Search Results (2,124)

Pseudomonas aeruginosa is a Gram-negative pathogen with a remarkable capacity to acquire multiple resistance mechanisms, severely limiting current therapeutic options. Consequently, the identification of new antimicrobial agents remains a critical priority. In this study, an integrated in silico-guided strategy was applied to identify small molecules with antibacterial potential against P. aeruginosa, targeting the quorum-sensing regulator LasR (PDB ID: 2UV0) and elastase (PDB ID: 1U4G). Pharmacophore modeling was performed for both targets, followed by ligand-based virtual screening, structure-based virtual screening (SBVS), and MM-GBSA (Molecular Mechanics-Generalized Born Surface Area) binding free energy calculations. Top-ranked compounds based on predicted binding affinity were selected for in vitro cytotoxicity and antibacterial evaluation. Antimicrobial activity was assessed against three P. aeruginosa strains: an American Type Culture Collection (ATCC) reference strain, a clinically susceptible isolate, and an extensively drug-resistant (XDR) clinical isolate. SBVS yielded docking scores ranging from −6.96 to −12.256 kcal/mol, with MM-GBSA binding free energies between −18.554 and −88.00 kcal/mol. Minimum inhibitory concentration (MIC) assays revealed that MolPort-001-974-907, MolPort-002-099-073, MolPort-008-336-135, and MolPort-008-339-179 exhibited MIC values of 62.5 µg/mL against the ATCC strain, indicating weak-to-moderate antibacterial activity consistent with early-stage hit compounds. MolPort-008-336-135 showed the most favorable activity against the clinically susceptible isolate, with an MIC of 62.5 µg/mL, while maintaining HepG2 cell viability above 70% at this concentration and an half-maximal inhibitory concentration (IC₅₀) greater than 500 µg/mL. In contrast, all tested compounds displayed MIC values above 62.5 µg/mL against the XDR isolate, reflecting limited efficacy against highly resistant strains. Overall, these results demonstrate the utility of in silico-driven approaches for the identification of antibacterial hit compounds targeting LasR and elastase, while highlighting the need for structure–activity relationship optimization to improve potency, selectivity, and activity against multidrug-resistant P. aeruginosa. Full article

Genomic instability not only drives tumor initiation and progression but also cooperates with apoptosis resistance to promote therapeutic evasion in hepatocellular carcinoma (HCC). Activation of MDM2, a negative regulator of p53, together with XIAP overexpression, represents a critical axis underlying this resistance. Simultaneous targeting of MDM2 and XIAP by MX69, a small molecule inhibitor, may therefore offer a potent interventional strategy to suppress cell proliferation and enhance pro-apoptotic signaling in HCC in vitro models. To evaluate the effects of MX69, cell viability was assessed via CVDK-8, colony formation, and real-time cell analysis. Oxidative stress levels and DNA damage were examined using fluorescence imaging and comet assays, respectively, while mitochondrial membrane potential was monitored through JC-1 staining. Furthermore, flow cytometry was employed to quantify apoptotic cell death and cell cycle distribution, while Western blot analysis was used to characterize the expression of apoptosis-related proteins. In vitro cytotoxicity assays revealed that MX69 reduced the viability of HUH7 and Hep3B cells in a dose-dependent manner, suppressed colony formation, and exerted anti-proliferative effects in real-time proliferation assays. Cell viability and IC50 values were evaluated using CVDK-8 and RTCA assays. Furthermore, MX69 induced oxidative stress and mitochondrial dysfunction, as evidenced by elevated ROS levels and loss of mitochondrial membrane potential. This was accompanied by significant DNA damage, detected by comet assay and γ-H2AX immunofluorescence, and G0–G1 cell cycle arrest. Moreover, MX69 triggered apoptotic cell death, demonstrating potent anticancer activity. Collectively, our findings identify MDM2/XIAP dual inhibition by MX69 as a promising therapeutic approach in HCC, with potential to overcome apoptosis resistance linked to genomic instability. Full article

This study explores the taxonomic diversity, metabolic profile, and bioactivity of marine-derived actinomycetes isolated from sediments collected off the coast of Lisbon and Setúbal Peninsula, Portugal. The combined use of two sediment pre-treatments (heat shock and dry overnight) and four growth media with varying nutrient concentrations revealed that formulations 10% A1 and SWA were most effective for recovering diverse actinomycetes, including rare Actinomadura, resulting in a total of 142 cultivable strains closely related to 47 phylogenetic distinct species dominated by Streptomyces and Micromonospora. Antimicrobial screening against methicillin-resistant Staphylococcus aureus (MRSA, COL) and Escherichia coli (K12) identified 22 bioactive strains, with strain PTS-083 exhibiting the strongest activity against MRSA (MIC = 1.95 µg/mL) and a 98.30% 16S rRNA gene identity to S. chumphonensis, highlighting it as a strong candidate for further metabolite and genomic studies. Cytotoxicity assays against HCT-116 human colorectal adenocarcinoma cells revealed eight bioactive strains with potent anticancer activity for extracts from strains related to S. sundarbansensis, S. violaceorubidus, and S. aculeolatus (IC₅₀ < 0.005–5.08 µg/mL). Untargeted LC-MS/MS metabolomic analysis uncovered a wide array of secondary metabolites, including macrolides, siderophores, fatty acids, and cyclic peptides. Comparative analyses with other Portuguese coastal studies revealed both shared and distinctive metabolomic profiles, emphasizing the importance of exhaustive sampling, even at nearby locations, as their localized environmental conditions can influence metabolic diversity. These findings highlight Portugal’s coastal sediments as a rich and underexplored source of novel actinomycetes and bioactive compounds with promising pharmaceutical applications. Exhaustive sampling of marine sediment actinomycete communities, even at nearby locations, is crucial for discovering unique metabolites with potential biotechnological value. Full article

Spodoptera frugiperda is a major pest affecting maize production worldwide, and its control relies heavily on synthetic insecticides, which generate environmental risks and resistance. Essential oils (EOs) represent a promising alternative due to their biodegradability and the biological activity of their terpenoid constituents. This study evaluated the chemical composition, larvicidal activity, and acetylcholinesterase (AChE) inhibitory potential of the EOs from Origanum vulgare, Lavandula dentata, and Mentha piperita against S. frugiperda larvae at the L1, L2, and L4 instars. Chemical characterization by GC–MS revealed distinct chemotypes: a phenolic/terpenoid profile in O. vulgare, a 1,8-cineole-type profile in L. dentata, and a menthol-rich composition in M. piperita. Larvicidal assays showed dose- and stage-dependent responses, and M. piperita EO tended to produce the most robust mortality across instars and times, consistently producing high mortality (75%) at 90 µg·mL⁻¹ air concentration. AChE inhibition assays revealed that carvacrol and menthone were the most active constituents with IC₅₀ values of 312–330 µg·mL⁻¹. Molecular docking supported these results, as carvacrol and menthone showed the most favorable interactions with amino acid residues of the AChE catalytic site. These data support their suitability as candidates for integrated pest management programs targeting S. frugiperda. Future research should focus on formulation strategies, synergistic combinations, detoxification mechanisms, and field validation. Full article

Seasonal freeze–thaw cycles profoundly alter soil physical properties in cold-region agroecosystems, yet their effects on the mechanical behavior of the ice–soil interface remain poorly quantified. This interface plays a critical role in governing soil structural stability, detachment resistance, and subsequent erosion processes during thaw periods, particularly in the black soil region of Northeast China. In this study, controlled laboratory experiments were conducted to investigate the evolution of ice–soil interface mechanical properties under varying freeze–thaw conditions using cultivated black soils. Key parameters, including interface shear strength and bonding characteristics, were quantified across different freeze–thaw cycles. The results demonstrate that freeze–thaw action significantly weakens the mechanical integrity of the ice–soil interface, with pronounced reductions in shear strength observed after repeated cycles. This degradation is attributed to ice lens formation, pore structure disruption, and the redistribution of interfacial water films during freezing and thawing. Notably, the rate and magnitude of strength loss exhibit strong sensitivity to freeze–thaw frequency, highlighting the cumulative nature of freeze-induced damage at the interface scale. These findings provide mechanistic insights into how freeze–thaw processes modulate soil resistance to external forces during early thaw periods, offering an improved physical basis for understanding soil erosion vulnerability in cold agricultural regions. The results have direct implications for soil conservation strategies and erosion modeling under ongoing climate warming, which is expected to intensify freeze–thaw dynamics in seasonally frozen farmlands. Full article

The increasing demand for plant-based alternatives, driven by veganism, lactose intolerance, and greater health consciousness, has intensified research into dairy-free frozen desserts. This study investigates the development of a plant-based ice cream alternative utilizing oleosomes extracted from sunflower seed kernels as natural emulsifiers, eliminating the need for synthetic additives. Oleosomes were obtained through aqueous extraction from raw kernels, incorporated into emulsions in three levels (0, 12, and 24%), and combined with sunflower seed oil, tahini, date paste, and water to create the ice cream (IC) formulations. The physicochemical properties of three formulations of a sugar-free frozen dessert were studied. Physicochemical analyses assessed nutritional value, color (CIELab), melting time, stability, overrun, viscosity, and texture profile (TPA). Sensory evaluation was conducted using a hedonic test to assess the impact of tahini type (sunflower seed tahini or pumpkin seed kernel tahini) on the product acceptance. Results showed that higher oleosome content improved emulsion stability and melting resistance, while also producing a softer (30.74 ± 0.28 N), less adhesive (1.87 ± 0.20 mJ) texture, suitable for plant-based ice cream. Sensory analysis revealed a clear preference for the pumpkin tahini formulation, which scored 8.21 ± 0.62 for overall appreciation. The findings demonstrate that the addition of oleosome might improve textural attributes of the products, while the consumer preference could also be influenced by the type of tahini involved in the formulation. However, further studies are necessary to corroborate the proposed interaction mechanisms of ingredients. Full article

Background: 8-Hydroxyquinoline and phthalimide are two significant heterocyclic scaffolds in medicinal chemistry due to their pharmacological profiles. Hybridizing these pharmacophores and further modifying them via modified Mannich reactions provides a strategy to improve their physicochemical parameters and selectivity toward multidrug-resistant (MDR) cancer cells. Objectives: To synthesize a series of 8-hydroxyquinoline–phthalimide hybrids and their Mannich base derivatives and evaluate their cytotoxic activity and resistance-selective properties against sensitive Colo205 and resistant Colo320 cancer cell lines. Methods: Four hybrid compounds were synthesized by reacting 5-amino-8-hydroxyquinoline with different phthalic anhydride derivatives. Twelve fine-tuned derivatives were prepared by using the modified Mannich reaction. Cytotoxic activity was measured using the MTT assay, and relative resistance (RR) was calculated to determine selectivity toward the resistant cell line. P-glycoprotein (Pgp) ATPase activity was evaluated for the most active compounds. Results: All derivatives displayed cytotoxic activity, with higher potency toward the resistant Colo320 cell line. Compounds 2 and 4 showed the strongest activity against both cell lines (IC₅₀ down to 4.88 µM). Compounds 5, 8a, 9a, and 9c retained potent activity against Colo320 (IC₅₀ = 9.89–22.79 µM). Incorporating a CH₂–N group at position C7 substantially enhanced the selectivity for MDR cells. Compounds 9c, 9a, and 8a exhibited the highest selectivity, with RR values of 0.29, 0.33, and 0.35, respectively. Compounds 2, 4, 5, 8a, and 9a showed inhibitory effects on Pgp ATPase activity. Conclusion: The newly synthesized HQ–phthalimide hybrids represent promising candidates for targeting MDR in colorectal cancer, with Mannich modification enhancing the selectivity toward resistant cells. Full article

Due to the indiscriminate use of antimicrobial drugs in the treatment of infectious diseases, human pathogenic bacteria have developed resistance to many commercially available antibiotics. Medicinal plants such as Convolvulus arvensis represent a renewable resource for the development of alternative therapeutic agents. This study aimed to evaluate the antibacterial activity of silver nanoparticles (AgNPs) biosynthesized from C. arvensis against two clinical antibiotic-resistant bacterial isolates. The pathogenic isolates were identified as Staphylococcus aureus MRSA and Escherichia coli ESBL using 16S rRNA gene sequencing. Silver nanoparticles were synthesized via a green synthesis approach, and their physicochemical properties were characterized using UV–Vis spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, zeta potential, and dynamic light scattering (DLS). The synthesized C. arvensis–AgNPs exhibited a surface plasmon resonance peak at 475 nm and predominantly spherical morphology with particle sizes ranging from 102.34 to 210.82 nm. FTIR analysis indicated the presence of O–H, C–O, C–N, C–H, and amide functional groups. The nanoparticles showed a zeta potential of −18.9 mV and an average hydrodynamic diameter of 63 nm. The antibacterial activity of the biosynthesized AgNPs was evaluated against methicillin-resistant S. aureus (MRSA and ATCC 29213) and E. coli (ESBL and ATCC 25922) using agar diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Inhibition zones ranged from 10 to 13 mm, with MIC and MBC values of 12.5–25 µg/mL and 25–50 µg/mL, respectively. In addition, the nanoparticles exhibited antioxidant activity (DPPH assay, IC₅₀ = 0.71 mg/mL) and anti-inflammatory effects as determined by protein denaturation inhibition. No cytotoxic effects were observed in the MCF-7 cell line at the MIC level. These findings suggest that C. arvensis–AgNPs have potential as natural antimicrobial, antioxidant, and anti-inflammatory agents. Full article

This study investigates the unsteady motion of a slender body in a fluid beneath an ice cover, both in the presence and absence of the ocean waves propagating through the ice–water system, using the Fourier and Laplace integral transforms. The influence of the progressive wave on ice cover deflections, specifically the Bernoulli hump and Kelvin wake angle, induced by the motion of the underwater body near the surface, is analyzed numerically. Additionally, the effect of the progressive wave on the wave resistance of the body is investigated. Conditions are derived that relate the L/D ratio to a dimensionless parameter characterizing the elastic forces of the plate, under which the presence of the ocean wave produces a minimal effect on the body’s wave resistance. Full article

The irrational or excessive use of antibiotics causes the emergence of bacterial resistance, making antibiotics less effective or ineffective. As the number of resistant antibiotics increases, it is crucial to develop new strategies and innovative approaches to potentiate the efficacy of existing antibiotics. Prior to this, we discovered that some of the traditional antibiotics produce reactive oxygen species (ROS) under specific light exposure. In this paper, we report a multifunctional polymeric nanoparticle (F8IC NPs-PME) that combines targeted and photodynamic–photothermal therapy (PDT-PTT) in one device. The PME on the surface of F8IC enables the selective binding of F8IC NPs-PME to the surface of Gram-negative bacteria. In addition, PME and F8IC can generate ROS and photothermia under near-infrared light excitation, respectively. The results showed that the sterilization efficiency of F8IC NPs-PME at a concentration of 8 μg/mL was as high as 94.7% against kanamycin-resistant E. coli under 808 nm near-infrared light irradiation (0.8 W/cm², 10 min). This antimicrobial strategy can achieve efficient bacteria killing with a low dosage of antibiotics and opens up a new avenue for fighting bacterial resistance. Full article

Background/Objectives: Triple negative breast cancer (TNBC) is an aggressive subtype treated primarily with chemotherapy, which often leads to drug resistance (DR) and reduced effectiveness. Phytochemicals, including anthocyanins from dark sweet cherry (ACN), have emerged as potential adjuvants to overcome DR, though mechanisms remain unclear. This study examines ACN effects on canonical and non-canonical antioxidant pathways (Nrf2-Keap1 and p62) as a mechanism to overcome DR in 4T1 TNBC cells with acquired DR. Methods: Two conditions were tested: ACN with basal doxorubicin (DOX) as resistance-maintaining conditions and ACN with DOX at IC₅₀ to induce oxidative stress (OS). Results: Under resistance-maintaining conditions, ACNs activated the canonical Nrf2-Keap1 pathway at high doses, which can potentially contribute to DR development due to its cellular protection effects. However, at a low dose, ACN did not trigger an antioxidant response linked to GST and GGT enzyme activities and instead impaired autophagy, increasing OS. Under OS, ACN activated the non-canonical antioxidant pathway mediated by p62 while deactivating Nrf2, leading to autophagy-induced cell death and further impairing autophagy at a low dose. Notably, inflammation persisted at both treatment levels without being relieved, keeping stress signaling active. At both conditions, ACN at doses likely attainable under physiological conditions effectively impaired autophagy and elevated OS, resulting in cell death. Conclusions: These results underscore the context-dependent dual function of polyphenols in cancer therapy, demonstrating their potential to enhance cellular sensitivity to chemotherapy and providing guidance for their strategic use as adjuvants in treating TNBC and overcoming DR. However, this study was limited to a single cell line derived from a murine model. Future research should include comparative studies using human TNBC cell lines to validate these findings and better assess their translational relevance. Full article

The spotted knifejaw (Oplegnathus punctatus) has emerged as a species with substantial potential for aquaculture development in China. However, its industrial cultivation is severely constrained by viral diseases. Among these, viral nervous necrosis (VNN), caused by nervous necrosis virus (NNV), represents a critical bottleneck to the sustainable development of this industry. In order to elucidate the immune response mechanisms of the brain cells of spotted knifejaw, this study established a poly (I:C) stimulation model in vitro and performed transcriptomic sequencing to analyze the differentially expressed genes (DEGs) after stimulation. There were 3169, 3228, and 3262 DEGs at 3 h, 6 h, and 12 h compared to 0 h (control), respectively. Co-expression time clustering of DEGs identified two gene clusters (cluster 6 and cluster 10), which included several immune-related genes. GO and KEGG enrichment analyses indicated that DEGs among the four time points were significantly enriched in immune signaling pathways, including the NOD-like receptor, RIG-I-like receptor, C-type lectin receptor, and Toll-like receptor pathways, as well as disease-response pathways. In total, 1398 common DEGs were identified among three comparative groups, which delineated six interaction clusters and 30 hub genes in protein–protein interaction (PPI) network analysis. By integrating a cellular model with transcriptomics, this study provides preliminary insights into the molecular immune mechanisms underlying the response of brain cells to poly (I:C) stimulation, offering important theoretical support for future research on disease-resistant breeding and disease control strategies in spotted knifejaw. Full article

Three new pyrrole alkaloids, streptopyrroles D–F (1–3), along with four known analogs (4–7) were isolated from Sea Anemone-Associated Streptomyces sp. S1502 via an OSMAC (One Strain Many Compounds)-based strategy. Their structures were elucidated through comprehensive spectroscopic analyses, including HRESIMS and 1D/2D NMR experiments (COSY, HSQC, and HMBC), and further confirmed by X-ray crystallography. Biological evaluation identified streptopyrrole (4) as an anti-MRSA (methicillin-resistant Staphylococcus aureus) agent, while 4 and 6 displayed broad-spectrum cytotoxicity and good selectivity against a panel of human cancer cell lines. Notably, 4 and 6 showed particularly potent activity against the lung cancer cell lines H1299, SW1573, and A549, with IC₅₀ values ranging from 5.43 to 16.24 μM. Further mechanistic investigation revealed that both compounds suppress the proliferation of lung cancer cells by inducing cell cycle arrest at the G₀/G₁ phase and impair metastatic potential by inhibiting migration and invasion. These findings not only expand the structural diversity of marine-derived pyrrole alkaloids but also reveal the anticancer mechanisms of 4 and 6, highlighting their promise as active candidates for further antitumor drug development, particularly in lung cancer. Full article

Epithelial ovarian cancer (EOC) represents the most lethal malignancy arising from the female reproductive tract, largely due to the clinical challenge of chemotherapy resistance. Recent studies indicate that ferroptosis—a distinct form of programmed cell death driven by iron accumulation and lipid peroxidation, could potentially exploit a vulnerability in chemoresistant cancer cells. Here, we identify MED12 as a critical regulator of ferroptosis sensitivity in EOC through modulation of the YAP–TEAD1 signaling pathway. Using CRISPR/Cas9-mediated knockout and rescue experiments in EOC cell lines, we demonstrate that MED12 deficiency significantly enhances sensitivity to ferroptosis inducers (RSL3 and Erastin), as evidenced by reduced IC50 values. Transcriptomic and chromatin accessibility analyses reveal that MED12 loss activates YAP signaling through TEAD1 upregulation, increasing chromatin accessibility at YAP–TEAD1 target loci and elevating the expression of downstream effectors CYR61 and CTGF. Pharmacological inhibition of YAP with verteporfin or siRNA-mediated TEAD1 knockdown reverses ferroptosis sensitivity in MED12-deficient cells, confirming pathway specificity. These findings establish MED12 as a modulator of the YAP–TEAD1–ferroptosis axis and suggest that targeting this pathway could overcome chemoresistance in MED12-deficient EOC. Our work provides a mechanistic foundation for exploiting ferroptosis induction as a therapeutic strategy in ovarian cancer. Full article

PARP inhibitors are a clinically validated class of anticancer therapeutics that exploit synthetic lethality to target homologous recombination-deficient tumors, such as those carrying BRCA1/2 mutations. Nevertheless, the rational design of mitochondria-targeted PARP inhibitors capable of selective mitochondrial accumulation and organelle-specific PARP modulation remains an unresolved objective. To enable organelle-specific modulation of PARP activity, we synthesized a series of trialkyl(aryl)phosphonium conjugates of olaparib and rucaparib designed to target mitochondria by cardiolipin binding. Their activity was evaluated by PARP1 inhibition, cardiolipin affinity, and cytotoxicity in BRCA1-deficient HCC1937 breast cancer cells and non-malignant H9C2 cardiomyocytes. All conjugates retained potent PARP1 inhibition (IC₅₀ = 3.4–17 nM), comparable to the parent drugs. Several derivatives, particularly compounds 2d and 6c, exhibited strong cardiolipin binding (EC₅₀ = 12.99 µM and 6.77 µM, respectively) and significantly enhanced cytotoxicity in HCC1937 cells (IC₅₀ = 0.93 and 2.01 µM), outperforming olaparib and rucaparib. Notably, cytotoxicity toward H9C2 cells was lower, indicating a favorable selectivity profile. Phosphonium conjugation preserves PARP1 inhibitory activity while conferring mitochondrial targeting and enhanced anticancer potency. These findings support the development of mitochondria-targeted PARP inhibitors as a next-generation therapeutic strategy with the potential to improve efficacy and overcome resistance in HR-deficient tumors. Full article