the reductions of its transcriptional regulators (PXR, NRF2, and NF-κB). Conclusions: Co-exposure to sucralose and B[a]P exacerbates renal injury by impairing PGP function. Mechanistically, sucralose inhibits PGP activity, resulting in the accumulation of B[a]P within renal cells. This accumulation triggers oxidative stress and inhibits cell growth, which demonstrates that sucralose potentiates B[a]P-induced nephrotoxicity by directly inhibiting PGP-mediated detoxification pathways, thus underscoring the critical need to evaluate toxicity risks associated with combined exposure to these compounds. Full article

This study evaluated the effect of cold plasma (CP) on the physicochemical properties and antioxidant capacity of maize. CP treatments were performed using a glow discharge, applying argon and/or nitrogen at 50 W, with different working pressures (75, 100, and 125 Pa) and exposure times (1, 5, and 10 min). The maize samples were analyzed before and after treatments for color, fatty acid value (FAV), malondialdehyde content, superoxide dismutase and catalase activities, total phenol content (TPC), ascorbic acid content, reduced glutathione content, and antioxidant activity. The antioxidant activity was further evaluated during storage (25 °C for 180 days). After treatments, color parameters (brightness, yellowness, and saturation) showed measurable enhancement, while FAV and malondialdehyde content were significantly reduced by 14.95–56.37% and 11.38–43.71%, respectively. The optimal treatment conditions (100 Pa working pressure and 5 min exposure) maximized antioxidant enzyme activities and bioactive compound levels, accompanied by substantial increases in TPC. Under these conditions, maize samples had the highest organic radical scavenging capacities (DPPH), reaching 1.31-fold (argon plasma) and 1.25-fold (nitrogen plasma) that of untreated sample. During storage, all samples subjected to the optimal combined treatment exhibited higher DPPH radical scavenging capacity and ferric reducing antioxidant potential, along with lower FAVs and malondialdehyde contents compared to the untreated sample. Additionally, the DPPH radical scavenging capacity exhibited statistically inverse correlations with both FAV (r² = −0.49) and malondialdehyde content (r² = −0.15), as quantified through Pearson correlation analysis. These findings indicated that glow discharge cold plasma is a potentially effective non-thermal processing technique to enhance bioactive compound accumulation and antioxidant enzyme activity for preserving maize’s physicochemical properties, with possible use in the food industry for sustainable grain preservation strategies, particularly in delaying oxidative deterioration. Full article