α-Glucosidase inhibitory potential of Oroxylum indicum using molecular docking, molecular dynamics, and in vitro evaluation.

Background: According to the International Diabetes Federation, there will be 578 million individuals worldwide with diabetes by 2030 and 700 million by 2045. One of the promising drug targets to fight diabetes is α-glucosidase (AG), and its inhibitors may be used to manage diabetes by reducing the breakdown of complex carbohydrates into simple sugars. The study aims to identify and validate potential AG inhibitors in natural sources to combat diabetes. Methods: Computational techniques such as structure-based virtual screening and molecular dyncamic simulation were employed to predict potential AG inhibitors from compounds of Oroxylum indicum. Finally, in silico results were validated by in vitro analysis using n-butanol fraction of crude methanol extracts. Results: The XP glide scores of top seven hits OI_13, OI_66, OI_16, OI_44, OI_43, OI_20, OI_78 and acarbose were -14.261, -13.475, -13.074, -13.045, -12.978, -12.659, -12.354 and -12.296 kcal/mol, respectively. These hits demonstrated excellent binding affinity towards AG, surpassing the known AG inhibitor acarbose. The MM-GBSA dG binding energies of OI_13, OI_66, and acarbose were -69.093, -62.950, and -53.055 kcal/mol, respectively. Most of the top hits were glycosides, indicating that active compounds lie in the n-butanol fraction of the extract. The IC50 value for AG inhibition by n-butanol fraction was 248.1 µg/ml, and for that of pure acarbose it was 89.16 µg/ml. The predicted oral absorption rate in humans for the top seven hits was low like acarbose, which favors the use of these compounds as anti-diabetes in the small intestine. Conclusion: In summary, the study provides promising insights into the use of natural compounds derived from O. indicum as potential AG inhibitors to manage diabetes. However, further research, including clinical trials and pharmacological studies, would be necessary to validate their efficacy and safety before clinical use.

Potential peptidyl arginine deiminase type 4 inhibitors from Morinda citrifolia: a structure-based drug design approach.

The World Health Organization estimates that more than 23 million individuals worldwide suffer from rheumatoid arthritis (RA), a chronic systemic autoimmune disease and experts predict that the number of RA patients may double by 2030. A substantial portion of RA patients do not respond effectively to the treatment that are already available therefore there is an urgent need of innovative new drugs. Over the past several years, Peptidyl Arginine Deiminase Type 4 (PAD4) receptors have become potential therapeutic targets for the treatment of RA. The main objective of the present study is to identify potential PAD4 inhibitors from edible fruits Morinda citrifolia. Structure based virtual screening (VS) of 60 compounds from M. citrifolia were performed to identify PAD4 inhibitors. The virtual screening of compounds resulted ten hits having XP-Glide score greater than the co-ligand (XPGS: - 8.341 kcal/mol). Three hits NF_15, NF_34, and NF_35 exhibited admirable MM-GBSA dG binding energy - 52.577, - 46.777, and - 60.711 kcal/mol, respectively. These three compounds were chosen for 100 ns molecular dynamics (MD) simulations in order to evaluate the stability and interactions. The protein-ligand complex with the highest level of stability was revealed to be NF_35. Therefore, M. citrifolia fruits may be beneficial in the treatment and prevention of rheumatoid arthritis since it contains potential hits. Supplementary Information: The online version contains supplementary material available at 10.1007/s40203-023-00147-3.

Identification of potential inhibitors of SARS-CoV-2 main protease and spike receptor from 10 important spices through structure-based virtual screening and molecular dynamic study.

The outbreak of novel coronavirus disease (COVID-19) caused by SARS-CoV-2 poses a serious threat to human health and world economic activity. There is no specific drug for the treatment of COVID-19 patients at this moment. Traditionally, people have been using spices like ginger, fenugreek and onion, etc. for the remedy of a common cold. This work identifies the potential inhibitors of the main protease (Mpro) and spike (S) receptor of SARS-CoV-2 from 10 readily available spices. These two proteins, S and Mpro, play an important role during the virus entry into the host cell, and replication and transcription processes of the virus, respectively. To identify potential molecules an in-house databank containing 1040 compounds was built-up from the selected spices. Structure-based virtual screening of this databank was performed with two important SARS-CoV-2 proteins using Glide. Top hits resulted from virtual screening (VS) were subjected to molecular docking using AutoDock 4.2 and AutoDock Vina to eliminate false positives. The top six hits against Mpro and top five hits against spike receptor subjected to 130 ns molecular dynamic simulation using GROMACS. Finally, the compound 1-, 2-, 3- and 5-Mpro complexes, and compound 17-, 18-, 19-, 20- and 21- spike receptor complexes showed stability throughout the simulation time. The ADME values also supported the drug-like nature of the selected hits. These nine compounds are available in onion, garlic, ginger, peppermint, chili and fenugreek. All the spices are edible and might be used as home remedies against COVID-19 after proper biological evaluation.

Potentiality of Moringa oleifera against SARS-CoV-2: identified by a rational computer aided drug design method.

Coronavirus disease 2019 (COVID-19) has created a global human health crisis and economic setbacks. Lack of specific therapeutics and limited treatment options against COVID-19 has become a new challenge to identify potential hits in order to develop new therapeutics. One of the crucial life cycle enzymes of SARS-CoV-2 is main protease (Mpro), which plays a major role in mediating viral replication, makes it an attractive drug target. Virtual screening and three times repeated 100 ns molecular dynamics simulation of the best hits were performed to identify potential SARS-CoV-2 Mpro inhibitors from the available compounds of an antiviral plant Moringa oleifera. Three flavonoids isorhamnetin (1), kaempferol (2) and apigenin (3) showed good binding affinity, stable protein-ligand complexes throughout the simulation time, high binding energy and similar binding poses in comparison with known SARS-CoV-2 Mpro inhibitor baicalein. Therefore, different parts of M. oleifera may be emerged as a potential preventive and therapeutic against COVID-19.

Phytochemicals of Zingiberaceae family exhibit potentiality against SARS-CoV-2 main protease identified by a rational computer-aided drug design.

Coronavirus disease 2019 (COVID-19) has created huge social, economic and human health crises globally. Discovery of specific drugs has become a new challenge to the researcher. Structure-based virtual-screening of our in-house databank containing1102 phytochemicals of Zingiberaceae family was performed with main protease(Mpro), a crucial enzyme of SARS-CoV-2. Rigorous docking and ADME study of top-scored twenty hits resulted from VS was performed. Then 100 ns molecular dynamics followed by MMPBSA binding free energy(ΔGbind) calculation of A280 and KZ133 was also performed. These two hits showed good interactions with crucial amino acid residues of Mpro HIS-41 and CYS-145, excellent ADME properties, fair ΔGbind values (> ‒188.03 kj/mol), and average protein-ligand complex RMSD < apo-protein RMSD. Therefore, the seed extracts of Alpinia blepharocalyx and rhizome extracts Kaempferia angustifolia containing A280 and KZ133, respectively, may be useful against COVID-19 after the proper biological screening. These two novel scaffolds could be exploited as potent SARS-CoV-2-Mpro inhibitors.

Identification of SARS-CoV-2 Main Protease Inhibitors Using Structure Based Virtual Screening and Molecular Dynamics Simulation of DrugBank Database.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is highly pathogenic to humans and has created an unprecedented global health care threat. Globally, intense efforts are going on to discover a vaccine or new drug molecules to control the COVID-19. However, till today, there is no effective therapeutics or treatment available for COVID-19. In this study, we aim to find out potential small molecule inhibitors for SARS-CoV-2 main protease (Mpro) from the known DrugBank database version 5.1.8. We applied structure-based virtual screening of the database containing 11875 numbers of drug candidates to identify potential hits for SARS-CoV-2 Mpro inhibitors. Seven potential inhibitors having admirable XP glide score ranging from -15.071 to -8.704 kcal/mol and good binding affinity with the active sites amino acids of Mpro were identified. The selected hits were further analyzed with 50 ns molecular dynamics (MD) simulation to examine the stability of protein-ligand complexes. The root mean square deviation and potential energy plot indicates the stability of the complexes during the 50 ns MD simulation. The MM-GBSA analysis also showed good binding energy of the selected hits (-83.2718 to -58.6618 kcal/mol). Further analysis revealed critical hydrogen bonds and hydrophobic interactions between compounds and the target protein. The compounds bind to biologically important regions of Mpro, indicating their potential to inhibit the functionality of this component.

In Silico Identification of Potential Inhibitors of ADP-Ribose Phosphatase of SARS-CoV-2 nsP3 by Combining E-Pharmacophore- and Receptor-Based Virtual Screening of Database.

The recently emerged 2019 Novel Coronavirus (SARS-CoV-2) and associated COVID-19 disease cause serious or even fatal respiratory tract infection. Observing the spread, illness and death caused by COVID-19, the World Health Organization (WHO) declared COVID-19 a pandemic. To date, there is no approved therapeutics or effective treatment available to combat the outbreak. This urgent situation is pressing the world to respond with development of novel vaccine or a small molecule therapeutics for SARS-CoV-2. In line with these efforts, the structure of several proteins of SARS-CoV-2 has been rapidly resolved and made publicly available to facilitate global efforts to develop novel drug candidates. In this paper, we aim to find out the small molecule inhibitors for ADP-ribose phosphatase of SARS-CoV-2. In order to identify potential inhibitors, we applied sequential E-pharmacophore and structure-based virtual screening (VS) of MolPort database containing 113687 number of commercially available natural compounds using Glide module. Six potential inhibitors having admirable XP glide score range from -11.009 to -14.684 kcal/mol and good binding affinity towards active sites were identified. All the molecules are commercially available for further characterization and development by scientific community. The in vitro activity of selected inhibitors can be done easily which will provide useful information for clinical treatment of novel coronavirus pneumonia.

Discovery of novel potential selective HDAC8 inhibitors by combine ligand-based, structure-based virtual screening and in-vitro biological evaluation.

Neuroblastoma is the most common extracranial solid tumor found in children and survival rate is extremely meager. HDAC8, a class I zinc-dependent enzyme, is a potential drug target for treatment of neuroblastoma and T cell lymphoma. Most of the HDAC8 inhibitors discovered till date contains a hydroxamic acid group which acts as a zinc binding group. The high binding affinity to the zinc and other ions results in adverse effects. Also, the non-selective inhibition of HDACs cause a variety of side effects. The objective of this is to identify structurally diverse, non-hydroxamate, novel, potential and selective HDAC8 inhibitors. A number of five featured pharmacophore hypotheses were generated using 32 known selective HDAC8 inhibitors. The hypotheses ADDRR.4 were selected for building 3D QSAR model. This model has an excellent correlation coefficient and good predictive ability, which was employed for virtual screening of Phase database containing 4.3 × 106 molecules. The resultant hits with fitness score >1.0 were optimized using in-silico ADMET (absorption, distribution, metabolism,  excretion, and toxicity) and XP glide docking studies. On the basis of pharmacophore matching, interacting amino acid residues, XP glide score, more affinity towards HDAC8 and less affinity towards other HDACs, and ADME results five hits- SD-01, SD-02, SD-03, SD-04 and SD-05 with new structural scaffolds,  non-hydroxamate were selected for in vitro activity study. SD-01 and SD-02 were found to be active in the nanomolar (nM) range. SD-01 had considerably good selectivity for HDAC8 over HDAC6 and SD-02 had marginal selectivity for HDAC6 over HDAC8. The compounds SD-01 and SD-02 were found to inhibit HDAC8 at concentrations (IC50) 9.0 nM and 2.7 nM, respectively.