scholarly journals Astaxanthin-Mediated Bacterial Lethality: Evidence from Oxidative Stress Contribution and Molecular Dynamics Simulation

2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Jamiu Olaseni Aribisala ◽  
Sonto Nkosi ◽  
Kehinde Idowu ◽  
Ismaila Olanrewaju Nurain ◽  
Gaositwe Melvin Makolomakwa ◽  
...  

The involvement of cellular oxidative stress in antibacterial therapy has remained a topical issue over the years. In this study, the contribution of oxidative stress to astaxanthin-mediated bacterial lethality was evaluated in silico and in vitro. For the in vitro analysis, the minimum inhibitory concentration (MIC) of astaxanthin was lower than that of novobiocin against Staphylococcus aureus but generally higher than those of the reference antibiotics against other test organisms. The level of superoxide anion of the tested organisms increased significantly following treatment with astaxanthin when compared with DMSO-treated cells. This increase compared favorably with those observed with the reference antibiotics and was consistent with a decrease in the concentration of glutathione (GSH) and corresponding significant increase in ADP/ATP ratio. These observations are suggestive of probable involvement of oxidative stress in antibacterial capability of astaxanthin and in agreement with the results of the in silico evaluations, where the free energy scores of astaxanthins’ complexes with topoisomerase IV ParC and ParE were higher than those of the reference antibiotics. These observations were consistent with the structural stability and compactness of the complexes as astaxanthin was observed to be more stable against topoisomerase IV ParC and ParE than DNA Gyrase A and B. Put together, findings from this study underscored the nature and mechanism of antibacterial action of astaxanthin that could suggest practical approaches in enhancing our current knowledge of antibacterial arsenal and aid in the novel development of alternative natural topo2A inhibitor.

Author(s):  
Sisir Nandi ◽  
Mohit Kumar ◽  
Mridula Saxena ◽  
Anil Kumar Saxena

Background: The novel coronavirus disease (COVID-19) is caused by a new strain (SARS-CoV-2) erupted in 2019. Nowadays, it is a great threat that claims uncountable lives worldwide. There is no specific chemotherapeutics developed yet to combat COVID-19. Therefore, scientists have been devoted in the quest of the medicine that can cure COVID- 19. Objective: Existing antivirals such as ASC09/ritonavir, lopinavir/ritonavir with or without umifenovir in combination with antimalarial chloroquine or hydroxychloroquine have been repurposed to fight the current coronavirus epidemic. But exact biochemical mechanisms of these drugs towards COVID-19 have not been discovered to date. Method: In-silico molecular docking can predict the mode of binding to sort out the existing chemotherapeutics having a potential affinity towards inhibition of the COVID-19 target. An attempt has been made in the present work to carry out docking analyses of 34 drugs including antivirals and antimalarials to explain explicitly the mode of interactions of these ligands towards the COVID-19protease target. Results: 13 compounds having good binding affinity have been predicted towards protease binding inhibition of COVID-19. Conclusion: Our in silico docking results have been confirmed by current reports from clinical settings through the citation of suitable experimental in vitro data available in the published literature.


Author(s):  
Kiptiyah Kiptiyah ◽  
Widodo Widodo ◽  
Gatot Ciptadi ◽  
Aulanni’am Aulanni’Am ◽  
Mohammad A. Widodo ◽  
...  

AbstractBackgroundWe investigated whether 10-gingerol is able to induce oxidative stress in cumulus cells.MethodsFor the in-vitro research, we used a cumulus cell culture in M199, containing 10-gingerol in various concentrations (0, 12, 16, and 20 µM), and detected oxidative stress through superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentrations, with incubation periods of 24, 48, 72, and 96 h. The obtained results were confirmed by in-silico studies.ResultsThe in-vitro data revealed that SOD activity and MDA concentration increased with increasing incubation periods: SOD activity at 0 µM (1.39 ± 0.24i), 12 µM (16.42 ± 0.35ab), 16 µM (17.28 ± 0.55ab), 20 µM (17.81 ± 0.12a), with a contribution of 71.1%. MDA concentration at 0 µM (17.82 ± 1.39 l), 12 µM (72.99 ± 0.31c), 16 µM (79.77 ± 4.19b), 20 µM (85.07 ± 2.57a), with a contribution of 73.1%. Based on this, the in-silico data uncovered that 10˗gingerol induces oxidative stress in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT˗1.Conclusions10-gingerol induces oxidative stress in cumulus cells through enhancing SOD activity and MDA concentration by inhibiting HTR1A functions and inactivating GSK3B and AKT˗1.


Author(s):  
Amey Sharma ◽  
Apoorva Rana ◽  
Lakshya Mangtani ◽  
Aakanksha Kalra ◽  
Ravi Ranjan Kumar Niraj

Background: Infections caused by drug resistant microorganisms have been increasing worldwide thereby being one of the major causes of morbidity in the 21st century. Klebsiella pneumoniae is one such bacteria causing lung inflammation, lung injury and death. Emergence of hyper-virulent and drug resistant species such as ESBL and CRKP has made this microbe a serious and urgent threat. The pace of emergence of these species is outgrowing the development of novel drug and vaccine candidates thereby focusing on drug repurposing approach. Objective: 1. Homology Modelling of Thymidylate Synthase. 2. Verification of Modelled Structure. 3. Molecular Docking. 4. Molecular Dynamic Simulation of Docked Complex. 5. In vitro analysis of 5-FU activity against Klebsiella pneumonia. Method: The 3-D structure of Thymidylate Synthase was predicted using Swiss-Model server and validated by in silico approaches. - Determination protein-protein interactions using STRING database. - Molecular docking. - MD simulations of 5-FU with predicted structure of thymidylate synthase. - In vitro antimicrobial drug sensitivity assay at different concentrations. Result: Hydrogen bond was observed in Molecular Docking - Protein-ligand complex remains stable during simulation. - 5-FU shows antimicrobial activity against Klebsiella pneumonia during In vitro study. Conclusion: Both In silico as well as in vitro analysis have indicated that 5-FU can potentially be developed as an antimicrobial agent towards Klebsiella pneumonia


Author(s):  
Ashis Kumar Goswami ◽  
Hemanta Kumar Sharma ◽  
Neelutpal Gogoi ◽  
Ankita Kashyap ◽  
Bhaskar Jyoti Gogoi

Background: Malaria is caused by different species of Plasmodium; among which P. falciparum is the most severe. Coptis teeta is an ethnomedicinal plant of enormous importance for tribes of north east India. Objective: In this study, the anti malarial activity of the methanol extracts of Coptis teeta was evaluated in vitro and lead identification via in silico study. Method: On the basis of the in vitro results, in silico analysis by application of different modules of Discovery Studio 2018 was performed on multiple targets of P. falciparum taking into consideration some of the compounds reported from C. teeta. Results: The IC50 of the methanol extract of Coptis teeta 0.08 µg/ml in 3D7 strain and 0.7 µg/ml in Dd2 strain of P. falciparum. From the docking study, noroxyhydrastatine was observed to have better binding affinity in comparison to chloroquine. The binding of noroxyhydrastinine with dihydroorotate dehydrogenase was further validated by molecular dynamics simulation and was observed to be significantly stable in comparison to the co-crystal inhibitor. During simulations it was observed that noroxyhydrastinine retained the interactions, giving strong indications of its effectiveness against the P. falciparum proteins and stability in the binding pocket. From the Density-functional theory analysis, the band gap energy of noroxyhydrastinine was found to be 0.186 Ha indicating a favourable interaction. Conclusion: The in silico analysis as an addition to the in vitro results provide strong evidence of noroxyhydrastinine as an anti malarial agent.


2019 ◽  
Vol 14 (11) ◽  
pp. 1900125 ◽  
Author(s):  
Ly N. Nguyen ◽  
Martina Baumann ◽  
Heena Dhiman ◽  
Nicolas Marx ◽  
Valerie Schmieder ◽  
...  

2020 ◽  
Vol 327 ◽  
pp. 127045 ◽  
Author(s):  
Ismail Yener ◽  
Safak Ozhan Kocakaya ◽  
Abdulselam Ertas ◽  
Bahadır Erhan ◽  
Erhan Kaplaner ◽  
...  

2019 ◽  
Vol 47 (5-6) ◽  
pp. 221-227
Author(s):  
Blanca Rodriguez

Safety and efficacy testing is a crucial part of the drug development process, and several different methods are used to obtain the necessary data (e.g. in vitro testing, animal trials and clinical trials). Our group has been investigating the potential of modelling and simulation as an alternative approach to some of the methods used for testing drugs for cardiac effects. To achieve our goal of developing and promoting novel approaches in drug development, we formed multidisciplinary collaborations that included clinicians, computer scientists and biologists. Our in silico models are based on human data (e.g. magnetic resonance images, electrocardiogram) and on current knowledge of human electrophysiology, thus generating predictions that are directly applicable to humans. Such models are a particularly powerful tool because they encompass different sources of population heterogeneity, which is crucial for drug testing and for assessing how interindividual variability might affect clinical endpoints. Our group has shown that computer modelling can be used to predict the effects of a test drug in a virtual population or in combination with machine learning to predict different phenotypes when a drug is given to a diseased population. Furthermore, our user-friendly drug testing software is freely available and is being adopted by industry in their drug development process. We have been engaging with industry and regulators to show that our models can contribute to the replacement of animals in drug development. Our ambition is to generate models for simulation of different diseases and therapies for investigations from subcellular to whole organ.


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