Search Results (400)

Background: Neglected diseases caused by protozoan parasites remain a major public health burden, particularly in low- and middle-income countries. Among the chemical motifs explored in antiparasitic drug discovery, guanidine-containing compounds have attracted considerable attention due to their strong cationic character, high capacity for hydrogen bonding, and versatility in interacting with biological targets. Methodology: This review summarizes advances reported in the last decade regarding guanidine derivatives with activity against pathogens associated with Chagas disease, human African trypanosomiasis, Leishmaniasis, tuberculosis, toxoplasmosis, dengue and schistosomiasis. Results: Evidence gathered from synthetic, natural, and drug-repurposing studies indicates that the guanidine, guanidine-containing and guanidine-related compounds contribute to modulating biological activity by changing electrostatic interactions, hydrogen-bonding networks, and physicochemical properties, with enzymes, nucleic acids, and membrane-associated targets essential for parasite survival. Across the analyzed studies, several emerging structure–activity relationship trends were identified, including the contribution of polycationic or dicationic architectures, the influence of halogenated or lipophilic substituents, and the dependence of biological activity on the complete molecular framework, including heterocyclic systems, macrocycles, peptide conjugates, hybrid scaffolds, and repurposed drugs. In addition to direct antiparasitic effects, certain guanidine-containing and guanidine-related compounds demonstrate immunomodulatory or host-protective properties, expanding the therapeutic relevance of this class. Despite promising in vitro results, protonation trapping, efflux pump susceptibility, and pharmacokinetic limitations such as poor oral absorption, high polarity, plasma protein binding and limited membrane permeability remain significant challenges for clinical translation. Nonetheless, the integration of medicinal chemistry, computational modeling, and biological screening continues to accelerate the identification of optimized scaffolds. Conclusions: Overall, guanidine-based compounds constitute a promising scaffold for the development of new therapeutic strategies targeting neglected parasitic diseases, and further structural optimization may enable the emergence of candidates with improved efficacy, selectivity, and drug-like properties. Full article

Hydrophobic bioactive compounds, such as curcuminoids, β-carotene and long-chain lipids, as well as amphiphilic structural lipids (milk fat globule membrane (MFGM)-associated phospholipids), often exhibit low bioaccessibility due to poor aqueous solubility and/or susceptibility to degradation, which limits their effective use in functional foods. Buttermilk, a dairy byproduct enriched with proteins, lipids and MFGM components, provides a structurally complex, amphiphilic matrix that can enhance micellar solubilization, protect hydrophobic and amphiphilic compounds during digestion and thereby modulate their potential bioavailability. This systematic review and meta-analysis, conducted and reported in accordance with the PRISMA 2020 guidelines, synthesizes quantitative data from in vitro gastrointestinal digestion studies to evaluate the impact of buttermilk and related matrices (e.g., buttermilk yogurt, ultrafiltered buttermilk, and composite nanosystems) on the bioaccessibility of hydrophobic compounds and MFGM phospholipids compared with aqueous or non-buttermilk controls. We identified a limited but growing body of in vitro evidence indicating that buttermilk-based matrices generally increase the intestinal bioaccessibility of curcuminoids, β-carotene, omega-3 fatty acids, vitamin and MFGM phospholipids relative to non-buttermilk systems, with particularly pronounced effects in structured emulsions, yogurts, ultrafiltered buttermilk and MFGM-enriched nanosystems. Rather than a single effect size, the data point to a compound- and matrix-dependent spectrum of improvements, influenced by both the chemical nature of the bioactive and the supramolecular organization of the dairy matrix. Mechanistically, the available findings support a plausible hypothesis that buttermilk enhances bioaccessibility via MFGM-mediated micellar solubilization, interfacial protection against pH- and enzyme-driven degradation and favorable lipid partitioning, although these pathways remain to be confirmed in dedicated mechanistic and in vivo studies. Methodological heterogeneity and the exclusive reliance on in vitro models are important limitations, but overall, the synthesis supports buttermilk and MFGM-rich ingredients as sustainable, food-grade carriers for lipophilic nutraceuticals and highlights the importance of dairy matrix structure in the design of functional delivery systems. Full article

RNA viruses exhibit high mutation rates, necessitating antivirals targeting conserved infection mechanisms. In this study, viral hemorrhagic septicemia virus (VHSV), a non-human pathogenic negative-sense RNA virus, was used as a surrogate model to enable high-throughput antiviral screening under reduced biosafety conditions. A recombinant VHSV expressing enhanced green fluorescent protein was used to screen 17,265 compounds, 2000 plant extracts, and 100 marine extracts. Among the candidates, the leaf extract of Phellodendron amurense Rupr. (PL extract) exhibited antiviral activity with low cytotoxicity (selectivity index ≈ 10). The extract reduced viral infectivity in a dose-dependent manner and showed cross-activity against snakehead rhabdovirus. Mechanistic analyses indicated that the PL extract acts primarily at early stages of infection. Virucidal assays demonstrated direct, time-dependent inactivation of viral particles, while pre-treatment reduced host cell susceptibility. Time-of-addition experiments confirmed that antiviral activity was restricted to early infection, suggesting interference with viral attachment or entry rather than intracellular replication. Fractionation revealed that activity was associated with the non-polar n-hexane fraction, implicating lipophilic compounds that may disrupt viral envelope integrity or membrane interactions. These findings suggest that P. amurense leaf extract is a promising candidate for broad-spectrum antivirals targeting conserved entry processes in enveloped RNA viruses. Full article

Background: Carbonic Anhydrases (CAs) represent regulators of cell adaptation to hypoxia, pH regulation, and metabolic fitness. Among cancers, multiple myeloma (MM) is a plasma cell malignancy sustained by hypoxia-driven metabolic adaptation, extracellular acidification, and redox imbalance. Tight regulation of tumor extracellular pH, mediated by Carbonic Anhydrases IX and XII, is crucial for myeloma survival, progression, and stemness, making these isoforms attractive therapeutic targets. Methods: We designed and synthesized a library of terpenoid-based hybrids by derivatizing chlorothymol and 4-isopropyl-3-methylphenol with either the natural coumarin umbelliferon or the 2,2′-dipicolylamine (DPA) scaffold. This chemical strategy aimed to selectively inhibit tumor-associated CAs IX/XII through coumarin- or DPA-mediated recognition, while terpenoid fragments were introduced to enhance lipophilicity, membrane permeability, and potential redox-modulating properties. The compounds were tested by a Stopped-Flow assay for CA inhibition, in cell-based assays for antiproliferative properties and by means of several antioxidant assays. Results: The most active compounds, connecting the coumarin core to a terpenoid tail, inhibited the targeted CAs in the nanomolar range, showing up higher selectivity over off-target isoforms (I and II). In studies performed on MM cell lines, selected derivatives reduced viability (IC₅₀ = 15.8–85.4 µM) and displayed favorable selectivity over normal cells. In silico investigations suggested that the compounds were able to interact selectively with the target enzymes. Conclusions: Collectively, these results support a dual-targeting strategy in which selective inhibition of tumor-associated CAs, combined with redox modulation, interferes with adaptive mechanisms of MM cells, providing a rational framework for the development of multifunctional agents against metabolically resilient hematological malignancies. Full article

Background/Objectives: Hyperthermia coupled with temperature-triggered drug delivery systems, including drug-loaded thermosensitive liposomes, that exhibit increased membrane permeability at hyperthermia-relevant temperatures is a promising therapeutic strategy for cancer treatment. Our previous study revealed that nitrogen-doped carbon dots (CD) partially interact with the phospholipids of liposomes, increasing the membrane permeability of an encapsulated anticancer drug. In vitro cell experiments indicated that their presence in the culture medium, albeit at relatively high concentrations, also affect cell membrane permeability, enhancing drug internalization in cancer cells. This study aims to introduce either hydrophilic or lipophilic carbon dots into liposomes and evaluate them as thermosensitive drug delivery systems. Methods: Alkylated carbon dots (CD-C16) were synthesized and liposomal systems with either the lipophilic CD-C16 or the parent hydrophilic CD were prepared and efficiently loaded with doxorubicin (DOX). Following physicochemical characterization, their thermosensitivity was studied vs. time and temperature, while their effect on cell survival at 37 and 40 °C was evaluated against HEK293 and PC3 cells. Results: At 40 °C, for CD containing liposomes 50% DOX release is observed, whereas for CD-C16 containing liposomes 95% DOX is released within 5 min. Against PC3 cells at 40 °C, both DOX-loaded CD containing liposomes and CD-C16 containing liposomes are more potent compared to the parent drug-loaded liposomes, whereas CD-C16 containing liposomes are equally potent to free DOX. Against HEK293 cells the thermosensitive formulations at 40 °C prove even more cytotoxic, with CD-C16 containing liposomes being more potent than free DOX, but CD containing liposomes are advantageous for being less toxic than free DOX at 37 °C. Conclusions: Although work is needed to elucidate the mechanism at the molecular level, the results suggest that it is possible to adjust liposomal membrane permeability through the incorporation of carbon dots in order to optimize performance for hyperthermia-based applications. Full article

Cannabinol (CBN) is a highly lipophilic phytocannabinoid whose biomedical application is limited by poor water solubility. In this study, colloidal hydroxyapatite nanoparticles (nHAp) were evaluated as a carrier for CBN, and their effect on model lipid membranes was investigated. Interactions between CBN and lipids were examined using Langmuir monolayers and lipid bilayers (black lipid membranes, BLMs). Langmuir monolayer studies revealed strong interactions between CBN and lipids, resulting in changes in isotherms, compressibility, and monolayer stability. BLM measurements indicated that delivery of CBN via nHAp modifies the electrical properties and stability of the lipid bilayer, suggesting alterations in membrane organization and permeability. These results demonstrate that hydroxyapatite nanoparticles can effectively serve as a carrier for cannabinol while modulating its interactions with lipid membranes. Full article

Pruning residues from medicinal and aromatic plant cultivations represent an under-exploited biomass rich in bioactive metabolites. In this study, pruning by-products from Lavandula angustifolia Mill. ‘Essence Purple’ and Helichrysum italicum (Roth) G.Don were investigated as sources of essential oils (EOs) within a circular economy perspective. Micromorphological analyses confirmed the presence of secretory glandular trichomes in the residual biomass. EOs were obtained by steam distillation (0.33% and 0.15% yield for lavender and helichrysum, respectively) and chemically characterized by GC-FID and GC-MS. A total of 51 and 55 compounds were identified, accounting for 99.68% and 99.57% of the total composition. The main constituents were τ-cadinol (23.09%) and linalyl acetate (14.07%) in lavender EO and γ-curcumene (15.47%) and eudesm-4(14)-en-11-ol (10.71%) in helichrysum EO. Pruning-derived EOs showed a higher sesquiterpene content than those from conventional plant organs, indicating a compositional shift. Phytotoxic assays on Hordeum vulgare, Raphanus sativus, Lolium multiflorum, and Sinapis alba revealed concentration-dependent effects, with a stronger inhibition of radicle elongation than seed germination. These concentrations should be interpreted as indicative of intrinsic phytotoxic potential under controlled conditions. Ecotoxicological tests showed no significant reduction in viability in Artemia salina, whereas concentration- and time-dependent immobilization was observed in Daphnia magna, highlighting species-specific sensitivity, likely related to differences in the uptake and membrane interactions of lipophilic compounds. These findings highlight pruning residues as a promising biomass for the recovery of bioactive phytocomplexes with potential applications in sustainable weed management, although further studies under agronomically relevant conditions and comprehensive environmental assessments are required to validate their practical applicability. Full article

Multicomponent reactions with isocyanides (IMCRs) enable the one-step assembly of complex molecules and remain a powerful strategy for accessing bioactive scaffolds. Here, we report the first synthesis of an abietane diterpene isocyanide derived from aminoimide methyl maleopimarate 1, a levopimaric acid-maleic anhydride adduct. This isocyanide was further engaged in Passerini, Ugi, and azido-Ugi reactions to provide a series of α-acyloxy- and α-acylaminocarboxamides, as well as tetrazoles, in high yields under optimized conditions. The structures of all products were confirmed by comprehensive physicochemical analysis. In silico ADME, drug-likeness, target prediction, and toxicity studies (SwissADME, ProTox-III) revealed moderate lipophilicity with favorable membrane permeability and solubility, high gastrointestinal absorption, and selective CYP3A4 inhibition with no significant effects on other CYP450 isoforms. The compounds fulfill major drug-likeness criteria, lacking undesirable reactive fragments, with only acceptable deviations in molecular weight and flexibility typical for MCR-derived products. The modifications broaden the spectrum of predicted biological targets while maintaining low overall toxicity and absence of predicted hepato- or carcinogenicity. These results demonstrate that diterpene isocyanide is a valuable building block for chemical libraries of structurally diverse abietane derivatives with peptide-like termini and highlight its potential as a source of cytotoxic, antiviral, and anti-inflammatory candidates. Full article

Well-defined, small-molecule, platinum-centered coordination compounds are of continued interest in both basic and applied research, particularly in medicinal chemistry and pharmaceuticals (i.e., cisplatin). Organoplatinum(IV) complexes have been reported to exhibit substantial in vitro cytotoxicity across a range of cancer cell lines. Compared with coordinatively unsaturated platinum(II) species, electronically and coordinatively saturated platinum(IV) complexes are generally more inert, reducing undesirable side reactions in plasma and cellular environments and potentially improving their safety profiles as chemotherapeutic agents. In addition, the presence of organic ligands can enhance lipophilicity, facilitating passive diffusion across cell membranes. Here, we report the synthesis, structural characterization, and in vitro anticancer activity of a series of organoplatinum(IV) complexes of the general formula Pt(CH₃)₂I₂{n,n′-dimethyl-2,2′-bipyridine} (n,n′ = 4,4′; 5,5′; 6,6′). The 5,5′- and 6,6′-dimethyl isomers were characterized by single-crystal X-ray diffraction. All three dimethyl-substituted complexes, along with the parent compound, Pt(CH₃)₂I₂{2,2′-bipyridine}, were evaluated for cytotoxic activity against a panel of 60 human cancer cell lines. Whereas Pt(CH₃)₂I₂{2,2′-bipyridine} and the 4,4′- and 5,5′-dimethyl derivatives displayed limited cytotoxicity, the 6,6′-dimethyl isomer exhibited notable activity, particularly against the colon cancer cell line HCT-116 (LC₅₀ = 8.17 μM) and the ovarian cancer cell line OVCAR-3 (LC₅₀ = 7.34 μM). The enhanced cytotoxicity of the 6,6′-dimethyl derivative is attributed, at least in part, to the relatively facile dissociation of the 6,6′-dimethyl-2,2′-bipyridine ligand from the platinum(IV) center, suggesting that sterically induced ligand lability plays an important role in modulating biological activity in this particular compound, giving new structural activity impetus for potential drug molecules. Full article

Background/Objectives: Compounded vaginal creams are widely used for conditions such as hormone replacement therapy, vaginal dryness, low libido, vaginal infections, etc. Recent research highlights the potential of using anhydrous bases to extend shelf life, particularly when combined with self-emulsifying and mucoadhesive properties that improve mucosal retention and enhance drug bioavailability. This study provides in vitro and ex vivo evaluation of an anhydrous vaginal base. Methods: Key quality indicators such as irritation potential, leakage potential, pH compatibility, mucoadhesion, and self-emulsification were assessed using the chorioallantoic membrane Hen’s Egg Test, MTT assay, texture analysis, and fluorescence microscopy. Results: The anhydrous vaginal base demonstrated high cell viability (>78%) and non-irritant potential (IS = 2.5) in in vitro assays. It maintained physiological vaginal pH (4.56 ± 0.05), showed strong mucoadhesive properties comparable to commercial products, and exhibited minimal leakage. Ex vivo studies confirmed its prolonged retention on vaginal tissues. The anhydrous vaginal base formed stable emulsions upon contact with vaginal fluid simulant, effectively distributing both lipophilic and hydrophilic compounds. Conclusions: Compared to water-containing bases, an anhydrous vaginal base shows advantages: longer retention time and lower leakage; adaptability to varying vaginal fluid levels; and efficient dispersion of both hydrophilic and lipophilic active pharmaceutical ingredients. These features support its potential use in compounded vaginal products, minimizing stability risks and enhancing patient compliance and therapeutic outcomes. Full article

This review surveys how nanoparticles and biomolecular nanosized structures interact with model membrane systems, and how these interfacial processes govern their performance in drug and gene delivery, antimicrobial strategies, biosensing, and nanotoxicology. The nanostructures covered include polymeric nanoparticles, lipid-based carriers, peptide nanostructures, dendrimers, and multifunctional hybrids. Model membranes span Langmuir monolayers, supported lipid bilayers, vesicles/liposomes across sizes, and emerging hybrid or asymmetric constructs that better approximate native complexity. Mechanistically, interactions follow recurrent routes—surface adsorption, bilayer insertion, pore formation, and lipid extraction/reorganization—regulated by particle size, morphology, charge, ligand architecture, and lipophilicity, in conjunction with membrane composition, phase state, curvature, and asymmetry. A multiscale toolkit links structure, mechanics, and dynamics: Langmuir troughs and Brewster Angle Microscopy map thermodynamics and mesoscale morphology; atomic force microscopy and quartz crystal microbalance with dissipation resolve nanoscale topography and viscoelasticity; fluorescence microscopy/spectroscopy reports on localization and packing; neutron and X-ray reflectometry quantify vertical structure; molecular dynamics provides atomistic pathways and design hypotheses. Historically, the field advanced from early monolayers and bilayers, through the fluid mosaic model, to raft microdomains and modern biomimetic systems, enabling increasingly realistic experiments. Key advances include cross-method integration linking experimental observations with image-based computational models; persistent debates concern the translation from simplified models to living membranes, the role of dynamic coronas, and scale/force-field limits in simulations. Future efforts should prioritize hybrid models incorporating proteins and asymmetric lipidomes, standardized reporting and reference systems, rigorous coupling of experiments with calibrated simulations and machine learning, and alignment with safety-by-design and regulatory expectations, thereby shifting interfacial measurements from descriptive observation to predictive design rules. Full article

The optimization of membrane permeability is a pivotal approach for mitigating late-stage failures in peptide drug development. By leveraging linker chemical diversity, stapled peptides utilize linker engineering to precisely modulate key physicochemical parameters—such as lipophilicity and conformational constraints—to overcome the desolvation energy penalty. This review systematically evaluates linker-based strategies for enhancing the permeability of stapled peptides, categorized into two primary dimensions: (1) high-throughput screening (HTS) compatibility, focusing on the integration of functionalized linkers into mRNA display, phage display, and DNA-encoded libraries (DELs) to identify lead scaffolds with inherent permeability potential during early discovery; and (2) post-screening structural refinement, covering rational design strategies including intramolecular hydrogen-bond (IMHB) shielding, “chameleonic” adaptations, and stimuli-responsive reversible stapling. Furthermore, we analyze the paradigm shift in assessment methodologies from qualitative imaging to quantitative cytosolic delivery assays, which have deepened our understanding of mechanisms such as the charge/lipophilicity threshold balance and metabolism-driven trapping. Overall, linker engineering provides a robust technical roadmap for developing the next generation of cell-permeable stapled peptide therapeutics. Full article

Pancreatic ductal adenocarcinoma (PDAC) has limited effective therapeutic strategies. Statins inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and may affect tumor cell fitness via the mevalonate pathway, mitochondrial function, and redox homeostasis. We systematically compared seven statins in patient-derived PDAC cell lines and related viability effects to mitochondrial, redox, cell-cycle, apoptotic, and metabolic responses. Statins were tested in three PDAC cell lines (PDAC-1/2/3) using MTT assays (5–20 µM; 24–120 h). Based on MTT responses, mechanistic profiling was performed after 72 h at 20 µM concentration using lipophilic statins, including apoptosis (Annexin V/7-AAD), cell-cycle distribution, mitochondrial membrane potential (Δψm), intracellular ROS, and ¹H-NMR quantification of intracellular and extracellular metabolites. Statins reduced viability in a concentration- and time-dependent manner, with lipophilic statins more active than hydrophilic. PDAC-1 was highly sensitive, PDAC-3 intermediate, and PDAC-2 comparatively resistant. PDAC-1 and PDAC-3 showed G0/G1 accumulation, Δψm depolarization, reactive oxygen species (ROS) elevation, and Annexin V–positive apoptosis, whereas PDAC-2 (high basal ROS) showed ROS reduction and limited apoptosis despite Δψm loss. Metabolomics indicated reduced glucose and amino-acid utilization and lactate secretion while preserving line-specific metabolic fingerprints. PDAC cell lines display marked inter-tumoral heterogeneity in statin responses, supporting evaluation of statins as chemosensitizing adjuvants in functionally guided PDAC treatment strategies. Full article

Ginkgetin (GK) is a naturally occurring biflavonoid predominantly isolated from Ginkgo biloba and has attracted increasing attention because of its broad pharmacological activities. Structurally, GK belongs to the 3′-8″-linked biflavone subclass, which distinguishes it from other biflavonoids like amentoflavone (the parent compound of this subclass) and its monomeric counterparts such as apigenin. This unique C-C linked dimeric architecture confers distinct molecular planarity and lipophilicity, contributing to its enhanced membrane permeability and multitarget engagement capabilities. GK has been shown to exert pleiotropic biological effects in preclinical studies, including anti-inflammatory, antioxidant, antifibrotic, anticancer, neuroprotective, cardioprotective, metabolic regulatory and antibacterial activities. Mechanistically, preclinical evidence indicates that GK functions as a multitarget modulator of key signaling pathways involved in oxidative stress, inflammation, cell death and tissue remodeling, such as nuclear factor erythroid 2–related factor 2/heme oxygenase-1 (Nrf2/HO-1), nuclear factor kappa-B(NF-κB), Janus kinase/signal transducer and activator of transcription(JAK/STAT), mitogen-activated protein kinases(MAPKs), AMP-activated protein kinase/mechanistic target of rapamycin(AMPK/mTOR), phosphoinositide 3-kinase/protein kinase B(PI3K/Akt) and cyclic GMP-AMP synthase–stimulator of interferon genes(cGAS–STING). Notably, GK has been observed to display context-dependent regulation of cell fate decisions, including apoptosis, autophagy and ferroptosis, thereby enabling the selective elimination of pathological cells while preserving normal tissue function. Preclinical studies further demonstrate that GK exhibits therapeutic potential across diverse disease systems, including cancer, metabolic disorders, cardiovascular diseases, neurological disorders and musculoskeletal diseases. In addition, emerging evidence highlights its antibacterial and antivirulence properties through the inhibition of biofilm formation and quorum sensing. It is crucial to note, however, that this promising profile is predominantly derived from preclinical studies, and clinical evidence in humans remains to be established. Despite these promising findings, the clinical translation of GK remains limited by challenges related to pharmacokinetics, bioavailability and druggability. This review systematically summarizes the chemical characteristics, pharmacological activities and molecular mechanisms of GK, with an emphasis on its multitarget actions and therapeutic potential across disease systems, and discusses current limitations and future perspectives to facilitate the rational development of GK-based interventions. Full article

The high incidence of Candida albicans infections and the limited efficacy of current antifungal therapies highlight the need for new antifungal agents. In this study, we present a bio-based hybridization strategy aimed at enhancing the antifungal activity of natural product scaffolds, with a particular focus on trans-ferulic acid. A library of twenty-nine hybrid molecules was rationally generated by grafting naturally occurring lipophilic moieties onto either the phenolic or carboxylic acid functions of ferulic acid. The antifungal activity of these molecules was then assessed against C. albicans. While the parent natural compounds exhibited weak activity (MIC > 500 µM), several hybrid derivatives (ATF19, ATF20, and MB22) demonstrated enhanced potency, with MIC values of <50 µM. Esters of the carboxylic acid or phenol group were essential for activity, with the most potent effects observed for short linear or mildly branched lipophilic chains. These active compounds exerted a multifaceted anti-virulence effect, including mitochondrial membrane depolarization, inhibition of hyphal morphogenesis, alterations in cell wall composition, and strong suppression of biofilm formation. Additionally, lead compounds showed no detectable cytotoxicity in human macrophages and intestinal epithelial cells and significantly improved host survival in a Caenorhabditis elegans model of C. albicans infection. Overall, the ferulic acid, citronellol, and sinapic hybrid molecules emerged as promising lead compounds for the development of antifungals against C. albicans. Full article