Discovery of novel IDO1/TDO2 dual inhibitors: a consensus Virtual screening approach with molecular dynamics simulations, and binding free energy analysis.

The pursuit of effective cancer immunotherapy drugs remains challenging, with overexpression of indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase 2 (TDO2) allowing cancer cells to evade immune attacks. While several IDO1 inhibitors have undergone clinical testing, only three dual IDO1/TDO2 inhibitors have reached human trials. Hence, this study focuses on identifying novel IDO1/TDO2 dual inhibitors through consensus structure-based virtual screening (SBVS). ZINC15 natural products library was refined based on molecular descriptors, and the selected compounds were docked to the holo form IDO1 and TDO2 using two different software programs and ranked according to their consensus docking scores. The top-scoring compounds underwent in silico evaluations for pharmacokinetics, toxicity, CYP3A4 affinity, molecular dynamics (MD) simulations, and MM-GBSA binding free energy calculations. Five compounds (ZINC00000079405/10, ZINC00004028612/11, ZINC00013380497/12, ZINC00014613023/13, and ZINC00103579819/14) were identified as potential IDO1/TDO2 dual inhibitors due to their high consensus docking scores, key residue interactions with the enzymes, favorable pharmacokinetics, and avoidance of CYP3A4 binding. MD simulations of the top three hits with IDO1 indicated conformational changes and compactness, while MM-GBSA analysis revealed strong binding free energy for compounds 10 (ΔG: -20.13 kcal/mol) and 11 (ΔG: -16.22 kcal/mol). These virtual hits signify a promising initial step in identifying candidates as supplementary therapeutics to immune checkpoint inhibitors in cancer treatment. Their potential to deliver potent dual inhibition of IDO1/TDO2, along with safety and favorable pharmacokinetics, makes them compelling. Validation through in vitro and in vivo assays should be conducted to confirm their activity, selectivity, and preclinical potential as holo IDO1/TDO2 dual inhibitors.Communicated by Ramaswamy H. Sarma.

In silico investigation of cholesterol-lowering drugs to find potential inhibitors of dehydrosqualene synthase in Staphylococcus aureus.

Staphylococcus aureus is a lethal pathogen that can cause various bacterial infections. This study targets the CrtM enzyme of S. aureus, which is crucial for synthesizing golden carotenoid pigment: staphyloxanthin, which provides anti-oxidant activity to this bacterium for combating antimicrobial resistance inside the host cell. The present investigation quests for human SQS inhibitors against the CrtM enzyme by employing structure-based drug design approaches including induced fit docking (IFD), molecular dynamic (MD) simulations, and binding free energy calculations. Depending upon the docking scores, two compounds, lapaquistat acetate and squalestatin analog 20, were identified as the lead molecules exhibit higher affinity toward the CrtM enzyme. These docked complexes were further subjected to 100 ns MD simulation and several thermodynamics parameters were analyzed. Further, the binding free energies (ΔG) were calculated for each simulated protein-ligand complex to study the stability of molecular contacts using the MM-GBSA approach. Pre-ADMET analysis was conducted for systematic evaluation of physicochemical and medicinal chemistry properties of these compounds. The above study suggested that lapaquistat acetate and squalestatin analog 20 can be selected as potential lead candidates with promising binding affinity for the S. aureus CrtM enzyme. This study might provide insights into the discovery of potential drug candidates for S. aureus with a high therapeutic index. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03862-y.

The efficacy of Linum usitatissimum seeds to inhibit estrogen receptor as a natural therapy for PCOS: An in silico and in vitro analysis.

Polycystic ovarian syndrome (PCOS) is an endocrinological disorder aroused due to hormonal disturbances. It is characterized by anovulation due to an excess of androgen and estrogen hormones, thus leading to the formation of multiple cysts, imposing life-threatening conditions. This manuscript aimed to introduce a natural estrogen receptor (ESR) inhibitors that can provide protection against PCOS. The computational analysis of Linum usitatissimum seeds  compounds against ESR alpha receptor was performed, and the binding affinities of the ligand compounds and receptor proteins were scrutinized. Nine lignin compounds were docked, and the results were compared with that of reference estrogen receptor inhibitors, clomiphene, and tamoxifen. The binding affinity scores for pinoresinol, lariciresinol, secoisolariciresinol, and matairesinol were -10.67, -10.66, -10.91, and -10.60 kcal mol-1 , respectively. These were comparable to the binding affinity score of reference compounds -11.406 kcal mol-1 for clomiphene and -10.666 kcal mol-1 for tamoxifen. Prime MM-GBSA studies showcased that Linum usitatissimum seeds compounds exhibit significant efficacy and efficiency towards receptor protein. Moreover, MD-simulation studies were performed and the results depict that the lignin compounds form stable complexes at 300 K throughout the simulation time. For further clarity, in-vitro experiments were carried out. The results exhibit the decline in cell proliferation in a concentration-dependent manner by extract 1 (ethyl acetate) EX1 and extract 2 (petroleum ether) EX2. Hence, providing evidence regarding the anti-estrogenic activity of the sample extracts. Collectively, these results showed that flax seed can reduce the levels of estrogen, which can induce ovulation and prevent cyst formation, and ultimately can provide protection against PCOS.

Integrated computational approach identifies potential inhibitors of ASK1-(JNK/P38) interaction signaling: new insights into cancer therapeutics.

Cancers are characterized by the aberrant expression of certain genes that trigger a cascade of molecular events that culminate in dysregulated cell division. Consequently, the inhibition of the products of these expressedgenes has emerged as a rational approach in cancer therapy. The apoptosis signal-regulating kinase 1 (ASK1) protein, encoded by the mitogen-activated protein kinase kinase kinase 5 (MAP3K5) gene, plays pertinent roles in the mediation of cell death induced by stress and inflammation, andis often found at elevated levels in cancer. Consequently, it has emerged as a molecular target for the development of potential chemotherapeutics through identification of selective inhibitors. However, there is still dearth of ASK1 inhibitors in clinical use. Hence, molecular modelling approaches were employed in this study to discover potential ASK1 inhibitors from phytochemicals. Twenty-five phytocompounds from four medicinal plants were tested for their inhibitory prowess via molecular docking. Interestingly, all the compounds exhibited promising inhibitory potentials for ASK1. However, further subjection to filtering procedures via different pipelines including drug-likeness evaluation, pharmacokinetics screening, toxicity profiling, and better affinities compared to the approved inhibitor resulted in three hit compounds namely ellagic acid, luteolin, and kaempferol with suitable properties. Profiling of the interactions formed between the hit\compounds and the targets revealed several interactions that were not present in that of the approved inhibitor, while molecular dynamics (MD) simulation revealed the complexes formed as stable. Conclusively, this study identified three compounds with ASK1 inhibitory potentials that are worthy of further exploration in in vitro and in vivo studies.Communicated by Ramaswamy H. Sarma.

The anticancer potential of chemical constituents of Moringa oleifera targeting CDK-2 inhibition in estrogen receptor positive breast cancer using in-silico and in vitro approches.

Most of the breast cancers are estrogen receptor-positive recurring with a steady rate of up to 20 years dysregulating the normal cell cycle. Dinaciclib is still in clinical trials and considered as a research drug against such cancers targeting CDK2.The major goal of this study was to identify the potential inhibitors of CDK-2 present in Moringa oleifera for treating hormonal receptor positive breast cancers. For this purpose, in silico techniques; molecular docking, MM-GBSA and molecular dynamics simulations were employed to screen Moringa oleifera compounds and their anticancer potential was determined against CDK-2 protein targets. Among 36 compounds of Moringa oleifera reported in literature, chlorogenic acid (1), quercetin (2), ellagic acid (3), niazirin (4), and kaempferol (5) showed good affinity with the target. The interaction of the compounds was visualized using PYMOL software. The profiles of absorption, distribution, metabolism, excretion (ADME) and toxicity were determined using SWISS and ProTox II webservers. The MTT assay was performed in-vitro using MCF-7 cancer cell lines to validate the anticancer potential of Moringa oleifera leaf extract.MTT assay results revealed no significant change in proliferation of Mcf-7 cells following 24 h treatment with fraction A (petroleum ether). However, significant antiproliferative effect was observed at 200 µg/mL dose of fraction B (ethyl acetate) and cell viability was reduced to 40%.In conclusion, the data suggested that all the compounds with highest negative docking score than the reference could be the potential candidates for cyclin dependent kinase-2 (CDK-2) inhibition while ellagic acid, chlorogenic acid and quercetin being the most stable and potent inhibitors to treat estrogen receptor positive breast cancer targeting CDK-2. Moreover, the data suggested that further investigation is required to determine the optimum dose for significant antiproliferative effects using in-vivo models to validate our findings of in-silico analysis.

Sanggenol B, a plant bioactive, as a safer alternative to tackle cancer by antagonising human FGFR.

Fibroblast Growth Receptor Factor (FGFR) are a family of proteins which are, in addition to their biological role, are involved in various pathological functions, such as cancer cellular proliferation, and metastasis. Deregulation of FGFRs at various points could result in malignancy. A conformational transition of the DFG (Asp-Phe-Gly) motif can switch the enzyme from a catalytically active (DFG-in) to an inactive (DFG-out) state. There are a few FDFR inhibitors which have received approval from the FDA, but these have adverse side effects. Hence, there is a demand for safer alternatives. With this aim, Ligand and Structure based virtual screening was carried to identify suitable lead molecule. In this process, Four Featured atom-based 3D Pharmacophore with quantitative structure-activity relationship analysis (3D-QSAR) was developed. The External validation of the hypothesis was carried invoking criteria such as Area under the ROC curve. Natural plant compound databases such as the Traditional Chinese medicine, NPACT and the ZINC Natural databases were chosen for pharmacophore filtering, which was followed by virtual screening against FGFR isoforms. The compound Sanggenol B was identified as the most suitable lead molecule. Structural stability of the protein-ligand complex and interactions of the ligand (Sanggenol B & the reference compound Ponatinib) with FGFR were analysed for 1000 ns (triplicate) by means of molecular simulation and the binding free energy was calculated using MMGBSA. Sanggenol B (PubChem CID: 15233694) binds effectively at the active site with favourable energies and is proposed as a safe alternative from a natural source.Communicated by Ramaswamy H. Sarma.

Terpenoid phytocompounds from mangrove plant Xylocarpus moluccensis as possible inhibitors against SARS-CoV-2: In silico strategy.

COVID-19 shook the world during the pandemic, where the climax it reached was vaccine manufacturing at an unfathomable pace. Alternative promising solutions to prevent infection from SARS-CoV-2 and its variants will remain crucial in the years to come. Due to its key role in viral replication, the major protease (Mpro) enzyme of SARS-CoV-2 can be an attractive therapeutic target. In the present work, natural terpenoids from mangrove medicinal plant Xylocarpus moluccensis (Lam.) M. Roem. were screened using computational methods for inhibition of Mpro protein. Out of sixty-seven terpenoids, Angolensic acid methyl ester, Moluccensin V, Thaixylomolin F, Godavarin J, and Xylomexicanolide A were shortlisted based on their docking scores and interaction affinities (- 13.502 to - 15.52 kcal/mol). The efficacy was validated by the 100 ns molecular dynamics study. Lead terpenoids were within the acceptable range of RMSD and RMSF with a mean value of 2.5 Å and 1.5 Å, respectively indicating that they bound tightly within Mpro and there was minimal fluctuation and stability of Mpro upon binding of these terpenoids. The utmost favorable binding strengths as calculated by MM-GBSA, were of Angolensic acid methyl ester and Moluccensin V with binding free energies (ΔGbind) of - 39.084, and - 43.160 kcal/mol, respectively. The terpenoids showed no violations in terms of Drug Likeliness and ADMET predictions. Overall, the findings indicate that Angolensic acid methyl ester and Moluccensin V are effective terpenoids having strong binding interaction with Mpro protein, which must be tested in vitro as an effective anti-SARS-CoV-2 drug.

In-silico and in-vitro assessments of some fabaceae, rhamnaceae, apocynaceae, and anacardiaceae species against Mycobacterium tuberculosis H37Rv and triple-negative breast cancer cells.

Medicinal plants play a huge role in the treatment of various diseases in the Limpopo province (South Africa). Traditionally, concoctions used for treating tuberculosis and cancer are sometimes prepared from plant parts naturally occurring in the region, these include (but not limited to) Schotia brachypetala, Rauvolfia caffra, Schinus molle, Ziziphus mucronate, and Senna petersiana. In this study, the aim was to evaluate the potential antimycobacterial activity of the five medicinal plants against Mycobacterium smegmatis mc2155, Mycobacterium aurum A + , and Mycobacterium tuberculosis H37Rv, and cytotoxic activity against MDA-MB 231 triple-negative breast cancer cells. Phytochemical constituents present in R. caffra and S. molle were tentatively identified by LC-QTOF-MS/MS as these extracts showed antimycobacterial and cytotoxic activity. A rigorous Virtual Screening Workflow (VSW) of the tentatively identified phytocompounds was then employed to identify potential inhibitor/s of M. tuberculosis pantothenate kinase (PanK). Molecular dynamics simulations and post-MM-GBSA free energy calculations were used to determine the potential mode of action and selectivity of selected phytocompounds. The results showed that plant crude extracts generally exhibited poor antimycobacterial activity, except for R. caffra and S. molle which exhibited average efficacy against M. tuberculosis H37Rv with minimum inhibitory concentrations between 0.25-0.125 mg/mL. Only one compound with a favourable ADME profile, namely, norajmaline was returned from the VSW. Norajmaline exhibited a docking score of -7.47 kcal/mol, while, pre-MM-GBSA calculation revealed binding free energy to be -37.64 kcal/mol. All plant extracts exhibited a 50% inhibitory concentration (IC50) of < 30 µg/mL against MDA-MB 231 cells. Flow cytometry analysis of treated MDA-MB 231 cells showed that the dichloromethane extracts from S. petersiana, Z. mucronate, and ethyl acetate extracts from R. caffra and S. molle induced higher levels of apoptosis than cisplatin. It was concluded that norajmaline could emerge as a potential antimycobacterial lead compound. Validation of the antimycobacterial activity of norajmaline will need to be performed in vitro and in vivo before chemical modifications to enhance potency and efficacy are done. S. petersiana, Z. mucronate, R.caffra and S. molle possess strong potential as key contributors in developing new and effective treatments for triple-negative breast cancer in light of the urgent requirement for innovative therapeutic solutions.

Antioxidant evaluation and computational prediction of prospective drug-like compounds from polyphenolic-rich extract of Hibiscus cannabinus L. seed as antidiabetic and neuroprotective targets: assessment through in vitro and in silico studies.

BACKGROUND: Reports have implicated diabetes mellitus (DM) and Alzheimer's disease (AD) as some of the global persistent health challenges with no lasting solutions, despite of significant inputs of modern-day pharmaceutical firms. This study therefore, aimed to appraise the in vitro antioxidant potential, enzymes inhibitory activities, and as well carry out in silico study on bioactive compounds from polyphenolic-rich extract of Hibiscus cannabinus seed (PEHc). METHODS: In vitro antioxidant assays were performed on PEHc using standard methods while the identification of phytoconstituents was carried out with high performance liquid chromatography (HPLC). For the in silico molecular docking using Schrodinger's Grid-based ligand docking with energetics software, seven target proteins were retrieved from the database ( https://www.rcsb.org/ ). RESULTS: HPLC technique identified twelve chemical compounds in PEHc, while antioxidant quantification revealed higher total phenolic contents (243.5 ± 0.71 mg GAE/g) than total flavonoid contents (54.06 ± 0.09 mg QE/g) with a significant (p < 0.05) inhibition of ABTS (IC50 = 218.30 ± 0.87 µg/ml) and 1, 1-diphenyl-2-picrylhydrazyl free radicals (IC50 = 227.79 ± 0.74 µg/ml). In a similar manner, the extract demonstrated a significant (p < 0.05) inhibitory activity against α-amylase (IC50 = 256.88 ± 6.15 µg/ml) and α-glucosidase (IC50 = 183.19 ± 0.23 µg/ml) as well as acetylcholinesterase (IC50 = 262.95 ± 1.47 µg/ml) and butyrylcholinesterase (IC50 = 189.97 ± 0.82 µg/ml), respectively. Furthermore, In silico study showed that hibiscetin (a lead) revealed a very strong binding affinity energies for DPP-4, (PDB ID: 1RWQ) and α-amylase (PDB ID: 1SMD), gamma-tocopherol ( for peptide-1 receptor; PDB ID: 3C59, AChE; PDB ID: 4EY7 and BChE; PDB ID: 7B04), cianidanol for α-glucosidase; PDB ID: 7KBJ and kaempferol for Poly [ADP-ribose] polymerase 1 (PARP-1); PDB ID: 6BHV, respectively. More so, ADMET scores revealed drug-like potentials of the lead compounds identified in PEHc. CONCLUSION: As a result, the findings of this study point to potential drug-able compounds in PEHc that could be useful for the management of DM and AD.

Repositioning Cannabinoids and Terpenes as Novel EGFR-TKIs Candidates for Targeted Therapy Against Cancer: A virtual screening model using CADD and biophysical simulations.

This study examines the potential of Cannabis sativa L. plants to be repurposed as therapeutic agents for cancer treatment through designing of hybrid Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). A set of 50 phytochemicals was taken from Cannabinoids and Terpenes and subjected for screening using Semi-flexible and Flexible Molecular Docking methods, MM-GBSA free binding energy computations, and pharmacokinetic/pharmacodynamic (ADME-Tox) predictions. Nine promising phytochemicals, Cannabidiolic acid (CBDA), Cannabidiol (CBD), Tetrahydrocannabivarin (THCV), Dronabinol (Δ-9-THC), Delta-8-Tetrahydrocannabinol (Δ-8-THC), Cannabicyclol (CBL), Delta9-tetrahydrocannabinolic acid (THCA), Beta-Caryophyllene (BCP), and Gamma-Elemene (γ-Ele) were identified as potential EGFR-TKIs natural product candidates for cancer therapy. To further validate these findings, a set of Molecular Dynamics simulations were conducted over a 200 ns trajectory. This hybrid early drug discovery screening strategy has the potential to yield a new generation of EGFR-TKIs based on natural cannabis products, suitable for cancer therapy. In addition, the application of this computational strategy in the virtual screening of both natural and synthetic chemical libraries could support the discovery of a wide range of lead drug agents to address numerous diseases.

(R)-(+)-Rosmarinic Acid as an Inhibitor of Herpes and Dengue Virus Replication: an In Silico Assessment.

Since ancient times, viruses such as dengue, herpes, Ebola, AIDS, influenza, chicken meat, and SARS have been roaming around causing great health burdens. Currently, the prescribed antiviral drugs have not cured the complications caused by viruses, whereas viral replication was not controlled by them. The treatments suggested are not only ineffectual, but also sometimes inefficient against viruses at all stages of the viral cycle as well. To fight against these contagious viruses, people rely heavily on medicinal plants to enhance their innate and adaptive immune systems. In this research, the preparation of ligands and proteins was performed using the Maestro V.13.2 module tool. This software, consisting of LigPrep, Grid Generation, SiteMap, and Glide XP, has each contributed significantly to the preparation of ligands and proteins. Ultimately, the research found that (R)-(+)-rosmarinic acid was found to have significant docking scores of - 10.847 for herpes virus, of - 10.033 for NS5, and - 7.259 for NS1. In addition, the Prediction of Activity Spectra for Substances (PASS) server indicates that rosmarinic acid possesses a diverse spectrum of enzymatic activities, as probability active (Pa) values start at > 0.751, whereas it has fewer adverse effects than the drugs prescribed for viruses. Accordingly, it was found the rate of acute toxicity values of (R)-(+)-rosmarinic acid at doses LD50 log10 (mmol/g) and LD50 (mg/g) in different routes of administration, such as intraperitoneal, intravenous, oral, and subcutaneous. Ultimately, the present study concluded that (R)-(+)-rosmarinic acid would expose significant antiviral effects in in vitro and in vivo experiments, and this research would be a valuable asset for the future, especially for those who wish to discover a drug molecule for a variety of viruses. Supplementary Information: The online version contains supplementary material available at 10.1007/s43450-023-00381-y.

Exploration of potent antiviral phytomedicines from Lauraceae family plants against SARS-CoV-2 RNA-dependent RNA polymerase.

RNA-dependent RNA polymerase, also known as RdRp, is a possible therapeutic target that could be used to suppress the proliferation of RNA viruses such as SARS-CoV-2. This protein has two major functional sites (a) catalytic and (b) substrate entry, which regulate the natural substrate entry and its corresponding interaction with the protein. In this study, a computational drug design pipeline was applied to investigate potential inhibitors against SARS-CoV-2 RdRp from Lauraceae plants, and five top hits were selected based on the docked score (< -7 kcal/mol). The docking study suggested that the Glochidioboside had a minimum binding score of -7.8 kcal/mol. This compound showed total five hydrogen bonds while two of them were with catalytic residues Asp618 and Asp760. However, another compound, Sitogluside showed a binding score of -7.3 kcal/mol with four hydrogen bonds targeting three functional residues (Arg555, Ser759, and Asp760). Later, 100 ns explicit solvent molecular dynamics (MD) simulation was performed to evaluate the stability of the protein-ligand docked system. These compounds translocated their positions from the catalytic site to the substrate entry site, as observed in the MD simulation trajectory. However, translocation did not affect the binding strength of these compounds, and they retained the strong binding affinity (ΔG < -11.5 kcal/mol), estimated using the MM/GBSA method. In general, the findings of this study indicated the potential therapeutic compounds that may be used targeting SARS-CoV-2 RdRp. However, these compounds still need to be validated by experimentation in order to determine their inhibitory function.Communicated by Ramaswamy H. Sarma.

Multitarget Potential of Phytochemicals from Traditional Medicinal Tree, Terminalia arjuna (Roxb. ex DC.) Wight & Arnot as Potential Medicaments for Cardiovascular Disease: An In-Silico Approach.

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. Terminalia arjuna (Roxb. ex DC.) Wight & Arnot of the Combretaceae family is one of the most frequently approved and utilized medicinal trees in the traditional medicinal system, which was used for the treatment of a variety of diseases, including cardiovascular disorders. The present study aims to identify phytochemicals from T. arjuna, that do not exhibit any toxicity and have significant cardioprotective activity using an in-silico technique. Four different cardiovascular proteins, namely human angiotensin receptor (PDB ID: 4YAY), P38 mitogen-activated protein kinase (MAPK, PDB ID: 4DLI), 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-Co A) reductase (PDB ID: 1HW9), and human C-reactive protein (PDB ID: 1B09), were used as target proteins to identify potential inhibitors using a virtual screening of the phytochemicals in T. arjuna revealed casuarinin as a potential inhibitor of all selected target proteins with strong binding energy. Furthermore, MD simulations for a 100 ns time scale also revealed that most of the key protein contacts of all target proteins were retained throughout the simulation trajectories. Binding free energy calculations using the MM-GBSA approach also support a strong inhibitory effect of casuarinin on target proteins. Casuarinin's effective binding to these proteins lays the groundwork for the development of broad-spectrum drugs as well as the understanding of the underlying mechanism against cardiovascular diseases through in vivo and clinical studies.

Phenolic compounds from Tradescantia pallida ameliorate diabetes by inhibiting enzymatic and non-enzymatic pathways.

Diabetes is a chronic metabolic disorder marked by postprandial hyperglycemia due to several etiologies including abnormal carbohydrate digestion and glycation of hemoglobin. The prolong use of synthetic drugs results in characteristic side effects which necessitates the discovery of safe and cost-effective substitutes. The aim of the current study is to isolate and evaluate the antidiabetic potential of the phenolic compounds from the leaves of Tradescantia pallida. Syringic acid, p-coumaric acid, morin and catechin (compounds 1-4) were isolated and characterized from Tradescantia pallida leaves using column chromatography and spectroscopic techniques. The in vitro antidiabetic potential of the phenolic compounds were assessed using α-amylase and non-enzymatic glycosylation of hemoglobin protein assays. A mechanistic insight of interactions between phenolic compounds and human α-amylase and hemoglobin protein were scrutinized by employing molecular docking method. Prime Molecular Mechanics/Generalized Born Surface Area (MM-GBSA) calculations were carried out to find the binding energies of the ligand-protein complexes. Morin and catechin were further analyzed to find the dynamic and thermodynamic constraints of the complexes under specific biological conditions using molecular dynamic simulation trajectories. The stability and flexibility of the complexes were justified by fluctuation of α-carbon chain, Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF) and type of interactions involved which authenticated the in vitro inhibitory potential of morin and catechin against enzymatic and non-enzymatic pathways. The current study could be fruitful in rational designing of safe antidiabetic drugs of natural origin.Communicated by Ramaswamy H. Sarma.

Glycyrrhizin as a promising kryptonite against SARS-CoV-2: Clinical, experimental, and theoretical evidences.

COVID-19 is the most devastating disease in recent times affecting most people globally. The higher rate of transmissibility and mutations of SARS-CoV-2 along with the lack of potential therapeutics has made it a global crisis. Potential molecules from natural sources could be a fruitful remedy to combat COVID-19. This systematic review highlights the detailed therapeutic implication of naturally occurring glycyrrhizin and its related derivatives against COVID-19. Glycyrrhizin has already been established for blocking different biomolecular targets related to the SARS-CoV-2 replication cycle. In this article, several experimental and theoretical evidences of glycyrrhizin and related derivatives have been discussed in detail to evaluate their potential as a promising therapeutic strategy against COVID-19. Moreover, the implication of glycyrrhizin in traditional Chinese medicines for alleviating the symptoms of COVID-19 has been reviewed. The potential role of glycyrrhizin and related compounds in affecting various stages of the SARS-CoV-2 life cycle has also been discussed in detail. Derivatization of glycyrrhizin for designing potential lead compounds along with combination therapy with other anti-SARS-CoV-2 agents followed by extensive evaluation may assist in the formulation of novel anti-coronaviral therapy for better treatment to combat COVID-19.

Exploring molecular docking with MM-GBSA and molecular dynamics simulation to predict potent inhibitors of cyclooxygenase (COX-2) enzyme from terpenoid-based active principles of Zingiber species.

Cyclooxygenase 2 (COX-2), the key enzyme involved in prostaglandin (PGs) production, is known to take part in inflammatory and immune responses. Though COX-2 inhibitors are therapeutically effective anti-inflammatory drugs, they deficit anti-thrombotic activity thus leading to increased cardiovascular diseases. Therefore, COX-2 inhibitors with improved therapeutic efficacy and tolerance are still needed. In recent years, traditional medicine systems have paid attention to the essential oil of genus Zingiber, particularly for the treatment of various inflammatory illnesses, with lesser side effects. Thus, the present study aims to explore the anti-inflammatory activity of Zingiber essential oil through computational-biology approaches. In this regard, virtual screening, molecular docking, and simulations were carried out on 53 compounds derived from the essential oil of Zingiber species in order to provide mechanistic insights into COX-2 inhibition and identify the most actively potent anti-inflammatory compounds. Among all the docked ligands, epi-cubenol, δ-cadinene, γ-eudesmol, cubenol, and α-terpineol were found to be powerful bioactive compounds with an increased binding affinity towards COX-2 along with favorable physiochemical properties. Additionally, MD simulation in DPPC lipid bilayers was studied to examine the intrinsic dynamics and adaptability of the chosen ligands and COX-2-complexes. The findings showed that the selected five components interacted steadily with the COX-2 active site residues throughout the simulation via different bondings. The integrative-computational approach showed that the identified natural compounds may be taken into further consideration for potential in vitro and in vivo evaluation as COX-2 inhibitors, which would lead to the development of more potent and efficient anti-inflammatory drugs.Communicated by Ramaswamy H. Sarma.

QSAR, Molecular Docking, MD Simulation and MMGBSA Calculations Approaches to Recognize Concealed Pharmacophoric Features Requisite for the Optimization of ALK Tyrosine Kinase Inhibitors as Anticancer Leads.

ALK tyrosine kinase ALK TK is an important target in the development of anticancer drugs. In the present work, we have performed a QSAR analysis on a dataset of 224 molecules in order to quickly predict anticancer activity on query compounds. Double cross validation assigns an upward plunge to the genetic algorithm−multi linear regression (GA-MLR) based on robust univariate and multivariate QSAR models with high statistical performance reflected in various parameters like, fitting parameters; R2 = 0.69−0.87, F = 403.46−292.11, etc., internal validation parameters; Q2LOO = 0.69−0.86, Q2LMO = 0.69−0.86, CCCcv = 0.82−0.93, etc., or external validation parameters Q2F1 = 0.64−0.82, Q2F2 = 0.63−0.82, Q2F3 = 0.65−0.81, R2ext = 0.65−0.83 including RMSEtr < RMSEcv. The present QSAR evaluation successfully identified certain distinct structural features responsible for ALK TK inhibitory potency, such as planar Nitrogen within four bonds from the Nitrogen atom, Fluorine atom within five bonds beside the non-ring Oxygen atom, lipophilic atoms within two bonds from the ring Carbon atoms. Molecular docking, MD simulation, and MMGBSA computation results are in consensus with and complementary to the QSAR evaluations. As a result, the current study assists medicinal chemists in prioritizing compounds for experimental detection of anticancer activity, as well as their optimization towards more potent ALK tyrosine kinase inhibitor.

In silico testing of flavonoids as potential inhibitors of protease and helicase domains of dengue and Zika viruses.

Background: Dengue and Zika are two major vector-borne diseases. Dengue causes up to 25,000 deaths and nearly a 100 million cases worldwide per year, while the incidence of Zika has increased in recent years. Although Zika has been associated to fetal microcephaly and Guillain-Barré syndrome both it and dengue have common clinical symptoms such as severe headache, retroocular pain, muscle and join pain, nausea, vomiting, and rash. Currently, vaccines have been designed and antivirals have been identified for these diseases but there still need for more options for treatment. Our group previously obtained some fractions from medicinal plants that blocked dengue virus (DENV) infection in vitro. In the present work, we explored the possible targets by molecular docking a group of molecules contained in the plant fractions against DENV and Zika virus (ZIKV) NS3-helicase (NS3-hel) and NS3-protease (NS3-pro) structures. Finally, the best ligands were evaluated by molecular dynamic simulations. Methods: To establish if these molecules could act as wide spectrum inhibitors, we used structures from four DENV serotypes and from ZIKV. ADFR 1.2 rc1 software was used for docking analysis; subsequently molecular dynamics analysis was carried out using AMBER20. Results: Docking suggested that 3,5-dicaffeoylquinic acid (DCA01), quercetin 3-rutinoside (QNR05) and quercetin 3,7-diglucoside (QND10) can tightly bind to both NS3-hel and NS3-pro. However, after a molecular dynamics analysis, tight binding was not maintained for NS3-hel. In contrast, NS3-pro from two dengue serotypes, DENV3 and DENV4, retained both QNR05 and QND10 which converged near the catalytic site. After the molecular dynamics analysis, both ligands presented a stable trajectory over time, in contrast to DCA01. These findings allowed us to work on the design of a molecule called MOD10, using the QND10 skeleton to improve the interaction in the active site of the NS3-pro domain, which was verified through molecular dynamics simulation, turning out to be better than QNR05 and QND10, both in interaction and in the trajectory. Discussion: Our results suggests that NS3-hel RNA empty binding site is not a good target for drug design as the binding site located through docking is too big. However, our results indicate that QNR05 and QND10 could block NS3-pro activity in DENV and ZIKV. In the interaction with these molecules, the sub-pocket-2 remained unoccupied in NS3-pro, leaving opportunity for improvement and drug design using the quercetin scaffold. The analysis of the NS3-pro in complex with MOD10 show a molecule that exerts contact with sub-pockets S1, S1', S2 and S3, increasing its affinity and apparent stability on NS3-pro.

GC-MS profiling of Bauhinia variegata major phytoconstituents with computational identification of potential lead inhibitors of SARS-CoV-2 Mpro.

Severe acute respiratory syndrome coronavirus 2 was originally identified in Wuhan city of China in December 2019 and it spread rapidly throughout the globe, causing a threat to human life. Since targeted therapies are deficient, scientists all over the world have an opportunity to develop novel drug therapies to combat COVID-19. After the declaration of a global medical emergency, it was established that the Food and Drug Administration (FDA) could permit the use of emergency testing, treatments, and vaccines to decrease suffering, and loss of life, and restore the nation's health and security. The FDA has approved the use of remdesivir and its analogs as an antiviral medication, to treat COVID-19. The primary protease of SARS-CoV-2, which has the potential to regulate coronavirus proliferation, has been a viable target for the discovery of medicines against SARS-CoV-2. The present research deals with the in silico technique to screen phytocompounds from a traditional medicinal plant, Bauhinia variegata for potential inhibitors of the SARS-CoV-2 main protease. Dried leaves of the plant B. variegata were used to prepare aqueous and methanol extract and the constituents were analyzed using the GC-MS technique. A total of 57 compounds were retrieved from the aqueous and methanol extract analysis. Among these, three lead compounds (2,5 dimethyl 1-H Pyrrole, 2,3 diphenyl cyclopropyl methyl phenyl sulphoxide, and Benzonitrile m phenethyl) were shown to have the highest binding affinity (-5.719 to -5.580 kcal/mol) towards SARS-CoV-2 Mpro. The post MD simulation results also revealed the favorable confirmation and stability of the selected lead compounds with Mpro as per trajectory analysis. The Prime MM/GBSA binding free energy supports this finding, the top lead compound 2,3 diphenyl cyclopropyl methyl phenyl sulphoxide showed high binding free energy (-64.377 ± 5.24 kcal/mol) towards Mpro which reflects the binding stability of the molecule with Mpro. The binding free energy of the complexes was strongly influenced by His, Gln, and Glu residues. All of the molecules chosen are found to have strong pharmacokinetic characteristics and show drug-likeness properties. The lead compounds present acute toxicity (LD50) values ranging from 670 mg/kg to 2500 mg/kg; with toxicity classifications of 4 and 5 classes. Thus, these compounds could behave as probable lead candidates for treatment against SARS-CoV-2. However further in vitro and in vivo studies are required for the development of medication against SARS-CoV-2.

Interaction of Pelargonium sidoides Compounds with Lactoferrin and SARS-CoV-2: Insights from Molecular Simulations.

(1) Background: Pelargonium sidoides extracts and lactoferrin are two important natural, anti-inflammatory, and antiviral agents, which can interfere with the early stages of SARS-CoV-2 infection. Molecular docking and molecular dynamics simulation approaches have been applied to check for the occurrence of interactions of the Pelargonium sidoides compounds with lactoferrin and with SARS-CoV-2 components. (2) Methods: Computational methods have been applied to confirm the hypothesis of a direct interaction between PEL compounds and the lactoferrin protein and between Pelargonium sidoides compounds and SARS-CoV-2 Spike, 3CLPro, RdRp proteins, and membrane. Selected high-score complexes were structurally investigated through classical molecular dynamics simulation, while the interaction energies were evaluated using the molecular mechanics energies combined with generalized Born and surface area continuum solvation method. (3) Results: Computational analyses suggested that Pelargonium sidoides extracts can interact with lactoferrin without altering its structural and dynamical properties. Furthermore, Pelargonium sidoides compounds should have the ability to interfere with the Spike glycoprotein, the 3CLPro, and the lipid membrane, probably affecting the functional properties of the proteins inserted in the double layer. (4) Conclusion: Our findings suggest that Pelargonium sidoides may interfere with the mechanism of infection of SARS-CoV-2, especially in the early stages.