Evaluation of the IKKβ Binding of Indicaxanthin by Induced-Fit Docking, Binding Pose Metadynamics, and Molecular Dynamics

Optimizing 2-furylated imidazole π-bridges for NIR lipid droplet imaging

Lipid droplets (LDs) are globular biological organelles found in the human body, essential for lipid storage, homeostasis, energy reserve, cellular stress response, membrane biogenesis, and cellular signaling. Dysregulated accumulation of LDs leads to various diseases, including breast and liver cancers. Therefore, the development of diagnostic tools for monitoring LDs using suitable probes for bio-imaging applications is imperative. However, identifying promising probes with near-infrared emission characteristics is still a challenging and intriguing task, requiring extensive exploration of the structure-emission property relationship to design efficient probes for LDs. In this context, we envision the impact of 2-furylated imidazole as a π-bridge and have designed nine LD probes by substituting it with electron-releasing groups like CH3, NH2, NH(CH3), and N(CH3)2 at the 3rd and 4th positions via DFT, TD-DFT, FMO, ESP, NCI, and QTAIM analyses. Our results demonstrate that LDP7 with NH(CH3) at the 3rd position is the most promising molecule, exhibiting the highest emission maxima (772.02 nm) with a lower HOMO-LUMO gap, suggesting its suitability for a range of biomedical applications. An enhancement of ∼200 nm is achieved through tailoring the molecular structure using the designed 2-furylated imidazole-derived π-bridge. ADMET and molecular docking analysis followed by molecular dynamics simulations with the human pyruvate kinase protein reveal these LDPs' bioavailability, binding ability and their stability towards their bio-imaging applications. In summary, our study offers valuable insights to aid researchers in developing and refining various π-linkers for lipid droplet bio-imaging applications.

Active and machine learning-enhanced discovery of new FGFR3 inhibitor, Rhapontin, through virtual screening of receptor structures and anti-cancer activity assessment

Introduction: This study bridges traditional remedies and modern pharmacology by exploring the synergy between natural compounds and Ceritinib in treating Non-Small Cell Lung Cancer (NSCLC), aiming to enhance efficacy and reduce toxicities. Methods: Using a combined approach of computational analysis, machine learning, and experimental procedures, we identified and analyzed PD173074, Isoquercitrin, and Rhapontin as potential inhibitors of fibroblast growth factor receptor 3 (FGFR3). Machine learning algorithms guided the initial selection, followed by Quantitative Structure-Activity Relationship (QSAR) modeling and molecular dynamics simulations to evaluate the interaction dynamics and stability of Rhapontin. Physicochemical assessments further verified its drug-like properties and specificity. Results: Our experiments demonstrate that Rhapontin, when combined with Ceritinib, significantly suppresses tumor activity in NSCLC while sparing healthy cells. The molecular simulations and physicochemical evaluations confirm Rhapontin's stability and favorable interaction with FGFR3, highlighting its potential as an effective adjunct in NSCLC therapy. Discussion: The integration of natural compounds with established cancer therapies offers a promising avenue for enhancing treatment outcomes in NSCLC. By combining the ancient wisdom of natural remedies with the precision of modern science, this study contributes to evolving cancer treatment paradigms, potentially mitigating the side effects associated with current therapies.

In-silico lead identification of the pan-mutant IDH1 and IDH2 inhibitors to target glioblastoma

Glioblastoma (GBM) is an aggressive malignant type of brain tumor. Targeting one single intracellular pathway might not alleviate the disease, rather it activates the other molecular pathways that lead to the worsening of the disease condition. Therefore, in this study, we attempted to target both isocitrate dehydrogenase 1 (IDH1) and IDH2, which are one of the most commonly mutated proteins in GBM and other cancer types. Here, standard precision and extra precision docking, IFD, MM-GBSA, QikProp, and molecular dynamics (MD) simulation were performed to identify the potential dual inhibitor for IDH1 and IDH2 from the enamine database containing 59,161 ligands. Upon docking the ligands with IDH1 (PDB: 6VEI) and IDH2 (PDB: 6VFZ), the top eight ligands were selected, based on the XP Glide score. These ligands produced favourable MMGBSA scores and ADME characteristics. Finally, the top four ligands 12953, 44825, 51295, and 53210 were subjected to MD analysis. Interestingly, 53210 showed maximum interaction with Gln 277 for 99% in IDH1 and Gln 316 for 100% in IDH2, which are the crucial amino acids for the inhibitory function of IDH1 and IDH2 to target GBM. Therefore, the present study attempts to identify the novel molecules which could possess a pan-inhibitory action on both IDH1 and IDH that could be crucial in the management of GBM. Yet further evaluation involving in vitro and in vivo studies is warranted to support the data in our current study.Communicated by Ramaswamy H. Sarma.

A theoretical study on radical scavenging activity of phenolic derivatives naturally found within Alternaria alternata extract

The increasing oxidative stress demands potential chemical compounds derived from natural resources with good antioxidant activity to overcome adverse health issues. In this context, we investigated the antioxidant properties of four dibenzopyrone phenolic compounds obtained from the endophytic fungus Alternaria alternata: altenusin, altenusin B, alterlactone, and dehydroaltenusin using DFT calculations. Our investigation focused on understanding the structure-antioxidant property relationship. It delved into probing the activity by modelling the antioxidant mechanisms. The computed transition states and thermochemical parameters, along with the structural attributes, indicate that altenusin B has good antioxidant efficacy among the four compounds, and it follows the HAT mechanism in an aqueous phase. Remarkably, our findings indicate that altenusin B exhibits potent HOO˙ radical scavenging properties, characterized by the computed high rate constant. The molecular docking studies of these compounds with the pro-oxidant enzyme xanthine oxidase (XO) gave insights into the binding modes of the compounds in the protein environment. Furthermore, molecular dynamics (MD) simulations were employed to study the interaction and stability of the compounds inside the XO enzyme. Our exploration sheds light on the radical scavenging potential of the -OH sites and the underlying antioxidant mechanisms that underpin the compounds' effective antioxidant potential.

Avanafil mediated dual inhibition of IKKβ and TNFR1 in an experimental paradigm of Alzheimer's disease: in silico and in vivo approach

In Alzheimer's disease pathology, inhibitors of nuclear factor kappa-β kinase subunit β (IKKB) and Tumor necrosis factor receptor 1 (TNFR1) signaling are linked to neuroinflammation-mediated cognitive decline. We explored the role of a phosphodiesterase 5 inhibitor (PDE5I) with dual antagonistic action on IKKB and TNFR1 to inhibit nuclear factor kappa B (NF-kB) and curb neuroinflammation. In the in silico approach, the FDA-approved Zinc 15 library was docked with IKKB and TNFR1. The top compound with dual antagonistic action on IKKB and TNFR1 was selected based on bonding and non-bonding interactions. Further, induced fit docking (IFD), molecular mechanics-generalized Born and surface area (MMGBSA), and molecular dynamic studies were carried out and evaluated. Lipopolysaccharide (LPS) administration caused a neuroinflammation-mediated cognitive decline in mice. Two doses of avanafil were administered for 28 days while LPS was administered for 10 days. Morris water maze (MWM) along with the passive avoidance test (PAT) were carried out. Concurrently brain levels of inflammatory markers, oxidative parameters, amyloid beta (Aβ), IKKB and NF-kB levels were estimated. Avanafil produced good IKKB and TNFR1 binding ability. It interacted with crucial inhibitory amino acids of IKKB and TNFR1. MD analysis predicted good stability of avanafil with TNFR1 and IKKB. Avanafil 6 mg/kg could significantly improve performance in MWM, PAT and oxidative parameters and reduce Aβ levels and inflammatory markers. As compared to avanafil 3 mg/kg, 6 mg/kg dose was found to exert better efficacy against elevated Aβ , neuroinflammatory cytokines and oxidative markers while improving behavioural parameters.Communicated by Ramaswamy H. Sarma.

Virtual Screening Strategy and In Vitro Tests to Identify New Inhibitors of the Immunoproteasome

Immunoproteasome inhibition is a promising strategy for the treatment of hematological malignancies, autoimmune diseases, and inflammatory diseases. The design of non-covalent inhibitors of the immunoproteasome β1i/β5i catalytic subunits could be a novel approach to avoid the drawbacks of the known covalent inhibitors, such as toxicity due to off-target binding. In this work, we report the biological evaluation of thirty-four compounds selected from a commercially available collection. These hit compounds are the outcomes of a virtual screening strategy including a dynamic pharmacophore modeling approach onto the β1i subunit and a pharmacophore/docking approach onto the β5i subunit. The computational studies were first followed by in vitro enzymatic assays at 100 μM. Only compounds capable of inhibiting the enzymatic activity by more than 50% were characterized in detail using Tian continuous assays, determining the dissociation constant (K_i) of the non-covalent complex where K_i is also the measure of the binding affinity. Seven out of thirty-four hits showed to inhibit β1i and/or β5i subunit. Compound 3 is the most active on the β1i subunit with K_i = 11.84 ± 1.63 µM, and compound 17 showed K_i = 12.50 ± 0.77 µM on the β5i subunit. Compound 2 showed inhibitory activity on both subunits (K_i = 12.53 ± 0.18 and K_i = 31.95 ± 0.81 on the β1i subunit and β5i subunit, respectively). The induced fit docking analysis revealed interactions with Thr1 and Phe31 of β1i subunit and that represent new key residues as reported in our previous work. Onto β5i subunit, it interacts with the key residues Thr1, Thr21, and Tyr169. This last hit compound identified represents an interesting starting point for further optimization of β1i/β5i dual inhibitors of the immunoproteasome.

Investigating the Inhibition of FTSJ1, a Tryptophan tRNA-Specific 2'-O-Methyltransferase by NV TRIDs, as a Mechanism of Readthrough in Nonsense Mutated CFTR

Cystic Fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene, coding for the CFTR chloride channel. About 10% of the CFTR gene mutations are "stop" mutations that generate a premature termination codon (PTC), thus synthesizing a truncated CFTR protein. A way to bypass PTC relies on ribosome readthrough, which is the ribosome's capacity to skip a PTC, thus generating a full-length protein. "TRIDs" are molecules exerting ribosome readthrough; for some, the mechanism of action is still under debate. We investigate a possible mechanism of action (MOA) by which our recently synthesized TRIDs, namely NV848, NV914, and NV930, could exert their readthrough activity by in silico analysis and in vitro studies. Our results suggest a likely inhibition of FTSJ1, a tryptophan tRNA-specific 2'-O-methyltransferase.

AI-driven drug repurposing and binding pose meta dynamics identifies novel targets for Monkeypox virus

Monkeypox virus (MPXV) was confirmed in May 2022 and designated a global health emergency by WHO in July 2022. MPX virions are big, enclosed, brick-shaped, and contain a linear, double-stranded DNA genome as well as enzymes. MPXV particles bind to the host cell membrane via a variety of viral-host protein interactions. As a result, the wrapped structure is a potential therapeutic target. DeepRepurpose, an artificial intelligence-based compound-viral proteins interaction framework, was used via a transfer learning setting to prioritize a set of FDA approved and investigational drugs which can potentially inhibit MPXV viral proteins. To filter and narrow down the lead compounds from curated collections of pharmaceutical compounds, we used a rigorous computational framework that included homology modeling, molecular docking, dynamic simulations, binding free energy calculations, and binding pose metadynamics. We identified Elvitegravir as a potential inhibitor of MPXV virus using our comprehensive pipeline.

Virtual screening and activity evaluation of human uric acid transporter 1 (hURAT1) inhibitors

Hyperuricemia is a disease caused by disorder of purine metabolism, mainly due to insufficient renal excretion of uric acid. Urate transporter 1 (URAT1) is the most widely studied target of urate transporters, and used for uric acid (UA) reabsorption. This study used the AlphaFold2 algorithm to predict the structure of URAT1. Virtual screening and biological evaluation were used to discover novel URAT1 inhibitors that target the critical amino acids. Seven compounds were screened from the T2220 database and validated as URAT1 inhibitors by cell biology experiments. The IC50 values of benbromarone, NP023335, TN1148, and TN1008 were 6.878, 18.46, 24.64, and 53.04 μM, respectively. Molecular dynamics simulation was used to investigate the binding mechanism of URAT1 to NP023335, which forms stable contact with Ser35, Phe365, and Arg477. These interactions are essential for maintaining the biological activity of NP023335. The three compounds' pharmacokinetic characteristics were predicted, and NP023335's properties matched those of an empirical medication with the benefits of high solubility, low cardiotoxicity, good membrane permeability, and oral absorption. The natural product NP023335 will serve as a promising hit compound for facilitating the further design of novel URAT1 inhibitors.

Virtual structure-based docking and molecular dynamics of FDA-approved drugs for the identification of potential IKKB inhibitors possessing dopaminergic activity in Alzheimer’s disease

In Alzheimer's disease (AD), neuroinflammation is detrimental in causing neurodegeneration. In the central nervous system, inhibitor of nuclear factor kappa B kinase subunit beta (IKK2/IKKβ/IKKB/IKBKB) signaling is linked to neuroinflammation-mediated learning and memory deficits through canonical pathway, while dopamine agonists have been known to reverse such effects. Our in silico analysis predicted if dopaminergic agonists could have IKKB inhibitory actions, to ameliorate neuroinflammation-associated learning and memory deficits. Here, the FDA-approved Zinc 15 database was screened with IKKB (PDB ID 4KIK). Potential molecules with IKKB inhibition were identified through docking, which also possessed dopaminergic activity. Molecular mechanics—generalized Born and surface area (MMGBSA), induced fit docking (IFD) and molecular dynamic (MD) studies of 100 ns simulation time were done. Apomorphine and rotigotine showed greater non-bonding and bonding interactions with amino acids of IKKB as compared to Aripiprazole in docking studies. The IFD studies predicted improved interactions with IKKB. MMGBSA scores indicated that the complex binding free energies were favorable, and MD studies showed an acceptable root mean square deviation between protein and ligands. The protein–ligand interactions showed hydrogen bonds, water and salt bridges necessary for IKKB inhibition, as well as solvent system stability. On the protein–ligand contact map, the varying color band intensities represented the ligand’s ability to bind with amino acids. Dopamine agonists apomorphine, rotigotine, and aripiprazole were predicted to bind and inhibit IKKB in in silico system.

Graphical Abstract

Exploring new catechin derivatives as SARS-CoV-2 Mpro inhibitors from tea by molecular networking, surface plasma resonance, enzyme inhibition, induced fit docking, and metadynamics simulations

SARS-CoV-2 M^pro (Mpro) is the critical cysteine protease in coronavirus viral replication. Tea polyphenols are effective M^pro inhibitors. Therefore, we aim to isolate and synthesize more novel tea polyphenols from Zhenghedabai (ZHDB) white tea methanol-water (MW) extracts that might inhibit COVID-19. Through molecular networking, 33 compounds were identified and divided into 5 clusters. Further, natural products molecular network (MN) analysis showed that MN1 has new phenylpropanoid-substituted ester-catechin (PSEC), and MN5 has the important basic compound type hydroxycinnamoylcatechins (HCCs). Thus, a new PSEC (1, PSEC636) was isolated, which can be further detected in 14 green tea samples. A series of HCCs were synthesized (2-6), including three new acetylated HCCs (3-5). Then we used surface plasmon resonance (SPR) to analyze the equilibrium dissociation constants (K_D) for the interaction of 12 catechins and M^pro. The K_D values of PSEC636 (1), EGC-C (2), and EC-CDA (3) were 2.25, 2.81, and 2.44 μM, respectively. Moreover, compounds 1, 2, and 3 showed the potential M^pro inhibition with IC₅₀ 5.95 ± 0.17, 9.09 ± 0.22, and 23.10 ± 0.69 μM, respectively. Further, we used induced fit docking (IFD), binding pose metadynamics (BPMD), and molecular dynamics (MD) to explore the stable binding pose of M^pro-1, showing that 1 could tightly bond with the amino acid residues THR²⁶, HIS⁴¹, CYS⁴⁴, TYR⁵⁴, GLU¹⁶⁶, and ASP¹⁸⁷. The computer modeling studies reveal that the ester, acetyl, and pyrogallol groups could improve inhibitory activity. Our research suggests that these catechins are effective M^pro inhibitors, and might be developed as therapeutics against COVID-19.

Redox Properties, Bioactivity and Health Effects of Indicaxanthin, a Bioavailable Phytochemical from Opuntia ficus indica, L.: A Critical Review of Accumulated Evidence and Perspectives

Phytochemicals from plant foods are considered essential to human health. Known for their role in the adaptation of plants to their environment, these compounds can induce adaptive responses in cells, many of which are directed at maintaining the redox tone. Indicaxanthin is a long-known betalain pigment found in the genus Opuntia of cactus pear and highly concentrated in the edible fruits of O. ficus indica, L. whose bioactivity has been overlooked until recently. This review summarizes studies conducted so far in vitro and in vivo, most of which have been performed in our laboratory. The chemical and physicochemical characteristics of Indicaxanthin are reflected in the molecule's reducing properties and antioxidant effects and help explain its ability to interact with membranes, modulate redox-regulated cellular pathways, and possibly bind to protein molecules. Measurement of bioavailability in volunteers has been key to exploring its bioactivity; amounts consistent with dietary intake, or plasma concentration after dietary consumption of cactus pear fruit, have been used in experimental setups mimicking physiological or pathophysiological conditions, in cells and in animals, finally suggesting pharmacological potential and relevance of Indicaxanthin as a nutraceutical. In reporting experimental results, this review also aimed to raise questions and seek insights for further basic research and health promotion applications.

Deciphering the Potential of Pre and Pro-Vitamin D of Mushrooms against Mpro and PLpro Proteases of COVID-19: An In Silico Approach

Vitamin D's role in combating the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), the virus causing COVID-19, has been established in unveiling viable inhibitors of COVID-19. The current study investigated the role of pre and pro-vitamin D bioactives from edible mushrooms against Mpro and PLpro proteases of SARS-CoV-2 by computational experiments. The bioactives of mushrooms, specifically ergosterol (provitamin D2), 7-dehydrocholesterol (provitamin-D3), 22,23-dihydroergocalciferol (provitamin-D4), cholecalciferol (vitamin-D3), and ergocalciferol (vitamin D2) were screened against Mpro and PLpro. Molecular docking analyses of the generated bioactive protease complexes unravelled the differential docking energies, which ranged from -7.5 kcal/mol to -4.5 kcal/mol. Ergosterol exhibited the lowest binding energy (-7.5 kcal/mol) against Mpro and PLpro (-5.9 kcal/mol). The Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) and MD simulation analyses indicated that the generated complexes were stable, thus affirming the putative binding of the bioactives to viral proteases. Considering the pivotal role of vitamin D bioactives, their direct interactions against SARS-CoV-2 proteases highlight the promising role of bioactives present in mushrooms as potent nutraceuticals against COVID-19.

MDO: A Computational Protocol for Prediction of Flexible Enzyme-Ligand Binding Mode

AIM

Developing a method for use in computer aided drug design Background: Predicting the structure of enzyme-ligand binding mode is essential for understanding the properties, functions, and mechanisms of the bio-complex, but is rather difficult due to the enormous sampling space involved.

OBJECTIVE

Accurate prediction of enzyme-ligand binding mode conformation.

METHOD

A new computational protocol, MDO, is proposed for finding the structure of ligand binding pose. MDO consists of sampling enzyme sidechain conformations via molecular dynamics simulation of enzyme-ligand system and clustering of the enzyme configurations, sampling ligand binding poses via molecular docking and clustering of the ligand conformations, and the optimal ligand binding pose prediction via geometry optimization and ranking by the ONIOM method. MDO is tested on 15 enzyme-ligand complexes with known accurate structures.

RESULTS

The success rate of MDO predictions, with RMSD < 2 Å, is 67%, substantially higher than the 40% success rate of conventional methods. The MDO success rate can be increased to 83% if the ONIOM calculations are applied only for the starting poses with ligands inside the binding cavities.

CONCLUSION

The MDO protocol provides high quality enzyme-ligand binding mode prediction with reasonable computational cost. The MDO protocol is recommended for use in the structure-based drug design.

A Computational Approach to Elucidate the Interactions of Chemicals From Artemisia annua Targeted Toward SARS-CoV-2 Main Protease Inhibition for COVID-19 Treatment

The inhibitory potential of Artemisia annua, a well-known antimalarial herb, against several viruses, including the coronavirus, is increasingly gaining recognition. The plant extract has shown significant activity against both the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and the novel SARS-CoV-2 that is currently ravaging the world. It is therefore necessary to evaluate individual chemicals of the plant for inhibitory potential against SARS-CoV-2 for the purpose of designing drugs for the treatment of COVID-19. In this study, we employed computational techniques comprising molecular docking, binding free energy calculations, pharmacophore modeling, induced-fit docking, molecular dynamics simulation, and ADMET predictions to identify potential inhibitors of the SARS-CoV-2 main protease (M^pro) from 168 bioactive compounds of Artemisia annua. Rhamnocitrin, isokaempferide, kaempferol, quercimeritrin, apigenin, penduletin, isoquercitrin, astragalin, luteolin-7-glucoside, and isorhamnetin were ranked the highest, with docking scores ranging from −7.84 to −7.15 kcal/mol compared with the −6.59 kcal/mol demonstrated by the standard ligand. Rhamnocitrin, Isokaempferide, and kaempferol, like the standard ligand, interacted with important active site amino acid residues like HIS 41, CYS 145, ASN 142, and GLU 166, among others. Rhamnocitrin demonstrated good stability in the active site of the protein as there were no significant conformational changes during the simulation process. These compounds also possess acceptable druglike properties and a good safety profile. Hence, they could be considered for experimental studies and further development of drugs against COVID-19.

Synthesis, Screening and Characterization of Novel Potent Arp2/3 Inhibitory Compounds Analogous to CK-666

Branched actin networks polymerized by the Actin-related protein 2 and 3 (Arp2/3) complex play key roles in force generation and membrane remodeling. These networks are particularly important for cell migration, where they drive membrane protrusions of lamellipodia. Several Arp2/3 inhibitory compounds have been identified. Among them, the most widely used is CK-666 (2-Fluoro-N-[2-(2-methyl-1H-indol-3-yl)ethyl]-benzamide), whose mode of action is to prevent Arp2/3 from reaching its active conformation. Here 74 compounds structurally related to CK-666 were screened using a variety of assays. The primary screen involved EdU (5-ethynyl-2′-deoxyuridine) incorporation in untransformed MCF10A cells. The resulting nine positive hits were all blocking lamellipodial protrusions and cell migration in B16-F1 melanoma cells in secondary screens, showing that cell cycle progression can be a useful read-out of Arp2/3 activity. Selected compounds were also characterized on sea urchin embryos, where Arp2/3 inhibition yields specific phenotypes such as the lack of triradiate spicules and inhibition of archenteron elongation. Several compounds were filtered out due to their toxicity in cell cultures or on sea urchin development. Two CK-666 analogs, 59 (N-{2-[5-(Benzyloxy)-2-methyl-1H-indol-3-yl] ethyl}-3-bromobenzamide) and 69 (2,4-Dichloro-N-[2-(7-chloro-2-methyl-1H-indol-3-yl) ethyl]-5-[(dimethylamino) sulfonyl] benzamide), were active in all assays and significantly more efficient in vivo than CK-666. These best hits with increased in vivo potency were, however, slightly less efficient in vitro than CK-666 in the classical pyrene-actin assay. Induced-fit docking of selected compounds and their possible metabolites revealed interaction with Arp2/3 that suppresses Arp2/3 activation. The data obtained in our screening validated the applicability of original assays for Arp2/3 activity. Several previously unexplored CK-666 structural analogs were found to suppress Arp2/3 activation, and two of them were identified as Arp2/3 inhibitors with improved in vivo efficiency.

Design, Semisynthesis, and Estrogenic Activity of Lignan Derivatives from Natural Dibenzylbutyrolactones

Based on molecular docking studies on the ERα, a series of lignan derivatives (3–16) were designed and semisynthesized from the natural dibenzylbutyrolactones bursehernin (1) and matairesinol dimethyl ether (2). To examine their estrogenic and antiestrogenic potencies, the effects of these compounds on estrogen receptor element (ERE)-driven reporter gene expression and viability in human ER+ breast cancer cells were evaluated. Lignan compounds induced ERE-driven reporter gene expression with very low potency as compared with the pure agonist E2. However, coincubation of 5 μM of lignan derivatives 1, 3, 4, 7, 8, 9, 11, 13, and 14 with increasing concentrations of E2 (from 0.01 pM to 1 nM) reduced both the potency and efficacy of pure agonists. The binding to the rhERα-LBD was validated by TR-FRET competitive binding assay and lignans bound to the rhERα with IC₅₀ values from 0.16 μM (compound 14) to 6 μM (compound 4). Induced fit docking (IFD) and molecular dynamics (MD) simulations for compound 14 were carried out to further investigate the binding mode interactions. Finally, the in silico ADME predictions indicated that the most potent lignan derivatives exhibited good drug-likeness.

In Silico Design, Synthesis, and Biological Evaluation of Anticancer Arylsulfonamide Endowed with Anti-Telomerase Activity

Telomerase, a reverse transcriptase enzyme involved in DNA synthesis, has a tangible role in tumor progression. Several studies have evidenced telomerase as a promising target for developing cancer therapeutics. The main reason is due to the overexpression of telomerase in cancer cells (85–90%) compared with normal cells where it is almost unexpressed. In this paper, we used a structure-based approach to design potential inhibitors of the telomerase active site. The MYSHAPE (Molecular dYnamics SHared PharmacophorE) approach and docking were used to screen an in-house library of 126 arylsulfonamide derivatives. Promising compounds were synthesized using classical and green methods. Compound 2C revealed an interesting IC₅₀ (33 ± 4 µM) against the K-562 cell line compared with the known telomerase inhibitor BIBR1532 IC₅₀ (208 ± 11 µM) with an SI ~10 compared to the BALB/3-T3 cell line. A 100 ns MD simulation of 2C in the telomerase active site evidenced Phe494 as the key residue as well as in BIBR1532. Each moiety of compound 2C was involved in key interactions with some residues of the active site: Arg557, Ile550, and Gly553. Compound 2C, as an arylsulfonamide derivative, is an interesting hit compound that deserves further investigation in terms of optimization of its structure to obtain more active telomerase inhibitors

Indicaxanthin from Opuntia ficus-indica Fruit Ameliorates Glucose Dysmetabolism and Counteracts Insulin Resistance in High-Fat-Diet-Fed Mice

Obesity-related dysmetabolic conditions are amongst the most common causes of death globally. Indicaxanthin, a bioavailable betalain pigment from Opuntia ficus-indica fruit, has been demonstrated to modulate redox-dependent signalling pathways, exerting significant anti-oxidative and anti-inflammatory effects in vitro and in vivo. In light of the strict interconnections between inflammation, oxidative stress and insulin resistance (IR), a nutritionally relevant dose of indicaxanthin has been evaluated in a high-fat diet (HFD) model of obesity-related IR. To this end, biochemical and histological analysis, oxidative stress and inflammation evaluations in liver and adipose tissue were carried out. Our results showed that indicaxanthin treatment significantly reduced body weight, daily food intake and visceral fat mass. Moreover, indicaxanthin administration induced remarkable, beneficial effects on HFD-induced glucose dysmetabolism, reducing fasting glycaemia and insulinaemia, improving glucose and insulin tolerance and restoring the HOMA index to physiological values. These effects were associated with a reduction in hepatic and adipose tissue oxidative stress and inflammation. A decrease in RONS, malondialdehyde and NO levels, in TNF-α, CCL-2 and F4-80 gene expression, in p65, p-JNK, COX-2 and i-NOS protein levels, in crown-like structures and hepatic inflammatory foci was, indeed, observed. The current findings encourage further clinical studies to confirm the effectiveness of indicaxanthin to prevent and treat obesity-related dysmetabolic conditions.