Search Results (1,174)

The aim of this study was to acquire endospore-former(s) for aquatic animal feed based on the probiotic potential in vitro, including the anti-pathogen spectrum, gastrointestinal fluid tolerance, antioxidant activity, enzyme-producing ability, and basic safety assessment. The strain Bacillus velezensis FJAT-57093 was found to exhibit the strongest antibacterial ability against Aeromonas hydrophila in the agar well diffusion inhibition assays from 111 Bacillus-like strains. Moreover, the results showed that the compounds of the strain FJAT-57093 enriched by acid precipitation might be the main antibacterial metabolites. The strain FJAT-57093 also exhibited antibacterial effects against the aquatic pathogens Photobacterium damselae, Edwardsiella tarda, Vibrio parahaemolyticus, and Vibrio vulnificus. The safety assessment revealed that the strain FJAT-57093 was non-hemolytic and susceptible to ten antibiotics. The putative virulence and antibiotic resistance genes predicted were predominantly intrinsic to the FJAT-57093 genome. Furthermore, the strain FJAT-57093 demonstrated a tolerance of acid and bile salt under the simulated gastrointestinal tract conditions, extracellular enzyme-producing abilities, as well as an auto-aggregation rate of 45.88% at 24 h and co-aggregation rates with the aforementioned five aquatic pathogens, ranging from 14.87% to 58.55%. Additionally, its extracellular metabolites displayed strong antioxidant activities, with ABTS⁺ and DPPH radical scavenging rates of up to 99.82% and 42.74%, respectively. In summary, the strain B. velezensis FJAT-57093 was found to possess strong antibacterial activities against multiple aquatic pathogens and desirable in vitro probiotic properties. Full article

Background/Objectives: Deep eutectic solvents (DESs) have recently gained attention for their antimicrobial properties, particularly because they target both planktonic bacteria and biofilms. Among these, DESs based on α-hydroxy acids (αHAs) are of interest due to their inherent antibacterial properties and favorable biocompatibility. However, effects of the αHA molecular structure and hydrogen bonding ability within a DES formulation on biological activity has not yet been thoroughly investigated. Methods: This study systematically investigates DESs formed by combining glycolic acid, lactic acid or tartaric acid with either choline chloride or tetraethylammonium chloride. Results: All DESs demonstrate broad-spectrum antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa and effectively inhibit biofilm formation while exhibiting low cytotoxicity toward 3T3-L1 fibroblasts. Conclusions: DES formation enhances antibacterial efficacy while attenuating cytotoxicity compared to the individual components, thereby decoupling bactericidal activity from toxicity. Physicochemical characterization confirms the formation of a eutectic phase and reveals that biological activity is primarily governed by acidity rather than by the specific αHA structure or eutectic strength. These results provide new insights into structure-function relationships in DESs and establish a design strategy for biocompatible, non-cytotoxic antimicrobial agents. Full article

Curcumin has anti-tumour and antibacterial effects. In this research, fourteen kinds of piperidone monocarbonyl curcumin analogues with 3,5-dimethylene-4-piperidone as the parent scaffold and halogen substitution on both sides of the benzene ring were synthesized by Claisen–Schmidt reaction, and their anti-tumour effect, mechanism, and antibacterial activity were investigated. It was found that a series of curcumin analogues has different degrees of anti-tumour and antibacterial dual activity. Among them, 2,5-2Cl, 2Br-5Cl, 2-Cl, 2-F, and benzaldehyde have strong broad-spectrum anti-tumour effects and have obvious selective inhibitory effects on A549 cells. The IC₅₀ value is less than 5 μmol/L. The five promising compounds, respectively, inhibited the expression of AKT and ERK to induce apoptosis of A549 cells to varying degrees. The newly synthesized analogues 2,5-2Cl and 2Br-5Cl had stronger inhibitory effects on the growth of A549 cells than other analogues, and they tended to mainly inhibit the expression of AKT and ERK, respectively. However, 2-Cl and 2-F have significantly better inhibitory effects on methicillin-resistant Staphylococcus aureus (MRSA) than antibiotics. Taken together, piperidone monocarbonyl curcumin analogues may be developed as good candidates for potential prevention and treatment of cancer and bacterial infection complications. Full article

In this work, a novel polyvinyl alcohol/starch (PVA/St)-based composite film was fabricated by integrating citric acid (CA) and silver-loaded biochar (C-Ag) nanofillers to enhance antibacterial functionality. Sorghum straw-derived biochar was loaded with silver nanoparticles (AgNPs) through a green synthesis route using Peucedanum praeruptorum Dunn extract. The successful crosslinking by CA and the uniform incorporation of AgNPs were confirmed by FTIR, XRD, and SEM. Notably, the optimized composite film containing 1.5 g/L C-Ag exhibited strong broad-spectrum antibacterial activity, with inhibition zones of 28 mm against E. coli, 29 mm against S. aureus, and 26 mm against P. aeruginosa, respectively. The high efficacy is attributed to the synergistic effect between the sustained release of Ag⁺ and the CA-induced acidic microenvironment. This work provides a green and high-performance antibacterial material to address the potential microbe contamination. Full article

This study details the design, synthesis, and evaluation of a novel series of fourteen 2-((1H-1,2,4-triazol-5-yl)thio)-N-benzylidene-N-arylacetohydrazide hybrid compounds. The primary objective was to investigate their potential as antimicrobial agents and assess their cytotoxicity. A systematic approach combining in silico screening and experimental validation was employed. The initial in silico analysis, using SwissADME, identified compounds with favorable drug-like properties. Subsequently, all fourteen compounds were synthesized and characterized using various spectroscopic methods. Their antibacterial efficacy was evaluated in vitro against Gram-negative (Klebsiella aerogenes) and Gram-positive (Enterococcus sp.) bacteria through growth kinetics and colony-forming unit (CFU) assays. Cytotoxicity was assessed using MTT assays on HEK (human embryonic kidney) cell lines. The compound, 2-((1H-1,2,4-triazol-3-yl)thio)-N′-(2-fluorobenzylidene)-N-phenylacetohydrazide emerged as the most promising candidate, demonstrating broad-spectrum antibacterial activity. These findings highlight the potential of 2-((1H-1,2,4-triazol-5-yl)thio)-N-benzylidene-N-arylacetohydrazide hybrids as a scaffold for developing new antimicrobial agents. Furthermore, this study suggests possible environmental applications for these compounds in antimicrobial resistance (AMR) management. Full article

The escalating global crisis of antimicrobial-resistant (AMR) bacterial infections, along with the continuous threat of viral outbreaks, poses a serious risk to public health worldwide and underscores the urgent need for innovative therapeutic strategies. In this study, mesoporous silica nanoparticles (MSNs) were successfully synthesized and subsequently functionalized with copper to impart broad-spectrum antimicrobial activity. The oxidation state of copper on the MSN surface was modulated through thermal treatments, allowing the evaluation of its influence on antimicrobial efficacy. The modified MSNs were tested against key bacterial pathogens, including Escherichia coli and Staphylococcus aureus, achieving complete bactericidal activity after 2 h of exposure to E. coli. Moreover, as well as influenza A (H1N1) pdm09, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and MS2 bacteriophage (MS2) were evaluated, reaching an efficiency higher than 80%, 90%, and 97%, respectively. The results indicated that copper-modified MSNs exhibit potent antibacterial and antiviral activity, highlighting their potential as an antibiotic-free alternative for preventing microbial infections while mitigating the development of AMR bacteria. Full article

Senna petersiana (Bolle) Lock is a chemically diverse plant widely recognized for its ethnomedicinal applications across various traditional medical systems. It is native to and widely distributed in African countries, including Ethiopia, Cameroon, and South Africa. This review integrates the phytochemical composition, biological activities, and toxicological effects of S. petersiana. Phytochemical analyses reveal the presence of numerous classes of compounds, including alkaloids, flavonoids, phenolics, anthraquinones, chromones, and sterol glycosides, with variations in concentration across different plant parts. Quantitative studies highlight particularly high levels of phenolics and flavonoids in ethanol, methanol, and acetone extracts, correlating these with enhanced biological activities. Pharmacological investigations demonstrate a spectrum of activities, including antibacterial, antioxidant, anti-inflammatory, antiviral, anthelmintic, and anticancer effects, supporting many of the plant’s traditional uses. Toxicological assessments suggest relative safety at moderate doses, though further evaluation is necessary for specific cell types and high-dose exposures. Despite the promising bioactivities, the mechanisms of action and in vivo efficacy of isolated compounds remain underexplored. Future research should focus on bioassay-guided isolation, detailed pharmacodynamic studies, and comprehensive toxicological profiling to validate and harness the therapeutic potential of S. petersiana. This review highlights the plant’s biochemical complexity and paves the way for its development as a valuable phytopharmaceutical agent. Full article

Background/Objectives: Respiratory tract infections (RTIs) remain a leading cause of morbidity worldwide and are frequently associated with the emergence of multidrug-resistant pathogens. In this context, natural compounds represent a valuable source of novel antimicrobial and immunomodulatory agents. The present study aimed to evaluate the antibacterial, anti-inflammatory, and antioxidant activities of Protegol, a natural food supplement enriched in bioactive phytochemicals including hydroalcoholic extracts of propolis and hedge mustard (Sisymbrium officinale (L.) Scop.) aerial parts, together with honey, against clinically relevant bacterial strains and in cellular models of inflammation and oxidative stress. Furthermore, the ability of the multi-herbal formulation to alter the permeability of the bacterial cell wall was assessed. Methods: The antibacterial properties of Protegol were evaluated by determining its minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) against a panel of Gram-positive and Gram-negative bacteria, using the broth microdilution method. Cell wall permeability was investigated through the propidium iodide (PI) uptake assay. The anti-inflammatory potential was investigated in LPS-stimulated RAW 264.7 macrophages by measuring nitric oxide (NO) production with the Griess assay. The antioxidant activity was evaluated in BALB/3T3 fibroblasts exposed to hydrogen peroxide, using the DCFH-DA assay. Results: Protegol exhibited a broad-spectrum antibacterial effect, with MIC values ranging from 1.5 to 6.2 mg/mL and MBC values between 3.1 and 12.4 mg/mL. The strongest activity was observed against Staphylococcus aureus and Streptococcus pyogenes, including clinical isolates, while moderate efficacy was detected against resistant Klebsiella pneumoniae strains. PI uptake assays confirmed a dose-dependent disruption of bacterial membrane integrity, supporting a direct effect of Protegol on cell wall permeability. In macrophages, Protegol significantly and dose-dependently reduced NO release, lowering production to 44% at the highest concentration tested. In BALB/3T3 cells, Protegol markedly decreased ROS accumulation to 24% at the same concentration. Conclusions: Overall, the findings support the potential of Protegol as a natural adjuvant to the conventional therapies for respiratory tract health by counteracting bacterial pathogens, reducing inflammation, and mitigating oxidative stress, thereby supporting host defense mechanisms in the context of respiratory tract infections. Full article

The substantial interest in plant-based drugs or plant-derived phytocompounds drives researchers to conduct comprehensive investigations on their therapeutic properties. Mollugin, one of the major active constituents of Rubia cardifolia, has been well-studied for its pharmacological properties, demonstrating potent anti-inflammatory properties by suppressing the TAK-1-mediated activation of NF-κB/MAPK and enhancing the Nrf2/HO-1-mediated antioxidant response. It exhibits strong anticancer effects through ferroptosis via IGF2BP3/GPX4 pathways, induces mitochondrial apoptosis, and targets NF-κB, ERK, and PI3K/Akt/mTOR to suppress tumor progression. Mollugin also inhibits JAK2/STAT and PARP1 pathways, suppressing IL-1β expression via the modulation of ZFP91. Moreover, it regulates the MAPK/p38 pathway, promotes neuroprotection, and improves cognitive performance through GLP-1 receptor activation. Mollugin promotes osteogenesis by activating the BMP-2/Smad1/5/8 signaling pathway and downregulates MAPK, Akt, and GSK3β expression, leading to the inhibition of osteoclastogenesis. It overcomes multidrug resistance by downregulating MDR1/P-gp, CREB, NF-κB, and COX-2 through AMPK activation. Its antibacterial effect is mediated by strong binding to FUR, UDP, and IpxB proteins in Enterobacter xiangfangensis. Mollugin mitigates Klebsiella pneumoniae infection, suppresses adipogenesis without causing cytotoxicity, and protects endothelial cells via the BDNF/TrkB-Akt signaling pathway. Synthetic derivatives of mollugin, such as oxomollugin and azamollugin, have shown enhanced anticancer and anti-inflammatory effects by regulating EGFR, PKM2, TLR4/MyD88/IRAK/TRAF6, and NF-κB/IRF3 pathways with improved solubility and stability. Collectively, these findings emphasize the broad-spectrum activity of mollugin. This review provides a critical interpretation of the mechanistic pathways regulated by mollugin and its derivatives, emphasizing their pharmacological significance and exploring their potential for future translation as multitarget drug candidates. Full article

Nymphaea ‘Blue Bird’, a tropical water lily prized for its ornamental appeal, has been less explored as a source of bioactive flavonoids. This study developed an efficient extraction and purification protocol for flavonoids from this plant and compared their distribution and bioactivities across different tissues. Supercritical CO₂ fluid extraction (SFE) proved optimal, yielding 2.56% under conditions of 24.3 MPa, 39 °C, 91 min, and a CO₂ flow rate of 16 L/min. Subsequent purification with HPD500 macroporous resin enhanced flavonoid purity from 3.05% to 11.46%. Among the tissues analyzed, petals contained the highest levels of total flavonoids (6.43 mg/g) and total phenolics (45.71 mg/g), and exhibited the most potent antioxidant (as shown by the lowest EC₅₀ values for ABTS⁺ and DPPH scavenging) and broad-spectrum antibacterial activities (indicated by the lowest MIC and MBC against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans). Antibacterial efficacy was generally superior against Gram-positive bacteria. Widely targeted metabolomics identified 560 metabolites, predominantly flavonols and flavonoids. Principal component and cluster analyses revealed tissue-specific metabolite profiles. KEGG enrichment analysis underscored the significance of the flavonoid biosynthetic pathway, and key differential metabolites—such as luteolin, myricetin, taxifolin, and quercetin—were strongly correlated with the observed bioactivities. These results highlight N. ‘Blue Bird’ petals as a promising source of natural antioxidants and antimicrobials, providing a scientific basis for their future functional applications. Full article

The rapid rise of antimicrobial resistance (AMR) has emerged as a critical global health crisis, driven by the widespread emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) pathogens. This growing threat, coupled with the stagnation in the development of novel antibiotics, necessitates the investigation of alternative antimicrobial strategies. Plant-derived essential oils (EOs) have emerged as promising candidates due to their broad-spectrum antibacterial activity, multi-targeted mechanisms, and capacity to enhance the efficacy of existing antibiotics. Recent studies have underscored the potential of EOs in disrupting biofilms, inhibiting quorum sensing, modulating efflux pumps, and reversing resistance in a variety of bacterial pathogens, including those listed as priorities by the World Health Organization. Notably, many of these effects have been demonstrated against resistant strains isolated directly from clinical samples, thereby enhancing the translational significance of EOs. In addition to their antimicrobial properties, advances in analytical, omics-based, and microfluidic technologies have further elucidated the mechanisms of EOs and may accelerate their therapeutic development. Nevertheless, challenges such as variability in composition, lack of standardized testing protocols, and limited in vivo data continue to impede clinical application. Therefore, the aim of this scoping review is to critically examine the advances over the past decade in the antibacterial activity of plant EOs against clinical isolates, with a particular focus on their efficacy against resistant bacterial pathogens and their potential role in combating AMR. Full article

Background/Objectives: Despite their long history of clinical use, aminoglycosides remain important broad-spectrum antibiotics, exhibiting potent activity against Gram-positive, Gram-negative, and mycobacterial pathogens. However, the growing prevalence of antimicrobial resistance, along with the well-documented nephrotoxicity and ototoxicity associated with this class, underscores the urgent need for novel derivatives with enhanced pharmacological and safety profiles. Methods: In this study, we developed a synthetic approach for the synthesis of new apramycin derivatives featuring structural modifications at the 6″-position of 4-amino-4-deoxy-D-glucose residue, specifically through the introduction of aminoalkylamine and guanidinoalkylamine substituents. The synthesized compounds were evaluated for their antimicrobial activity against a broad panel of bacterial strains, including multidrug-resistant clinical isolates. Results: The obtained derivatives of apramycin demonstrated significant antibacterial activity, retaining potency against strains resistant to conventional aminoglycosides. Moreover, the new compounds exhibited the ability to circumvent aminoglycoside resistance mediated by enzymatic modification and showed reduced cytotoxicity in mammalian cell assays. Conclusions: The distinctive pharmacological properties of apramycin and its newly synthesized derivatives, particularly their resilience to common resistance mechanisms and low cytotoxicity, highlight apramycin as a valuable structural scaffold for the development of next-generation aminoglycoside antibiotics with improved efficacy and safety. Full article

Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs) and a major contributor to the global antimicrobial resistance crisis. The increasing prevalence of multidrug-resistant (MDR) strains, including expanded-spectrum β-lactamases (ESBL) and carbapenemase-producing isolates, severely limits treatment options. This review provides an overview on the key molecular mechanisms of UPEC antibiotic resistance, such as enzymatic inactivation, target-site mutations, efflux pump activity, and biofilm formation. Beyond conventional antibiotics, special emphasis is placed on phytochemical strategies as promising alternatives. Flavonoids, alkaloids, terpenoids, and essential oils exhibit antibacterial, anti-adhesive, and antibiofilm properties. These natural bioactive compounds modulate motility, suppress fimbrial expression, inhibit quorum sensing, and enhance antibiotic efficacy, acting both as standalone agents and as adjuvants. Current in vitro and in vivo studies highlight the potential of plant-derived compounds and biologically based therapies to combat UPEC. However, challenges related to standardization, bioavailability, and clinical validation remain unresolved. Integrating molecular mechanistic insights with advanced phytochemical research may offers a sustainable and effective strategy for mitigating UPEC antibiotic resistance. Full article

The emergence of bacterial infections as a critical public health challenge underscores the urgent need for innovative therapeutic strategies. We designed and synthesized a series of novel heteroaryl bishydrozono nitroimidazoles and their analogs by strategically hybridizing multiple molecular components through diverse linkers. Among the newly synthesized compounds, compound 4 displayed a broad-spectrum antibacterial profile with low cytotoxicity and hemolysis. It could inhibit the proliferation of methicillin-resistant Staphylococcus aureus and reduce its metabolic activity with low bacterial resistance. Further investigations revealed that the highly active compound 4 could not only disrupt cell membrane integrity and induce excessive reactive oxygen species within bacterial membranes, but also intercalate into DNA to form a supramolecular 4-DNA gyrase complex and cause cell death. These results demonstrated that compound 4 should have large potential as a promising candidate in the ongoing battle against resistant bacterial infections. Full article

Background/Objectives: Hepcidin is a cysteine-rich antimicrobial peptide that links iron homeostasis and innate immunity in vertebrates, but its functions in amphibians remain poorly understood. The Chinese spiny frog (Quasipaa spinosa) is an economically important species that suffers serious losses from bacterial diseases. This study aimed to identify and functionally characterize a hepcidin homolog (QsHep) from Q. spinosa, focusing on its antibacterial activity, immunomodulatory effects on primary macrophages, and protective efficacy against Elizabethkingia miricola infection. Methods: The QsHep gene was cloned and analyzed, its tissue distribution and inducible expression were examined by qRT-PCR, and the synthetic peptide was tested for antimicrobial, membrane-disruptive, and immunomodulatory activities in vitro, as well as for in vivo protection in an E. miricola infection model. Results: QsHep encodes a typical preprohepcidin with a signal peptide, prodomain, and a conserved mature peptide containing eight cysteine residues. QsHep was widely expressed, with the highest levels in liver, and was significantly upregulated in liver and spleen following bacterial challenge. Synthetic QsHep displayed broad-spectrum antibacterial activity, including strong inhibition of E. miricola, and induced dose-dependent membrane damage in E. miricola. QsHep showed no obvious cytotoxicity but significantly enhanced chemotaxis, phagocytic activity, and respiratory burst in primary macrophages. In vivo, QsHep treatment markedly improved the survival of E. miricola-infected frogs in a dose-dependent manner. Conclusions: QsHep is an amphibian hepcidin that combines membrane-disruptive antibacterial activity with the activation of macrophage effector functions and confers significant protection against bacterial infection in vivo. These findings expand our understanding of hepcidin-mediated innate immunity in amphibians and highlight QsHep as a promising peptide candidate for controlling bacterial diseases in frog aquaculture. Full article