Binding Affinity Research Articles

In-silico assessment of novel peptidomimetics inhibitor targeting STAT3 and STAT4 N-terminal domain dimerization: A comprehensive study using molecular docking, molecular dynamics simulation, and binding free energy analysis

Dysregulation in Janus kinase-Signal Transducer and Activation of Transcription (JAK-STAT) pathway is closely linked to various cancer types. The N-terminal domain (NTD) of STAT proteins, upon dimerization, assumes a multifaceted role with remarkable adaptability in mediating interactions between proteins. Consequently, the strategic targeting of the N-terminal domain of STATs has emerged as a promising tactic for disrupting dimerization and impeding the translocation of STAT proteins. In this study, we have deployed an integrated in-silico methodology to rationally design Peptidomimetic foldamers as inhibitors of the N-terminal domains of STAT3 and STAT4, with the objective of disrupting protein dimerization. Consequently, we have judiciously designed a series of peptidomimetics that encompass β3-amino acids, bearing side chains that mimic the residues within interface II of the dimeric structures of the NTDs. Employing molecular docking techniques; we have assessed the binding affinity of these designed peptidomimetics toward both the NTDs. Furthermore, we have conducted an evaluation of the stability and conformational alterations within the docked complexes over an extensive Molecular Dynamics, subsequently computing the binding free energy utilizing MM/PBSA calculations. Our findings unequivocally demonstrate that the peptidomimetic foldamers we have devised (Peptide-A, Peptide-B, and Peptide-C) exhibit a propensity to bind to and impede the dimerization process of the NTDs of both STAT3 and STAT4. These outcomes serve to underscore the potential of these meticulously designed peptidomimetics as potential candidates meriting further exploration in the realm of cancer prevention and management.

PFOS and PFOSA induce oxidative stress-mediated cardiac defects in zebrafish via PPARγ and AHR pathways, respectively

Perfluorooctane sulfonate (PFOS) and its precursor, perfluorooctane sulfonamide (PFOSA), are widespread in the environment. Evidence suggests a strong link between maternal exposure to PFOS/PFOSA and congenital heart diseases in the offspring, but the underlying mechanisms remain unclear. We hypothesized that PFOS and PFOSA induce cardiac defects through the peroxisome proliferator-activated receptor gamma (PPARγ) and aryl hydrocarbon receptor (AHR) pathways, respectively. In this study, we demonstrated that exposing zebrafish embryos to either PFOSA or PFOS caused cardiac malformations and dysfunction. Both PFOS and PFOSA induced reactive oxygen species (ROS) overproduction, mitochondrial damage, and apoptosis in zebrafish larvae hearts. Blockade of PPARγ through either pharmaceutical inhibition or genetic knockdown only attenuated the changes caused by PFOS, but not those elicited by PFOSA. Conversely, inhibition of AHR alleviated the adverse effects induced by PFOSA but not by PFOS. Both PFOSA and PFOS exhibited similar binding affinities to AHR using molecular docking techniques. The varying ability of PFOS and PFOSA to induce AHR activity in zebrafish embryonic hearts can be attributed to their different capabilities for activating PPARγ. In summary, our findings indicate that PFOS and PFOSA induce excessive ROS production in zebrafish larvae via the PPARγ and AHR pathways, respectively. This oxidative stress in turn causes mitochondrial damage and apoptosis, leading to cardiac defects.

Decreased formulation pH and protein preheating treatment enhance the interaction, storage stability, and bioaccessibility of caseinate-bound lutein/zeaxanthin

Heat treatment and pH are crucial factors in the formulation and processing of food and beverages; thus, a thorough understanding of the impact of these factors on the interactions between bioactive constituents and proteins is essential to developing effective protein-based delivery systems. This study explores the influences of pH (ranged from 1.5 to 7.5) and preheating treatment on the characteristics of caseinates-lutein (LU)/zeaxanthin (ZX) complexes and evaluates the potential application of caseinates as protective carriers in xanthophyll-fortified beverages. The properties and interactions of caseinates and two xanthophylls were systematically investigated utilizing a range of spectroscopic techniques, including ultraviolet–visible (UV–Vis) spectroscopy, dynamic light scattering (DLS), fluorescence spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. Caseinates were bound to LU/ZX with a binding constant of the order 105 M−1. Furthermore, ZX exhibited a higher affinity for caseinates than LU. In particular, the decreased pH level of complex formulation and the preheating of caseinates at 85 °C strengthened the binding affinity between LU/ZX and caseinates. The caseinate-LU/ZX complexes effectively improved the chemical stability of LU/ZX and achieved a bioaccessibility rate of over 70 %. This study provides a guide for developing commercially available xanthophyll-fortified beverages and further expanding the application of caseinates as encapsulation carriers for extremely hydrophobic nutrients in the food industry.

Unraveling the chemotherapeutic potential of taxifolin ruthenium-p-cymene complex in breast carcinoma: Insights into AhR signaling pathway in vitro and in vivo

BackgroundMammary carcinoma is the most frequently diagnosed form of carcinoma in women worldwide. The organometallic compounds showed a prospective anticancer activity. This research explored the anticancer efficacy of taxifolin ruthenium-p-cymene counter to breast cancer. MethodsThe anticancer efficacy of the novel organometallic compound was investigated via various in vitro and in vivo techniques using breast cancer cell lines and breast cancer model of rat. ResultsTarget proteins were identified via pharmacophore analysis, which revealed a high binding affinity towards AhR, EGFR, and β-catenin. The compound induced apoptotic events and prevented cancer cell colony formation. Furthermore, decreased expression of AhR, EGFR, and N-cadherin inhibited cancer cell growth, migration, and proliferation. The compound provoked the cell cycle arrest at sub G0/G1 phase, S phase and G2/M phase and inaugurated the caspase-3 dependent apoptotic events. The in-vivo experimentation displayed the fruitful restoration of breast tissue since the complex treatment in DMBA persuaded breast carcinoma in rat. Moreover, the upstream of p53 and caspase-3 expression along with substantially downstream of vimentin, β-catenin, m-TOR and Akt expression. ConclusionsIn conclusion, the compound repressed the cancerous cellular viability, migration, and EMT via modulating the AhR/EGFR/ PI3K transduction pathway and the expression of EMT biomarkers such as N-cadherin, E-cadherin, thus eventually revoked the EMT facilitated metastasis of malignant cells.

In silico advancements in Peptide-MHC interaction: A molecular dynamics study of predicted glypican-3 peptides and HLA-A*11:01

Our study employed molecular dynamics (MD) simulations to assess the binding affinity between short peptides derived from the tumor-associated antigen glypican 3 (GPC3) and the major histocompatibility complex (MHC) molecule HLA-A*11:01 in hepatocellular carcinoma. We aimed to improve the reliability of in silico predictions of peptide-MHC interactions, which are crucial for developing targeted cancer therapies. We used five algorithms to discover four peptides (TTDHLKFSK, VINTTDHLK, KLIMTQVSK, and STIHDSIQY), demonstrating the substantial potential for HLA-A11:01 presentation. The Anchored Peptide-MHC Ensemble Generator (APE-Gen) was used to create the initial structure of the peptide-MHC complex. This was followed by a 200 ns molecular dynamics (MD) simulation using AMBER22, which verified the precise positioning of the peptides in the binding groove of HLA-A*11:01, specifically at the A and F pockets. Notably, the 2nd residue, which serves as a critical anchor within the 2nd pocket, played a pivotal role in stabilising the binding interactions.VINTTDHLK (ΔGSIE = −14.46 ± 0.53 kcal/mol and ΔGMM/GBSA = −30.79 ± 0.49 kcal/mol) and STIHDSIQY (ΔGSIE and ΔGMM/GBSA = −14.55 ± 0.16 and −23.21 ± 2.23 kcal/mol) exhibited the most effective binding potential among the examined peptides, as indicated by both their binding free energies and its binding affinity on the T2 cell line (VINTTDHLK: IC50 = 0.45 nM; STIHDSIQY: IC50 = 0.35 nM). The remarkable concordance between in silico and in vitro binding affinity results was of particular significance, indicating that MD simulation is a potent instrument capable of bolstering confidence in in silico peptide predictions. By employing MD simulation as a method, our study provides a promising avenue for improving the prediction of potential peptide-MHC interactions, thereby facilitating the development of more effective and targeted cancer therapies.

Exploring antithrombotic mechanisms and effective constituents of Lagopsis supina using an integrated strategy based on network pharmacology, molecular docking, metabolomics, and experimental verification in rats

Ethnopharmacological relevanceThrombosis is a common cause of morbidity and mortality worldwide. Lagopsis supina (Stephan ex Willd.) Ikonn.-Gal. ex Knorring is an ancient Chinese herbal medicine used for treating thrombotic diseases. Nevertheless, the antithrombotic mechanisms and effective constituents of this plant have not been clarified. Aim of the studyThis work aimed to elucidate the pharmacodynamics and mechanism of L. supina against thrombosis. Materials and methodsSystematic network pharmacology was used to explore candidate effective constituents and hub targets of L. supina against thrombosis. Subsequently, the binding affinities of major constituents with core targets were verified by molecular docking analysis. Afterward, the therapeutic effect and mechanism were evaluated in an arteriovenous bypass thrombosis rat model. In addition, the serum metabolomics analysis was conducted using ultra-high performance liquid chromatography coupled with Q-Exactive mass spectrometry. ResultsA total of 124 intersected targets of L. supina against thrombosis were predicted. Among them, 24 hub targets were obtained and their mainly associated with inflammation, angiogenesis, and thrombosis approaches. Furthermore, 9 candidate effective constituents, including (22E,24R)-5α,8α-epidioxyergosta-6,22-dien-3β-ol, aurantiamide, (22E,24R)-5α,8α-epidioxyergosta-6,9 (11),22-trien-3β-ol, lagopsinA, lagopsin C, 15-epi-lagopsin C, lagopsin D, 15-epi-lagopsin D, and lagopsin G in L. supina and 6 potential core targets (TLR-4, TNF-α, HIF-1α, VEGF-A, VEGFR-2, and CLEC1B) were acquired. Then, these 9 constituents demonstrated strong binding affinities with the 6 targets, with their lowest binding energies were all less than −5.0 kcal/mol. The antithrombotic effect and potential mechanisms of L. supina were verified, showing a positively associated with the inhibition of inflammation (TNF-α, IL-1β, IL-6, IL-8, and IL-10) and coagulation cascade (TT, APTT, PT, FIB, AT-III), promotion of angiogenesis (VEGF), suppression of platelet activation (TXB2, 6-keto-PGF1α, and TXB2/6-keto-PGF1α), and prevention of fibrinolysis (t-PA, u-PA, PAI-1, PAI-1/t-PA, PAI-1/u-PA, and PLG). Finally, 14 endogenous differential metabolites from serum samples of rats were intervened by L. supina based on untargeted metabolomics analysis, which were closely related to amino acid metabolism, inflammatory and angiogenic pathways. ConclusionOur integrated strategy based on network pharmacology, molecular docking, metabolomics, and in vivo experiments revealed for the first time that L. supina exerts a significant antithrombotic effect through the inhibition of inflammation and coagulation cascade, promotion of angiogenesis, and suppression of platelet activation. This paper provides novel insight into the potential of L. supina as a candidate agent to treat thrombosis.

Enhancing the thermal stability and activity of zearalenone lactone hydrolase to promote zearalenone degradation via semi-rational design

Zearalenone (ZEN) is a fungal toxin produced by Fusarium exospore, which poses a significant threat to both animal and human health due to its reproductive toxicity. Removing ZEN through ZEN lactonase is currently the most effective method reported, however, all published ZEN lactonases suffer from the poor thermal stability, losing almost all activity after 10 min of treatment at 55℃. In this study, we heterologously expressed ZHD11A from Phialophora macrospora and engineered it via semi-rational design. A mutant I160Y-G242S that can retain about 40 % residual activity at 55℃ for 10 min was obtained, which is the most heat-tolerant ZEN hydrolase reported to date. Moreover, the specific activity of the I160Y-G242S was also elevated 2-fold compared to ZHD11A from 220 U/mg to 450 U/mg, which is one of the most active ZEN lactonses reported. Dynamics analysis revealed that the decreased flexibility of the main-chain carbons contributes to increased thermal stability and the improved substrate binding affinity and catalytic turnover contribute to enhanced activity of variant I160Y-G242S. In all, the mutant I160Y-G242S is an excellent candidate for the industrial application of ZEN degradation.

Histological evaluation of renal progenitor/stem cells, renal mesenchymal stem-like cells, and endothelial progenitor cells in chronic kidney disease and end-stage renal disease, and molecular docking analysis of drug-receptor interactions

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are prevalent and debilitating conditions with a significant impact on patients' quality of life. In this study, we conducted a comprehensive investigation into the histological characteristics of renal progenitor/stem cells (RPCs), renal mesenchymal stem-like cells, and endothelial progenitor cells (EPCs) in CKD and ESRD patients. Additionally, we performed a molecular docking analysis to explore potential drug-receptor interactions involving common medications prescribed to CKD patients. Our histological examination revealed a noteworthy increase in the number of CD24- and CD133-positive cells in CKD and ESRD patients, representing RPCs. These cells are implicated in kidney repair and regeneration, underscoring their potential role in CKD management. Moreover, we observed an elevation in the number of EPCs within the kidneys of CKD and ESRD patients, suggesting a protective role of EPCs in kidney preservation. The molecular docking analysis unveiled intriguing insights into potential drug interventions. Notably, digoxin exhibited the highest in-silico binding affinity to numerous receptors associated with the functions of RPCs, renal mesenchymal stem-like cells, and EPCs, emphasizing the potential multifaceted effects of this cardiac glycoside in CKD patients. Other drugs, including apixaban, glimepiride, and glibenclamide, also displayed strong in-silico affinities to specific receptors, indicating their potential influence on various renal cell functions. In conclusion, this study provides valuable insights into the histological alterations in renal cell populations in CKD and ESRD patients and underscores the potential roles of RPCs and EPCs in kidney repair and preservation. The molecular docking analysis reveals the complex interactions between common drugs and renal cells, suggesting the need for further in-vitro and in-vivo research to fully understand these relationships. These findings contribute to our understanding of CKD and offer new avenues for research into potential therapeutic interventions.

Photo- and thermo-responsive poly(ionic liquid) hydrogel regulated by hierarchical host–guest interactions

Supramolecular hydrogels constructed through various host–guest interactions have attracted tremendous attention in view of their excellent dynamic and multi-stimuli responsive performances. Herein, benzyl (Bn) and azobenzene (Azo) grafted poly(ionic liquid)s (PILs) were prepared via a one-pot post-synthesis strategy. By virtue of the difference in binding affinity of Azo and Bn groups with the host compound cucurbituril [8] urea (CB[8]), the newly-developed supramolecular hydrogels exhibited distinctive photo- and thermo-responsive behaviors. Under UV light irradiation, PIL-Azo-Bn/CB[8] hydrogel got weaker, while a gel-to-sol transition was observed when treated by heating. Moreover, the above tunable behaviors were highly reversible. Variable-temperature measurements such as proton nuclear magnetic resonance and ultraviolet–visible spectroscopy illustrated that the photo- and thermo-regulated performances of PIL hydrogel were ascribed to the hierarchical host–guest interactions. As a prototype application in smart circuits, PIL hydrogel exhibited a photo- and thermo-tuned conductivity. Thus, our finding presented a novel and versatile platform to fabricate responsive functional hydrogels via host–guest interactions, which has great promising applications in smart materials and flexible sensors.

Thiazole-derived pyrazin-2-carbohydrazide chemosensors: Colorimetric & photoluminescent detection of silver ions for theoretical, environmental, and cell imaging

In this work, a simple and versatile chemosensor receptor TZPYZ was synthesized through the combination of thiazole with pyrazine-2-carbohydrazide, resulting in a confirmed chemical structure via various analytical techniques including FT-IR, 1H, and 13C Nuclear Magnetic Resonance Spectroscopy, as well as High-Resolution Mass Spectroscopy analysis. TZPYZ exhibits specific colorimetric and photoluminescent responses to Ag+ ions in a solvent solution consisting of DMSO and H2O (7:3, v/v). Upon addition of Ag+ ions, noticeable changes in absorption spectra occur, resulting in a visible color change from pale yellow to blue. Additionally, an enhanced emission intensity with wavelength at 523 nm, when excited at 410 nm. Notably, TZPYZ demonstrated exceptional selectivity for Ag+ ions over other metal cations, achieving a detection limit (LOD) of 10.6 × 10−9 M and 6.74 × 10−9 M and using the UV–visible & photoluminescent titration method. Interference studies indicated minimal disruption from other metal ions on emission at 523 nm, highlighting TZPYZ discerning capability for Ag+ ions. With a binding affinity of 3.622 × 10−11 M−1, TZPYZ proved effective in detecting Ag+ ions across various water samples, showcasing its practical utility. The mechanism of interaction between TZPYZ and Ag+ ions was investigated using various experimental techniques, including Job’s plot, Benesi-Hildebrand investigations, 1H NMR, and HRMS analysis. Test strips coated with TZPYZ showed selective detection of Ag+ ions, indicating its potential for on-site applications. Furthermore, DFT computations provided insights into the structural and electronic properties of TZPYZ and its complex with Ag+ ions, further elucidating the binding mechanism and stability of the complex. In addition, TZPYZ demonstrated compatibility with biological systems, as fluorescence imaging tests on MCF-7 breast cancer cells confirmed both its non-cytotoxic nature and its proficiency in detecting intracellular silver ions. Based on these findings, TZPYZ is highlighted as a highly sensitive and selective chemosensor for Ag+ ions, with promising applications in environmental analysis and bioimaging.

Exploring the electronic influence on coordination complexes formed from appended pyrrolidine azothioformamide ligands and copper(I) salts

Redox-active arylazothioformamide (ATF) ligands have seen attention through their unique coordination complexes formed with salts of late transition metals and their known ability to oxidatively dissolve zerovalent metals. When mixed with Cu(I) salts, ATF ligands form both 2:1 and 2:2 coordination complexes remaining neutral without undergoing any redox event. Herein, a series of para-substituted pyrrolidine-ATFs were synthesized, incorporating both electron-donating groups (i.e., -OMe and -Me) as well as electron-withdrawing groups (i.e., -CF3, and -CN). These ligands were then mixed with Cu(I) salts, including CuBr, CuI, and [(CH3CN)4Cu](BF4) to form coordination complexes. The resulting complexes underwent thorough characterization, with several producing X-ray quality crystals for detailed structural analysis. Both strong and weak intermolecular interactions were found through Hirshfeld surface analysis and the redox activity of the complexes was probed using cyclic voltammetry in the voltage range of -1.8 to 1.8 V. Through a UV–Vis titration study, the binding interactions between the ligand host and Cu(I) metal salt guest molecules were determined and ranged from 4,000 – 100,000 M-1. Computational modeling was employed to calculate the change in Gibbs free energy (ΔG) for the formation of the complexes, revealing the optimal orientations between the ligand and the metal. These studies have confirmed that para-substituted pyrrolidine-ATFs containing electron-donating groups exhibit a higher binding affinity towards Cu(I) metal salts compared to those with electron-withdrawing groups. With a thorough understanding of ATF-metal coordination, further ligand design can lead to exciting new catalysts and/or selective metal dissolution agents.

Impact of enniatins and beauvericin on lipid metabolism: Insights from a 3D HepaRG spheroid model

Emerging mycotoxins enniatins (ENNs) and beauvericin (BEA) pose potential health risks to humans through dietary exposure. However, research into their mechanisms of toxicity is limited, with a lack of comprehensive toxicological data. This study investigates from a hepatic lipid metabolism perspective, establishing a more precise and reliable 3D HepaRG hepatocyte spheroid model as an alternative for toxicity assessment. Utilizing physiological indices, histopathological analyses, lipidomics, and molecular docking techniques, it comprehensively elucidates the effects of ENNs and BEA on hepatic lipid homeostasis and their molecular toxicological mechanisms. Our findings indicate that ENNs and BEA impact cellular viability and biochemical functions, significantly altering lipid metabolism pathways, particularly those involving glycerophospholipids and sphingolipids. Molecular docking has demonstrated strong binding affinity of ENNs and BEA with key enzymes in lipid metabolism such as Peroxisome Proliferator-Activated Receptor α (PPARα) and Cytosolic Phospholipase A2 (cPLA2), revealing the mechanistic basis for their hepatotoxic effects and potential to impair liver function and human health. These insights enhance our understanding of the potential hepatotoxicity of such fungal toxins and lay a foundation for the assessment of their health risks.

Galangin attenuates chlorpyrifos-induced kidney injury by mitigating oxidative stress and inflammation and upregulating Nrf2 and farnesoid-X-receptor in rats

Chlorpyrifos (CPF) is a highly toxic commonly used pesticide and can seriously harm human health. This study assessed the potential of galangin (GAL), an antioxidant flavonoid, to attenuate oxidative stress, inflammation and kidney injury caused by CPF, emphasizing the role of farnesoid-x-receptor (FXR) and Nrf2. Rats were supplemented with CPF and GAL for 28 days. CPF increased serum creatinine, urea and Kim-1, provoked several tissue alterations, and increased kidney ROS, malondialdehyde (MDA), NF-κB p65, TNF-α, iNOS, and caspase-3. GAL effectively ameliorated serum kidney injury markers, ROS, MDA, and TNF-α, suppressed NF-κB p65, iNOS, and caspase-3, and enhanced antioxidants. GAL suppressed Keap1 and upregulated FXR, Nrf2, HO-1 and NQO-1 in CPF-administered rats. GAL exhibited binding affinity with Keap1, FXR, caspase-3, iNOS, HO-1, and NF-κB. In conclusion, GAL is effective in preventing CPF nephrotoxicity by attenuating oxidative stress and inflammation. This protection is linked to upregulation of antioxidants, Nrf2/HO-1 signaling and FXR.

Synthesis of pyrazole and pyrazoline derivatives of β-ionone: Exploring anti-inflammatory potential, cytotoxicity, and molecular docking insights

In the present paper, pyrazole and pyrazoline derivatives of β-ionone were synthesized. The protocol involved intramolecular oxidative C–H amination of hydrazone to yield corresponding pyrazole in moderate to good yields. Another methodology comprising of condensation of hydrazine hydrochloride with β-ionone in methanol leading to pyrazoline and its oxidative dehydrogenation using hypervalent iodine reagent to synthesize pyrazole is also achieved. One pot methodology for synthesis of pyrazole is also developed by refluxing the hydrazine hydrochloride with β-ionone in acetic acid. The structures of the synthesized compounds were elucidated using 1H NMR, 13C NMR, FTIR and mass spectrometry. All the pyrazole and pyrazoline derivatives were subjected to bovine serum albumin assay for in-vitro anti-inflammatory activity and all the compounds exhibited good to excellent activity. Compounds containing bromo and sulfonamide group exhibited inhibition rates of 87.36 % and 85.82 %, respectively, at a concentration of 0.5 mg/mL, surpassing the efficacy of the standard drug celecoxib (81.67 %). Further, cytotoxicity of the compounds was also evaluated against VERO cell line and all the compounds exhibited the cytotoxic values almost similar to the standard. Molecular docking was performed to study binding affinity of the potent compounds i. e bromo bearing pyrazole and sulfonamide bearing pyrazoline into the crystal structure of COX-II enzyme (PDB ID: 3LN1) at celecoxib binding site to determine the binding energy and interactions.

Elucidating Chiral Resolution of Aromatic Amino Acids Using Glycopeptide Selectors: A Combined Molecular Docking and Chromatographic Study.

An asymmetric synthesis is a favorable approach for obtaining enantiomerically pure substances, but racemic resolution remains an efficient strategy. This study aims to elucidate the chiral resolution of aromatic amino acids and their elution order using glycopeptides as chiral selectors through molecular docking analysis. Chiral separation experiments were conducted using Vancomycin as a chiral additive in the mobile phase (CMPA) at various concentrations, coupled with an achiral amino column as the stationary phase. The Autodock Vina 1.1.2 software was employed to perform molecular docking simulations between each enantiomer (ligand) and Vancomycin (receptor) to evaluate binding affinities, demonstrate enantiomeric resolution feasibility, and elucidate chiral recognition mechanisms. Utilizing Vancomycin as CMPA at a concentration of 1.5 mM enabled the separation of tryptophan enantiomers with a resolution of 3.98 and tyrosine enantiomers with a resolution of 2.97. However, a poor chiral resolution was observed for phenylalanine and phenylglycine. Molecular docking analysis was employed to elucidate the lack of separation and elution order for tryptophan and tyrosine enantiomers. By calculating the binding energy, docking results were found to be in good agreement with experimental findings, providing insights into the underlying mechanisms governing chiral recognition in this system and the interaction sites. This comprehensive approach clarifies the complex relationship between chiral discrimination and molecular architecture, offering valuable information for creating and improving chiral separation protocols.

Mechanisms of Selected Cassipourea Metabolites for Melasma Treatment: Network Pharmacology and Molecular Dynamics Study

Background Melasma is a common dyschromia, mainly found in women with darker skin types. Although asymptomatic, melasma significantly impacts patients’ quality of life. Due to this complex pathogenesis, melasma is difficult to treat. Plant and plant-derived products have been explored as alternatives for the treatment of melasma. Methods This study utilized network pharmacology coupled with molecular docking and molecular dynamics simulations to investigate the molecular mechanisms of three selected Cassipourea metabolites in the treatment of melasma. Results Of the 202 genes obtained from the 14 profiled metabolites, only PTGS2, TYR, ESR2, and ESR1 were common among metabolites and targets implicated in melasma. From this, The gene ontology highlighted the intracellular steroid hormone receptor, signalling pathway, macromolecular complex, and estrogen receptor activity as the top enriched functional annotations, while the KEGG pathway analysis identified five signalling pathways, from which the prolactin signalling pathway, endocrine resistance, and estrogen signalling pathway were implicated in the pathogenesis of melasma. These pathways were further connected by their linkage to ESR2 and ESR1., Of all Cassipourea metabolites and standards, with afzelechin having the highest docking score for both gens. Further binding interaction analysis showed that ESR2-bound tamoxifen had the highest binding free energy of -47.68 kcal/mol, however, among the interacting Cassipourea metabolites, sitosterol-glycoside exhibited the highest negative binding affinity for both ESR2 (-40.50 kcal/mol) and ESR1 (-78.97 kcal/mol) over 150 ns simulation, suggesting its potential as a dual modulator. Altogether, the metabolites presented remarkable binding stability and thermodynamic compactness with the apo-genes. Conclusion The finding that the selected Cassipourea metabolites are associated with the genes and enzymes implicated in melasma pathogenesis, together with their significant binding effects on the enriched genes, suggests their regulatory potential on the profiled targets and, consequently, in the treatment of melasma.

Structural identification, rheological properties and immunological receptor of a complex galacturonoglucan from fruits of Schisandra chinensis (Turcz.) Baill

A complex heteropolysaccharide SCP-2 named schisanan B (Mw = 1.005 × 105 g/mol) was obtained from water extracts of Schisandra chinensis fruits, and its planar structure was finally deduced as a galacturonoglucan by a combination of monosaccharide compositions, methylation analysis, partial acid hydrolysis, enzymatic hydrolysis and 1D/2D-nuclear magnetic resonance spectroscopy. The conformation of SCP-2 exhibited a globular shape with branching in ammonium formate aqueous solutions. The rheological properties of SCP-2 were investigated on concentrations, temperature, pH and salts. The in vitro immunomodulatory activity assay demonstrated that SCP-2 significantly enhanced the production of nitric oxide (NO) and stimulated the secretion of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in macrophages. Through a combination of high-resolution live-cell imaging, surface plasmon resonance, and molecular docking techniques, SCP-2 exhibited a strong binding affinity with the Toll-like receptor 4 (TLR4). Moreover, western blot analysis revealed that SCP-2 effectively induced downstream signaling proteins associated with TLR4 activation, thereby promoting macrophage activation. The evidence strongly indicates that TLR4 functions as a membrane protein target in the activation of macrophages and immune regulation induced by SCP-2.

In Silico and In Vivo Studies of β-Sitosterol Nanoparticles as a Potential Therapy for Isoprenaline-Induced Cognitive Impairment in Myocardial Infarction, Targeting Myeloperoxidase.

This study aimed to compare the effects of β-sitosterol nanoparticles (BETNs) and β-sitosterol (BET) on cognitive impairment, oxidative stress, and inflammation in a myocardial infarction (MI) rat model using in silico and in vivo methods. β-Sitosterol (BET) and myeloperoxidase (MPO) ligand-receptor binding affinities were evaluated using Autodock Vina for docking and Gromacs for dynamics simulations. BET nanoparticles, prepared via solvent evaporation, had their size confirmed by a nanoparticle analyzer. ISO-induced cognitive impairment in rats was assessed through Morris water maze and Cook's pole climbing tests. Oxidative stress, inflammation, and cardiac injury were evaluated by measuring GSH, SOD, MDA, MPO, CkMB, LDH, lipid profiles, and ECGs. Histopathology of the CA1 hippocampus and myocardial tissue was performed using H&E staining. In silico analyses revealed strong binding affinities between BET and MPO, suggesting BET's potential anti-inflammatory effect. BETN (119.6 ± 42.6 nm; PDI: 0.809) significantly improved MI-induced cognitive dysfunction in rats (p < 0.001 ***), increased hippocampal GSH (p < 0.01 **) and SOD (p < 0.01 **) levels, and decreased hippocampal MDA (p < 0.05 *) and MPO levels (p < 0.01 **). BETNs also elevated cardiac GSH (p < 0.01 **) and SOD (p < 0.01 **) levels and reduced cardiac MPO (p < 0.01 **), CkMB (p < 0.001 **) and LDH (p < 0.001 **) levels. It restored lipid profiles, normalized ECG patterns, and improved histology in the hippocampal CA1 region and myocardium. Compared with BET treatment, BETNs were more effective in improving cognitive impairment, oxidative damage, and inflammation in MI rats, suggesting its potential in treating cognitive dysfunction and associated pathological changes in MI.

Valorization of hydro-distillate of fruit peels of Citrus paradisi macfad. Cultivar. Foster: Chemical profiling, antioxidant evaluation and in vitro and in silico enzyme inhibition studies

The major commercial crops in Pakistan are citrus fruit trees, which are farmed extensively and serve as the country's principal source of foreign exchange. A local citrus plant, Citrus paradisi, variety Foster is famous for its valuable fruit and fruit juice, however, tons of peels of this fruit are thrown as waste, which otherwise can be utilized in formulating nutraceutical and cosmetics. In the present study, essential oil of fruit peels was obtained through hydro-distillation, which was then analyzed through GC-MS analysis and studied for its antioxidant and enzyme inhibition potential. GCMS analysis revealed the presence of several components; major were found to be limonene, α-terpineol, caryophyllene, δ-amorphene, elemol, γ-eudesoml, nootkatone and di-isooctyl phthalate. Although, the oil showed weak free radical inhibition, it was potentially active in CUPRAC, FRAP, phosphomolybdenum and metal chelating antioxidant assays. The oil also exhibited anti-glucosidase, anti-amylase activities and also exhibited potent inhibition of the enzyme tyrosinase, which makes it strong candidate for nutraceuticals and skin care products. The docking studies also substantiate our results and caryophyllene, γ-eudesoml and nootkatone showed good binding affinity α-glucosidase and α-amylase and all tested compounds showed the higher binding affinity towards the enzyme tyrosinase.

177Lu-labeling of nuclear localization sequence (NLS)-grafted HER2-receptor affine peptide

Tagging of cell permeable nuclear localization sequence (NLS) with receptor targeting peptide vectors is an attractive strategy for selectively targeted translocation of therapeutic cargoes. The present study aimed at grafting nuclear localization sequence (NLS) onto breast cancer targeting rL-A9 peptide. Molecular docking analysis revealed higher binding affinity of the peptide, DOTA-NLS-rL-A9 (−26.1 kJ/mol) towards HER2 receptor in comparison to DOTA-rL-A9 peptide (−22.2 kJ/mol). Confocal microscopy data suggested significantly enhanced cellular internalization of NLS-tagged peptide. The engineered HER2-selective, DOTA-NLS-rL-A9 peptide scaffold was radiolabeled with Lu-177 for intracellular delivery of the theranostic radionuclide into tumor cells. [177Lu]Lu-DOTA-NLS-rL-A9 exhibited significantly enhanced binding affinity (4.58 ± 1.77 nM) towards human breast carcinoma SKBR3 cells and cellular internalization (85 % at 24 h) compared to its original analog, [177Lu]Lu-DOTA-rL-A9. In vivo biodistribution studies showed consistent retention of [177Lu]Lu-DOTA-NLS-rL-A9 in the tumor with negligible washout of radioactivity (∼4.1 % ID/g at 48 h). Prolonged tumor activity with rapid off-target tissue clearance resulted in significantly high tumor-to-background ratios. The radiopeptide, [177Lu]Lu-DOTA-NLS-rL-A9 thus, being precisely confined into HER2-expressing tumor cells and exhibiting favourable pharmacokinetic features is an efficient candidate for further screening.