Search Results (3,377)

Physiological levels of reactive oxygen species (ROS) play a crucial role as intracellular signaling molecules, helping to maintain cellular homeostasis. However, when ROS accumulate excessively, they become toxic to cells, leading to damage to lipids, proteins, and DNA. This oxidative stress can impair cellular function and lead to various forms of cell death, including apoptosis, necroptosis, ferroptosis, pyroptosis, paraptosis, parthanatos, and oxeiptosis. Despite their significance, the role of ROS in autosis (an autophagy-dependent form of cell death) remains largely unexplored. In this review, we gather current knowledge on autotic cell death and summarize how oxidative stress influences the activity of Beclin-1 and the Na⁺,K⁺-ATPase pump, both of which are critical effectors of this pathway. Finally, we discuss the theoretical potential for ROS to modulate this type of cell death, proposing a possible dual role for these species in autosis regulation through effectors such as HIF-1α, TFEB, or the FOXO family, and highlighting the need to experimentally address cellular redox status when working on autotic cell death. Full article

Modern agriculture relies heavily on the use of pesticides, with one-third of them being herbicides. Chloroacetamides are the most widely used herbicides because of their high effectiveness, but their extensive use poses environmental challenges and threatens the health of living organisms due to toxicity risks. Since the pharmacokinetic behavior and toxicity of a compound are influenced by its lipophilicity, this essential physicochemical parameter for disubstituted chloroacetamides was determined in silico and experimentally through thin-layer chromatography on reversed phases (RPTLC C18/UV254s) in mixtures of water and distinct organic modifiers. The pharmacokinetic profile of chloroacetamides was analyzed by using the BOILED-Egg model. The correlation between the obtained chromatographic parameters and software-based lipophilicity, pharmacokinetic, and ecotoxicity predictors of the studied chloroacetamides was assessed by using linear regression, but more comprehensive insight was obtained through multivariate methods—Cluster Analysis and Principal Component Analysis. It was observed that the total number of carbon atoms in the structure of their molecules, along with the type of hydrocarbon substituents, are the most important factors affecting lipophilicity, pharmacokinetics, and potential toxicity to non-target organisms. Full article

Background/Objectives: Cancer suffers from unresolved therapeutic challenges owing to the lack of targeted therapies and heightened recurrence risk. This study aimed to investigate the new series of hydroxamate by structurally modifying the pharmacophore of vorinostat. Methods: The present work involves the synthesis of 15 differently substituted 2H-1,2,3-triazole-based hydroxamide analogs by employing triazole ring as a cap with varied linker fragments. The compounds were evaluated for their anticancer effect, especially their anti-breast cancer response. Molecular docking and molecular dynamics simulations were conducted to examine binding interactions. Results: Results indicated that among all synthesized hybrids, the molecule VI(i) inhibits the growth of MCF-7 and A-549 cells (GI₅₀ < 10 μg/mL) in an antiproliferative assay. Compound VI(i) was also tested for cytotoxic activity by employing an MTT assay against A549, MCF-7, and MDA-MB-231 cell lines, and the findings indicate its potent anticancer response, especially against MCF-7 cells with IC₅₀ of 60 µg/mL. However, it experiences minimal toxicity towards the normal cell line (HEK-293). Mechanistic studies revealed a dual-pathway activation: first, apoptosis (17.18% of early and 10.22% of late apoptotic cells by annexin V/PI analysis); second, cell cycle arrest at the S and G2/M phases. It also promotes ROS generation in a concentration-dependent manner. The HDAC–inhibitory assay, extended in silico molecular docking, and MD simulation experiments further validated its significant binding affinity towards HDAC 1 and 6 isoforms. DFT and ADMET screening further support the biological proclivity of the title compounds. The notable biological contribution of VI(i) highlights it as a potential candidate, especially against breast cancer cells. Full article

The search for sustainable, economically viable, and effective plant protection strategies against pathogenic bacteria, fungi, and viruses is a major challenge in modern agricultural practices. Chitosan (CS) is an abundant cationic natural biopolymer known for its biocompatibility, low toxicity, and antimicrobial properties. Its potential use in agriculture for pathogen control is a promising alternative to traditional chemical fertilisers and pesticides, which raise concerns regarding public health, environmental protection, and pesticide resistance. This study focused on the preparation of chitosan nanoparticles (CS-NPs) through cross-linking with organic molecules, such as tannic acid (TA). Various formulations were explored for the development of stable nanoscale particles having encapsulation capabilities towards low compounds of varying polarity and with potential agricultural applications relevant to plant health and growth. The solution properties of the NPs were assessed using dynamic and electrophoretic light scattering (DLS and ELS); their morphology was observed through atomic force microscopy (AFM), while analytical ultracentrifugation (AUC) measurements provided insights into their molar mass. Their properties proved to be primarily influenced by the concentration of CS, which significantly affected its intrinsic conformation. Additional structural insights were obtained via infrared and UV–Vis spectroscopic measurements, while detailed fluorescence analysis with the use of three different probes, as model cargo molecules, provided information regarding the hydrophobic and hydrophilic microdomains within the particles. Full article

Efflux is one of the key mechanisms used by Gram-negative bacteria to reduce internal antibiotic concentrations. These active transport systems recognize and expel a wide range of toxic molecules, including antibiotics, thereby contributing to reduced antibiotic susceptibility and allowing the bacteria to acquire additional resistance mechanisms. To date, unlike other resistance mechanisms such as enzymatic modification or target mutations/masking, efflux is challenging to detect and counteract in clinical settings, and no standardized methods are currently available to diagnose or inhibit this mechanism effectively. This review first outlines the structural and functional features of major efflux pumps in Gram-negative bacteria and their role in antibiotic resistance. It then explores various strategies used to curb their activity, with a particular focus on efflux pump inhibitors under development, detailing their structural classes, modes of action, and pharmacological potential. We discuss the main obstacles to their development, including the structural complexity and substrate promiscuity of efflux mechanisms, the limitations of current screening methods, pharmacokinetic and tissue distribution issues, and the risk of off-target toxicity. Overcoming these multifactorial barriers is essential to the rational development of less efflux-prone antibiotics or of efflux pump inhibitors. Full article

Phthalate esters (PAEs), frequently detected in various environmental media, are associated with multiple health issues, particularly reproductive toxicity. This study employed molecular docking and molecular dynamics simulations to investigate the reproductive toxicity risk of 22 PAEs on the regulation of the hypothalamic–pituitary–gonadal (HPG) axis. Analysis revealed that when the carbon number of PAEs was the same, those with branched side chains exhibited more pronounced reproductive toxicity risks. In PAE molecules with branched side chains, reproductive toxicity risk was inversely proportional to the number of carbon atoms. Furthermore, five PAE molecules with unacceptable risk (DIPRP, DMEP, DMP, DPP, and DUP) and four key indicators were proposed. Key descriptors influencing PAEs’ reproductive toxicity risks were identified as Infrared and ATSC8e by machine learning analysis. Furthermore, carbonyl structure, substituent position, and electronegativity of PAE molecules are critical factors influencing PAE-induced reproductive toxicity risks via the HPG axis. This study provides a theoretical basis for further investigation of PAE-induced reproductive toxicity risk on the HPG axis, which facilitates the development of risk mitigation strategies for PAEs’ reproductive toxicity and provides novel perspectives and approaches for exploring the molecular mechanisms underlying the endocrine effects of emerging contaminants such as PAEs. Full article

Estrogen receptor alpha (ERα) plays a vital role in the development and progression of breast cancer by regulating the expression of genes associated with cell proliferation in breast tissue. ERα inhibition is a key strategy in the prevention and treatment of breast cancer. Previous research modified chalcone compounds into pyrazoline benzenesulfonamide derivatives (Modifina) which show activity as an ERα inhibitor. This study aimed to design novel pyrazoline benzenesulfonamide derivatives (PBDs) as ERα antagonists using in silico approaches. Structure-based and ligand-based drug design approaches were used to create drug target molecules. A total of forty-five target molecules were initially designed and screened for drug likeness (Lipinski’s rule of five), cytotoxicity, pharmacokinetics and toxicity using a web-based prediction tools. Promising candidates were subjected to molecular docking using AutoDock 4.2.6 to evaluate their binding interaction with ERα, followed by molecular dynamics simulations using AMBER20 to assess complex stability. A pharmacophore model was also generated using LigandScout 4.4.3 Advanced. The molecular docking results identified PBD-17 and PBD-20 as the most promising compounds, with binding free energies (ΔG) of −11.21 kcal/mol and −11.15 kcal/mol, respectively. Both formed hydrogen bonds with key ERα residues ARG394, GLU353, and LEU387. MM-PBSA further supported these findings, with binding energies of −58.23 kJ/mol for PDB-17 and −139.46 kJ/mol for PDB-20, compared to −145.31 kJ/mol, for the reference compound, 4-OHT. Although slightly less favorable than 4-OHT, PBD-20 demonstrated a more stable interaction with ERα than PBD-17. Furthermore, pharmacophore screening showed that both PBD-17 and PBD-20 aligned well with the generated model, each achieving a match score of 45.20. These findings suggest that PBD-17 and PBD-20 are promising lead compounds for the development of a potent ERα inhibitor in breast cancer therapy. Full article

Background/Objectives: The incorporation of bioactive molecules into mesoporous carriers is a promising strategy to improve stability, solubility, and therapeutic efficacy. In this study, we report for the first time the encapsulation of the synthetic chalcone 4-Cl into KIT-6 mesoporous silica and evaluate its cytotoxicity, toxicological profile, and pharmacological activities (antinociceptive, anti-inflammatory, and anxiolytic) using an in vivo zebrafish (Danio rerio) model. Methods: Zebrafish were orally dosed with 4-Cl, 4-Cl/KIT-6, or KIT-6 (4, 20, 40 mg/kg) and mortality was recorded for 96 h. For analgesia, zebrafish pretreated with 4-Cl, 4-Cl/KIT-6, KIT-6, or morphine received a tail stimulus (0.1% formalin). Locomotor activity (quadrant crossings) was monitored for 30 min to assess analgesia (neurogenic: 0–5 min; inflammatory: 15–30 min). For inflammation, abdominal edema and weight gain were assessed 4 h after intraperitoneal carrageenan (1.5%). Zebrafish (n = 6/group) received 4-Cl, 4-Cl/KIT-6, or KIT-6 (4, 20, 40 mg/kg, p.o.). Controls received ibuprofen (100 mg/kg, p.o.) or 3% DMSO. Weight was measured hourly for 4 h post-carrageenan (difference between baseline and hourly weights). Results: Physicochemical characterizations confirmed successful encapsulation without compromising the ordered structure of KIT-6, as evidenced by a significant reduction in surface area and pore volume, indicating efficient drug incorporation. In vivo assays demonstrated that the 4-Cl/KIT-6 formulation maintained the pharmacological activities of the free chalcone, reduced toxicity, and, notably, revealed a significant anxiolytic effect for the first time. Conclusions: These findings highlight KIT-6 as a promising platform for chalcone delivery systems and provide a solid basis for future preclinical investigations. Full article

Cancer has remained one of the leading causes of death worldwide throughout history despite significant advancements in drug development, radiation therapy, and surgery. Traditional chemotherapeutic small molecules are often hindered by narrow therapeutic indices and limited specificity, leading to suboptimal clinical outcomes. On the other hand, more advanced approaches, such as antibody–drug conjugates (ADCs), frequently encounter obstacles, including poor tumor penetration and prohibitive production costs. The tumor-forming and metastatic capacity of cancer further challenges currently available cancer therapies by creating a biochemical milieu known as the tumor microenvironment (TME). Although solid tumor development presents significant obstacles, it also opens new avenues for innovative therapeutic approaches. It is well-documented that as tumors grow beyond 1–2 mm³ in size, they undergo profound changes in their microenvironment, including alterations in oxygen levels, pH, enzymatic activity, surface antigen expression, and the cellular composition of the stroma. These changes create unique opportunities that can be exploited to develop novel and innovative therapeutics. Currently, numerous ADCs, small-molecule–drug conjugates (SMDCs), and prodrugs are being developed to target specific aspects of these microenvironmental changes. In this review, we explore five TME parameters in detail, with a focus on their relevance to specific cancer types, phenotypic identifiers, and preferred methods of therapeutic targeting. Additionally, we examine the chemical moieties available to target these changes, providing a framework for design strategies that exploit the dynamics of the tumor microenvironment. Full article

Some studies performed in our laboratory on pyrrole and its derivatives pointed towards the enrichment of the evaluations of these promising chemical structures for the potential treatment of neurodegenerative conditions in general and Parkinson’s disease in particular. A classical Paal-Knorr cyclization approach is applied to synthesize the basic hydrazine used for the formation of the designed series of hydrazones (15a–15g). The potential neurotoxic and neuroprotective effects of the newly synthesized derivatives were investigated in vitro using different models of induced oxidative stress at three subcellular levels (rat brain synaptosomes, mitochondria, and microsomes). The results identified as the least neurotoxic molecules, 15a, 15d, and 15f applied at a concentration of 100 µM to the isolated fractions. In addition, the highest statistically significant neuroprotection was observed for 15a and 15d at a concentration of 100 µM using three different injury models on subcellular fractions, including 6-hydroxydopamine in rat brain synaptosomes, tert-butyl hydroperoxide in brain mitochondria, and non-enzyme-induced lipid peroxidation in brain microsomes. The hMAOA/MAOB inhibitory activity of the new compounds was studied at a concentration of 1 µM. The lack of a statistically significant hMAOA inhibitory effect was observed for all tested compounds, except for 15f, which showed 40% inhibitory activity. The most prominent statistically significant hMAOB inhibitory effect was determined for 15a, 15d, and 15f, comparable to that of selegiline. The corresponding selectivity index defined 15f as a non-selective MAO inhibitor and all other new hydrazones as selective hMAOB inhibitors, with 15d indicating the highest selectivity index of >471. The most active and least toxic representative (15d) was evaluated in vivo on Rotenone based model of Parkinson’s disease. The results revealed no microscopically visible alterations in the ganglion and glial cells in the animals treated with rotenone in combination with 15d. Full article

Tellurite (TeO₃²⁻) is a highly soluble and toxic oxyanion that inhibits the growth of Escherichia coli at concentrations as low as ~1 µg/mL. This toxicity has been primarily attributed to the generation of reactive oxygen species (ROS) during its intracellular reduction by thiol-containing molecules and NAD(P)H-dependent enzymes. However, under anaerobic conditions, E. coli exhibits significantly increased tellurite tolerance—up to 100-fold in minimal media—suggesting the involvement of additional, ROS-independent mechanisms. In this study, we combined chemical-genomic screening, untargeted metabolomics, and targeted biochemical assays to investigate the effects of tellurite under both aerobic and anaerobic conditions. Our findings reveal that tellurite perturbs amino acid and nucleotide metabolism, leading to intracellular imbalances that impair protein synthesis. Additionally, tellurite induces notable changes in membrane lipid composition, particularly in phosphatidylethanolamine derivatives, which may influence biophysical properties of the membrane, such as fluidity or curvature. This membrane remodeling could contribute to the increased resistance observed under anaerobic conditions, although direct evidence of altered membrane fluidity remains to be established. Overall, these results demonstrate that tellurite toxicity extends beyond oxidative stress, impacting central metabolic pathways and membrane-associated functions regardless of oxygen availability. Full article

Animal venoms are complex biochemical secretions rich in highly potent and selective bioactive molecules, including peptides, enzymes, and small organic compounds. Once associated primarily with toxicity, these venoms are now recognized as a promising source of therapeutic agents for a wide range of medical conditions. This review provides a comprehensive analysis of the pharmacological potential of venom-derived compounds, highlighting their mechanisms of action, such as ion channel modulation, receptor targeting, and enzyme inhibition. Successful venom-derived drugs like captopril and ziconotide exemplify the translational potential of this biological arsenal. We discuss therapeutic applications in cardiovascular diseases, chronic pain, cancer, thrombosis, and infectious diseases, as well as emerging peptide candidates in clinical development. Technological advancements in omics, structural biology, and synthetic peptide engineering have significantly enhanced the discovery and optimization of venom-based therapeutics. Despite challenges related to stability, immunogenicity, and ecological sustainability, the integration of AI-driven drug discovery and personalized medicine is expected to accelerate progress in this field. By synthesizing current findings and future directions, this review underscores the transformative potential of animal venoms in modern pharmacotherapy and drug development. We also discuss current therapeutic limitations and how venom-derived compounds may address unmet needs in specific disorders. Full article

The development of novel platinum-based anticancer agents remains a critical objective in medicinal inorganic chemistry, particularly in light of resistance and toxicity limitations associated with cisplatin. In this study, the synthesis, structural characterization, quantum chemical analysis, and cytotoxic evaluation of four new acetylplatinum(II) complexes (cis-[Pt(COMe)₂(PASO₂)₂], cis-[Pt(COMe)₂(DAPTA)₂], trans-[Pt(COMe)Cl(DAPTA)₂], and trans-[Pt(COMe)Cl(PASO₂)]: 1–4, respectively) bearing cage phosphine ligands PASO₂ (2-thia-1,3,5-triaza-phosphaadamantane 2,2-dioxide) and DAPTA (3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane) are presented. The coordination geometries and NMR spectral features of the cis/trans isomers were elucidated through multinuclear NMR and DFT calculations at the B3LYP/6-311++G(d,p)/LanL2DZ level, with strong agreement between experimental and theoretical data. Quantum Theory of Atoms in Molecules (QTAIM) analysis was applied to investigate bonding interactions and assess the covalent character of Pt–ligand bonds. Cytotoxicity was evaluated against five human cancer cell lines. The PASO₂-containing complex in cis-configuration, 1, demonstrated superior activity against thyroid (8505C) and head and neck (A253) cancer cells, with potency surpassing that of cisplatin. The DAPTA complex 2 showed enhanced activity toward ovarian (A2780) cancer cells. These findings highlight the influence of ligand structure and isomerism on biological activity, supporting the rational design of phosphine-based Pt(II) anticancer drugs. Full article

Alpha-Synuclein (α-Syn) is a presynaptic neuronal protein implicated in the pathogenesis of Parkinson’s disease (PD) and other synucleinopathies, primarily through its aggregation into insoluble fibrils. The extended α-Syn half-life necessitates treatment durations that are incompatible with efficient high-throughput drug screening, can risk compound stability or cause cellular toxicity. To address this, we inserted a PEST sequence, a motif known to promote rapid protein degradation, at the C-terminus of the SNCA gene using CRISPR/Cas9 to create a novel cell line with reduced α-Syn half-life. This modification accelerates α-Syn turnover, providing a robust model for studying α-Syn dynamics and offering a platform that is applicable to other long-lived proteins. Our results demonstrate a six-fold reduction in α-Syn half-life, enabling the rapid detection of changes in protein levels and facilitating the identification of molecules that modulate α-Syn production and degradation pathways. Using inhibitors of the proteasome, transcription, and translation further validated the model’s utility in examining various mechanisms that impact protein levels. This novel cell line represents a significant advancement for studying α-Syn dynamics and offers promising avenues to develop therapeutics for α-synucleinopathies. Future research should focus on validating this model in diverse experimental settings and exploring its potential in high-throughput screening applications. Full article

Background/Objectives: Magnetic resonance imaging (MRI) is a powerful, non-invasive diagnostic tool capable of capturing detailed anatomical and physiological information. MRI contrast agents enhance image contrast but, especially linear gadolinium-based compounds, have been associated with safety concerns. This has prompted interest in alternative contrast agents. Manganese-based contrast agents offer a promising substitute, owing to manganese’s favorable magnetic properties, natural biological role, and strong T1 relaxivity. This review aims to critically assess the structure, mechanisms, applications, and challenges of manganese-based contrast agents in MRI. Methods: This review synthesizes findings from preclinical and clinical studies involving various types of manganese-based contrast agents, including small-molecule chelates, nanoparticles, theranostic platforms, responsive agents, and controlled-release systems. Special attention is given to pharmacokinetics, biodistribution, and safety evaluations. Results: Mn-based agents demonstrate promising imaging capabilities, with some achieving relaxivity values comparable to gadolinium compounds. Targeted uptake mechanisms, such as hepatocyte-specific transport via organic anion-transporting polypeptides, allow for enhanced tissue contrast. However, concerns remain regarding the in vivo release of free Mn²⁺ ions, which could lead to toxicity. Preliminary toxicity assessments report low cytotoxicity, but further comprehensive long-term safety studies should be carried out. Conclusions: Manganese-based contrast agents present a potential alternative to gadolinium-based MRI agents pending further validation. Despite promising imaging performance and biocompatibility, further investigation into stability and safety is essential. Additional research is needed to facilitate the clinical translation of these agents. Full article