scholarly journals In Silico and In Vitro Evaluation of the Antimicrobial Potential of Bacillus cereus Isolated from Apis dorsata Gut against Neisseria gonorrhoeae

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1401
Author(s):  
Nurdjannah Jane Niode ◽  
Aryani Adji ◽  
Jimmy Rimbing ◽  
Max Tulung ◽  
Mohammed Alorabi ◽  
...  

Antimicrobial resistance is a major public health and development concern on a global scale. The increasing resistance of the pathogenic bacteria Neisseria gonorrhoeae to antibiotics necessitates efforts to identify potential alternative antibiotics from nature, including insects, which are already recognized as a source of natural antibiotics by the scientific community. This study aimed to determine the potential of components of gut-associated bacteria isolated from Apis dorsata, an Asian giant honeybee, as an antibacterial against N. gonorrhoeae by in vitro and in silico methods as an initial process in the stage of new drug discovery. The identified gut-associated bacteria of A. dorsata included Acinetobacter indicus and Bacillus cereus with 100% identity to referenced bacteria from GenBank. Cell-free culture supernatants (CFCS) of B. cereus had a very strong antibacterial activity against N. gonorrhoeae in an in vitro antibacterial testing. Meanwhile, molecular docking revealed that antimicrobial lipopeptides from B. cereus (surfactin, fengycin, and iturin A) had a comparable value of binding-free energy (BFE) with the target protein receptor for N. gonorrhoeae, namely penicillin-binding protein (PBP) 1 and PBP2 when compared with the ceftriaxone, cefixime, and doxycycline. The molecular dynamics simulation (MDS) study revealed that the surfactin remains stable at the active site of PBP2 despite the alteration of the H-bond and hydrophobic interactions. According to this finding, surfactin has the greatest antibacterial potential against PBP2 of N. gonorrhoeae.

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Mohammad Mahfuz Ali Khan Shawan ◽  
Sajal Kumar Halder ◽  
Md. Ashraful Hasan

Abstract Background At present, the entire world is in a war against COVID-19 pandemic which has gradually led us toward a more compromised “new normal” life. SARS-CoV-2, the pathogenic microorganism liable for the recent COVID-19 outbreak, is extremely contagious in nature resulting in an unusual number of infections and death globally. The lack of clinically proven therapeutic intervention for COVID-19 has dragged the world’s healthcare system into the biggest challenge. Therefore, development of an efficient treatment scheme is now in great demand. Screening of different biologically active plant-based natural compounds could be a useful strategy for combating this pandemic. In the present research, a collection of 43 flavonoids of 7 different classes with previously recorded antiviral activity was evaluated via computational and bioinformatics tools for their impeding capacity against SARS-CoV-2. In silico drug likeness, pharmacophore and Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) profile analysis of the finest ligands were carried out using DataWarrior, DruLiTo and admetSAR programs, respectively. Molecular docking was executed by AutoDock Vina, while molecular dynamics simulation of the target protein–ligand bound complexes was done using nanoscalable molecular dynamics and visual molecular dynamics software package. Finally, the molecular target analysis of the selected ligands within Homo sapiens was conducted with SwissTargetPredcition web server. Results Out of the forty-three flavonoids, luteolin and abyssinone II were found to develop successful docked complex within the binding sites of target proteins in terms of lowest binding free energy and inhibition constant. The root mean square deviation and root mean square fluctuation values of the docked complex displayed stable interaction and efficient binding between the ligands and target proteins. Both of the flavonoids were found to be safe for human use and possessed good drug likeness properties and target accuracy. Conclusions Conclusively, the current study proposes that luteolin and abyssinone II might act as potential therapeutic candidates for SARS-CoV-2 infection. In vivo and in vitro experiments, however, should be taken under consideration to determine the efficiency and to demonstrate the mechanism of action.


Author(s):  
Yash Gupta ◽  
Dawid Maciorowski ◽  
Samantha E. Zak ◽  
Krysten A. Jones ◽  
Rahul S. Kathayat ◽  
...  

Abstract The emergence of SARS/MERS drug-resistant SARS-CoV2 comes with higher rates of transmission and mortality. Like all coronaviruses, SARS-CoV-2 is a relatively large virus consisting of several enzymes with essential functions within its proteome. Here, we focused on repurposing approved and investigational drugs by identifying potential drugs that are predicted to effectively inhibit critical enzymes. We targeted seven proteins with enzymatic activities known to be essential at different stages of the viral multiplication cycle including PLpro, 3CLpro, RdRP, Helicase, ExoN, NendoU, and 2’-O-MT. For virtual screening, the energy minimization of a crystal structure of the modeled protein was carried out using the Protein Preparation Wizard(Schrodinger LLC 2020-1). Following active site selection based on data mining and COACH predictions, we performed a high-throughput virtual screen of drugs (n=5903) that are approved by worldwide regulatory bodies. The screening was performed against viral targets using three sequential docking modes (i.e. HTVS, SP, and XP). Our in-silico virtual screening identified ~290 potential drugs based on the criteria of energy, docking parameters, ligand, and binding site strain and score. Drugs specific to each target protein were further analyzed for binding free energy perturbation by molecular mechanics (prime MM-GBSA) and pruning the hits to the top 32 candidates. The top lead from each target pool was further subjected to molecular dynamics simulation using the Desmond module. Herein we report the evaluation of in-vitro efficacy of selected hit drug molecules on SARS-CoV-2 inhibition. Among eight molecules included in our evaluation, we found inhibitor of protein kinase C isoforms, Bisindolylmaleimide IX (BIM IX), as the potent inhibitor of SARS-CoV-2 in-vitro. Further, in-silico predicted target validation through enzymatic assays confirmed 3CLpro to be the target. Therefore, our data support advancing BIM IX for clinical evaluation as a potential treatment for COVID-19. This is the first study that has showcased the possibility of using bisindolylmaleimide IX to treat COVID-19 through this pipeline.


2020 ◽  
Author(s):  
Yash Gupta ◽  
Dawid Maciorowski ◽  
Samantha E. Zak ◽  
Krysten A. Jones ◽  
Rahul S. Kathayat ◽  
...  

Abstract The emergence of SARS/MERS drug-resistant COVID-19 with high transmission and mortality has recently been declared a pandemic. Like all coronaviruses, SARS-CoV-2 is a relatively large virus consisting of several enzymes with essential functions within its proteome. Here, we focused on repurposing approved and investigational drugs by identifying potential drugs that are predicted to effectively inhibit critical enzymes. We targeted seven proteins with enzymatic activities known to be essential at different stages of the virus life cycle; PLpro, 3CLpro, RdRP, Helicase, ExoN, NendoU, and 2’-O-MT. For virtual screening, the energy minimization of a crystal structure of the modeled protein was carried out using the Protein Preparation Wizard1. Following active site selection based on data mining and COACH predictions, we performed a high-throughput virtual screen of drugs (n=5903) that are approved by worldwide regulatory bodies. The screening was performed against viral targets using three sequential docking modes (i.e. HTVS, SP, and XP). Our in-silico virtual screening identified ~290 potential drugs based on the criteria of energy, docking parameters, ligand, and binding site strain and score. Drugs specific to each target protein were further analyzed for binding free energy perturbation by molecular mechanics (prime MM-GBSA) and pruning the hits to the top 32 candidates. Top lead from each target pool was further subjected to molecular dynamics simulation using the Desmond module. Herein we report the evaluation of in-vitro efficacy of selected hit drug molecules on SARS-CoV-2 virus inhibition. Among eight molecules included in our evaluation, we found the micromolar inhibitor of protein kinase C isoforms, Bisindolylmaleimide IX (BIM IX), as the most potent inhibitor of SARS-CoV-2 in-vitro. Further, in-silico predicted target validation through enzymatic assays confirmed its interaction with 3CLpro to be the target. Therefore, our data support advancing BIM IX for clinical evaluation as a potential treatment for COVID-19. This is the first study that has showcased the possibility of using bisindolylmaleimide IX to treat COVID-19 through this pipeline.


2021 ◽  
Author(s):  
Gideon Ampoma Gyebi ◽  
Oludare Ogunyemi ◽  
Ibrahim M. Ibrahim ◽  
Olalekan B. Ogunro ◽  
Adegbenro P. Adegunloye ◽  
...  

Abstract Targeting viral cell entry proteins is an emerging therapeutic strategy for inhibiting the first stage of SARS-CoV-2 infection. In this study, 106 bioactive terpenoids from African medicinal plants were screened through molecular docking analysis against human angiotensin-converting enzyme 2 (hACE2), human transmembrane protease serine 2 (TMPRSS2) and the S proteins of SARS-CoV-2, SARS-CoV and MERS-CoV. In silico ADMET and drug-likeness prediction, molecular dynamics simulation (MDS), binding free energy calculations and clustering analysis of MDS trajectories were performed on the top docked compounds to respective targets. The results revealed eight terpenoids with high binding tendencies to the catalytic residues of different targets. Pentacyclic terpenoids: 24-methylene cycloartenol and isoiguesterin interacted with the hACE2 binding hotspots for the SARS-CoV-2 Spike protein. 11-hydroxy-2 - (3,4-dihydroxybenzoyloxy) abieta -5,7,9 (11),13-tetraene-12-one, 11-hydroxy-2 -(4-hydroxybenzoyloxy)-abieta- 5,7,9(11),13-tetraene-12-one and other abietane diterpenes interacted strongly with the S1-specificy pocket of TMPRSS2. 3-benzoylhosloppone and cucurbitacin interacted with the RBD and S2 subunit of SARS-CoV-2 spike protein respectively. The predicted druggable and ADMET favourable terpenoids formed structurally stable complexes in the simulated dynamics environment. These terpenoids provides core structure that can be exploited for further lead optimization to design drugs against SARS-CoV-2 cell mediated entry, subject to further in vitro and in vivo studies.


2021 ◽  
Author(s):  
Gideon A. Gyebi ◽  
Abdo A. Elfiky ◽  
Oludare M. Ogunyemi ◽  
Ibrahim M. Ibrahim ◽  
Adegbenro P. Adegunloye ◽  
...  

Abstract An in-house library of 173 phytocompound structures from Vernonia amygdalina and Occinum gratissimum was screened against the active region of 3-Chymotrypsin-Like Protease (3CLpro) of SARS-CoV-2 in silico. Based on docking scores and reference inhibitors, a hit- list of 21 phytocompounds, with binding energies ranging from − 7.2 to -8.0 kcal/mol, was initially generated. Further docking against the 3CLpro of related coronaviruses (SARS-CoV and MERS-CoV), docking to 5 different representative conformations generated from the cluster analysis of SARS-CoV-2 3CLpro molecular dynamics simulation (MDS) trajectories, and in silico drug-likeness analyses, revealed two drug-like terpenoid structures as promising non-covalent inhibitors of SARS-CoV-2 3CLPro viz: neoandrographolide and vernolide. These terpenoid structures are accommodated within the substrate-binding pocket, and interacted with the catalytic dyad, the oxyanion loop (residues 138–145), and the S1/S2 subsites of the enzyme active site. With the aid of an array of hydrogen bonds and hydrophobic interactions with residues 142–145, these phytocompounds may stabilize the conformation of the flexible oxyanion loop; and thereby interfere with the tetrahedral oxyanion intermediate formation during proteolytic cleavage. Molecular dynamics simulation and binding free energy calculation further revealed that the terpenoid-enzyme complexes exhibit strong interactions and structural stability, which could be adapted for experimental models.


2019 ◽  
Vol 18 (31) ◽  
pp. 2731-2740 ◽  
Author(s):  
Sandeep Tiwari ◽  
Debmalya Barh ◽  
M. Imchen ◽  
Eswar Rao ◽  
Ranjith K. Kumavath ◽  
...  

Background: Mycobacterium tuberculosis, Vibrio cholerae, and pathogenic Escherichia coli are global concerns for public health. The emergence of multi-drug resistant (MDR) strains of these pathogens is creating additional challenges in controlling infections caused by these deadly bacteria. Recently, we reported that Acetate kinase (AcK) could be a broad-spectrum novel target in several bacteria including these pathogens. Methods: Here, using in silico and in vitro approaches we show that (i) AcK is an essential protein in pathogenic bacteria; (ii) natural compounds Chlorogenic acid and Pinoresinol from Piper betel and Piperidine derivative compound 6-oxopiperidine-3-carboxylic acid inhibit the growth of pathogenic E. coli and M. tuberculosis by targeting AcK with equal or higher efficacy than the currently used antibiotics; (iii) molecular modeling and docking studies show interactions between inhibitors and AcK that correlate with the experimental results; (iv) these compounds are highly effective even on MDR strains of these pathogens; (v) further, the compounds may also target bacterial two-component system proteins that help bacteria in expressing the genes related to drug resistance and virulence; and (vi) finally, all the tested compounds are predicted to have drug-like properties. Results and Conclusion: Suggesting that, these Piper betel derived compounds may be further tested for developing a novel class of broad-spectrum drugs against various common and MDR pathogens.


2021 ◽  
Vol 14 (6) ◽  
pp. 541
Author(s):  
Hani A. Alhadrami ◽  
Ahmed M. Sayed ◽  
Heba Al-Khatabi ◽  
Nabil A. Alhakamy ◽  
Mostafa E. Rateb

The COVID-19 pandemic is still active around the globe despite the newly introduced vaccines. Hence, finding effective medications or repurposing available ones could offer great help during this serious situation. During our anti-COVID-19 investigation of microbial natural products (MNPs), we came across α-rubromycin, an antibiotic derived from Streptomyces collinus ATCC19743, which was able to suppress the catalytic activity (IC50 = 5.4 µM and Ki = 3.22 µM) of one of the viral key enzymes (i.e., MPro). However, it showed high cytotoxicity toward normal human fibroblasts (CC50 = 16.7 µM). To reduce the cytotoxicity of this microbial metabolite, we utilized a number of in silico tools (ensemble docking, molecular dynamics simulation, binding free energy calculation) to propose a novel scaffold having the main pharmacophoric features to inhibit MPro with better drug-like properties and reduced/minimal toxicity. Nevertheless, reaching this novel scaffold synthetically is a time-consuming process, particularly at this critical time. Instead, this scaffold was used as a template to explore similar molecules among the FDA-approved medications that share its main pharmacophoric features with the aid of pharmacophore-based virtual screening software. As a result, cromoglicic acid (aka cromolyn) was found to be the best hit, which, upon in vitro MPro testing, was 4.5 times more potent (IC50 = 1.1 µM and Ki = 0.68 µM) than α-rubromycin, with minimal cytotoxicity toward normal human fibroblasts (CC50 > 100 µM). This report highlights the potential of MNPs in providing unprecedented scaffolds with a wide range of therapeutic efficacy. It also revealed the importance of cheminformatics tools in speeding up the drug discovery process, which is extremely important in such a critical situation.


2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Ghazala Muteeb ◽  
Adil Alshoaibi ◽  
Mohammad Aatif ◽  
Md. Tabish Rehman ◽  
M. Zuhaib Qayyum

AbstractThe recent dissemination of SARS-CoV-2 from Wuhan city to all over the world has created a pandemic. COVID-19 has cost many human lives and created an enormous economic burden. Although many drugs/vaccines are in different stages of clinical trials, still none is clinically available. We have screened a marine seaweed database (1110 compounds) against 3CLpro of SARS-CoV-2 using computational approaches. High throughput virtual screening was performed on compounds, and 86 of them with docking score <  − 5.000 kcal mol−1 were subjected to standard-precision docking. Based on binding energies (< − 6.000 kcal mol−1), 9 compounds were further shortlisted and subjected to extra-precision docking. Free energy calculation by Prime-MM/GBSA suggested RC002, GA004, and GA006 as the most potent inhibitors of 3CLpro. An analysis of ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) properties of RC002, GA004, and GA006 indicated that only RC002 (callophysin A, from red alga Callophycus oppositifolius) passed Lipinski’s, Veber’s, PAINS and Brenk’s filters and displayed drug-like and lead-like properties. Analysis of 3CLpro-callophysin A complex revealed the involvement of salt bridge, hydrogen bonds, and hydrophobic interactions. callophysin A interacted with the catalytic residues (His41 and Cys145) of 3CLpro; hence it may act as a mechanism-based competitive inhibitor. Docking energy and docking affinity of callophysin A towards 3CLpro was − 8.776 kcal mol−1 and 2.73 × 106 M−1, respectively. Molecular dynamics simulation confirmed the stability of the 3CLpro-callophysin A complex. The findings of this study may serve as the basis for further validation by in vitro and in vivo studies.


2021 ◽  
Author(s):  
Pratap Kumar Parida ◽  
Dipak Paul ◽  
Debamitra Chakravorty

<p><a>The over expression of Tumor necrosis factor-α (TNFα) has been implicated in a variety of disease and is classified as a therapeutic target for inflammatory diseases (Crohn disease, psoriasis, psoriatic arthritis, rheumatoid arthritis).Commercially available therapeutics are biologics which are associated with several risks and limitations. Small molecule inhibitors and natural compounds (saponins) were identified by researchers as lead molecules against TNFα, however, </a>they were often associated with high IC50 values which can lead to their failure in clinical trials. This warrants research related to identification of better small molecule inhibitors by screening of large compound libraries. Recent developments have demonstrated power of natural compounds as safe therapeutics, hence, in this work, we have identified TNFα phytochemical inhibitors using high throughput <i>in silico </i>screening approaches of 6000 phytochemicals followed by 200 ns molecular dynamics simulations and relative binding free energy calculations. The work yielded potent hits that bind to TNFα at its dimer interface. The mechanism targeted was inhibition of oligomerization of TNFα upon phytochemical binding to restrict its interaction with TNF-R1 receptor. MD simulation analysis resulted in identification of two phytochemicals that showed stable protein-ligand conformations over time. The two compounds were triterpenoids: Momordicilin and Nimbolin A with relative binding energy- calculated by MM/PBSA to be -190.5 kJ/Mol and -188.03 kJ/Mol respectively. Therefore, through this work it is being suggested that these phytochemicals can be used for further <i>in vitro</i> analysis to confirm their inhibitory action against TNFα or can be used as scaffolds to arrive at better drug candidates.</p>


2021 ◽  
Vol 12 (6) ◽  
pp. 7621-7632

Diabetes Mellitus is the most prevalent metabolic disorder that is increasing at an alarming rate worldwide. The unregulated glucose level leads to various types of health disorders, and one of the major diabetic complications is delayed wound healing. Due to the more side effects of synthetic drugs, there is a need to explore plants and their phytochemicals for medicinal purposes. It was found that Quercetin, a flavonoid, increases the rate of diabetic wound healing by enhancing the expression of SIRT1. This demands more insight towards Quercetin and its similar compounds, as it is hypothesized that similar compounds may have similar biological properties. Thus similarity searching was done to identify the most similar compounds of Quercetin, and then the molecular docking of the screened compounds was performed using AutoDock Vina. The unique ligands were docked into the active site of SIRT1 protein (PDB ID: 4ZZJ). The binding free energy of the interacting ligand with the protein was estimated. Six compounds were identified which possess the maximum structural similarity with Quercetin, and upon docking, it was found that gossypetin and herbacetin have similar binding modes and binding energy as that of Quercetin (-7.5 kcal/mol). Therefore, the hypothesis has been validated by in silico analysis. Our study identified two phytochemicals, Gossypetin, and Herbacetin which can prove beneficial for improving diabetic wound healing but needs to be validated further by in vitro and in vivo studies.


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