scholarly journals Bio-Mechanism of Catechin as Pheromone Signal Inhibitor: Prediction of Antibacterial Agent Action Mode by In Vitro and In Silico Study

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6381
Author(s):  
Dikdik Kurnia ◽  
Zenika Febian Ramadhanty ◽  
Aprilina Mora Ardani ◽  
Achmad Zainuddin ◽  
Hendra Dian Adhita Dharsono ◽  
...  

The utilization of medicinal plants has long been explored for the discovery of antibacterial agents and the most effective mechanisms or new targets that can prevent and control the spread of antibiotic resistance. One kind of bacterial cell wall inhibition is the inactivation of the MurA enzyme that contributes to the formation of peptidoglycan. Another approach is to interfere with the cell–cell communication of bacteria called the Quorum sensing (QS) system. The blocking of auto-inducer such as gelatinase biosynthesis-activating pheromone (GBAP) can also suppress the virulence factors of gelatinase and serine protease. This research, in particular, aims to analyze lead compounds as antibacterial and anti-QS agents from Gambir (Uncaria gambir Roxburgh) through protein inhibition by in silico study. Antibacterial agents were isolated by bioactivity-guided isolation using a combination of chromatographic methods, and their chemical structures were determined by spectroscopic analysis methods. The in vitro antibacterial activity was evaluated by disc diffusion methods to determine inhibitory values. Meanwhile, in the in silico analysis, the compound of Uncaria gambir was used as ligand and compared with fosfomycin, ambuic acid, quercetin, and taxifolin as the standard ligand. These ligands were attached to MurA, GBAP, gelatinase, and serine proteases using Autodock Vina in PyRx 0.8 followed by PYMOL for combining the ligand conformation and proteins. plus programs to explore the complex, and visualized by Discovery Studio 2020 Client program. The antibacterial agent was identified as catechin that showed inhibitory activity against Enterococcus faecalis ATCC 29212 with inhibition zones of 11.70 mm at 10%, together with MIC and MBC values of 0.63 and 1.25 μg/mL, respectively. In the in silico study, the molecular interaction of catechin with MurA, GBAP, and gelatinase proteins showed good binding energy compared with two positive controls, namely fosfomycin and ambuic acid. It is better to use catechin–MurA (−8.5 Kcal/mol) and catechin–gelatinase (−7.8 Kcal/mol), as they have binding energies which are not marginally different from quercetin and taxifolin. On the other hand, the binding energy of serine protease is lower than quercetin, taxifolin, and ambuic acid. Based on the data, catechin has potency as an antibacterial through the inhibition of GBAP proteins, gelatinase, and serine protease that play a role in the QS system. This is the first discovery of the potential of catechin as an alternative antibacterial agent with an effective mechanism to prevent and control oral disease affected by antibiotic resistance.

Author(s):  
Eti Apriyanti ◽  
Mieke H. Satari ◽  
Dikdik Kurnia

Background: Increasing the resistance issue has become the reason for the development of new antibacterial in crucial condition. Many ways are tracked to determine the most effective antibacterial agent. Some proteins that are a key role in bacteria metabolism are targeted including MurA in cell wall biosynthesis and gelatinase biosynthesis-activating pheromone (GBAP) in Fsr Quorum Sensing (QS) system. Objective: The objective of this research is the analysis of compounds 1-4 from M. pendans as antibacterial and anti-QS activity trough protein inhibition by in silico study; focus on the structure-activity relationships, to appraise their role as an antibacterial and anti-QS agent in the molecular level. Method: Both activities of M. pendans compounds (1-4) were analyzed by in silico, comparing to Fosfomycin, Ambuic acid, Quercetin, and Taxifolin as a standard. Chemical structures of M. pendans compounds were converted using an online program molview. The compounds were docked to MurA, GBAP, gelatinase and serine protease using Autodock Vina in Pyrx 0.8 followed PYMOL to visualization and proteis.plus program to analyze of the complex. Results: All compounds from M. pendans bound on MurA, GBAP, gelatinase and serine protease except compound 2. This biflavonoid did not attach to MurA and serine protease yet is the favorable ligand for GBAP and gelatinase with the binding affinity of -6.9 and -9.4 Kcal/mol respectively. Meanwhile, for MurA and serine protease, compound 4 is the highest of bonding energy with values of -8.7 and -6.4 Kcal/mol before quercetin (MurA, -8.9 Kcal/mol) and taxifolin (serine protease, -6.6 Kcal/mol). Conclusion: Based on the data, biflavonoid acts better as anti-QS than an inhibitor of MurA enzyme while the others can be acted into both of them either therapeutic agent of anti-QS or antibacterial agent of MurA inhibitor.


2020 ◽  
Vol 353 (4) ◽  
pp. 1900309 ◽  
Author(s):  
Sherif M. H. Sanad ◽  
Ahmed A. M. Ahmed ◽  
Ahmed E. M. Mekky

2020 ◽  
Vol Volume 14 ◽  
pp. 2977-2985
Author(s):  
Dikdik Kurnia ◽  
Geofanny Sarah Hutabarat ◽  
Devi Windaryanti ◽  
Tati Herlina ◽  
Yetty Herdiyati ◽  
...  

2020 ◽  
Vol 66 (5) ◽  
pp. 378-385
Author(s):  
Y.V. Faletrov ◽  
K.A. Gilep ◽  
A.S. Falchevskaya ◽  
M.S. Horetski ◽  
J.V. Panada ◽  
...  

Molecular docking of four hydrazones of isoniazid with steroids (dehydroepiandrosterone, pregnenolone, 16α,17α-epoxypregnenolone, cholestenone) — IDHEA, IPRE, IEP5, ICHN, to mycobacterial cytochromes P450 was performed. The in silico study has shown than these hydrazones can be effectively bound to CYP121, CYP124, CYP125, CYP126A1, CYP130, and CYP51 with binding energy ranged from -9 kcal/mol to -12 kcal/mol. Calculations also demonstrated enhancement of passive lipid bilayer permeability with respect to isoniazid. In vitro IDHEA, IPRE, IEPR were found to undergo bioconversion into their 3-keto-4-en derivatives. This suggests their ability to penetrate into M. tuberculosis H37Rv cells. The results of this study are important in the context of understanding of specificity of binding of synthetic steroid derivatives to mycobacterial CYPs and indicate the possibility of using the steroid compounds studied by us as new ligands for these enzymes.


Author(s):  
Nidhi Sharma ◽  
Arti Singh ◽  
Ruchika Sharma ◽  
Anoop Kumar

Aim: The aim of the study was to find out the role of auranofin as a promising broad spectrum antibacterial agent. Methods: In-vitro assays (Percentage growth retardation, Bacterial growth kinetics, Biofilm formation assay) and In-silico study (Molegro virtual docker (MVD) version 6.0 and Molecular operating environment (MOE) version 2008.10 software). Results: The in vitro assays have shown that auranofin has good antibacterial activity against Gram positive and Gram negative bacterial strains. Further, auranofin has shown synergistic activity in combination with ampicillin against S. aureus and B. subtilis whereas in combination with neomycin has just shown additive effect against E. coli, P. aeruginosa and B. pumilus. In vivo results have revealed that auranofin alone and in combination with standard drugs significantly decreased the bioburden in zebrafish infection model as compared to control. The molecular docking study have shown good interaction of auranofin with penicillin binding protein (2Y2M), topoisomerase (3TTZ), UDP-3-O-[3- hydroxymyristoyl] N-acetylglucosaminedeacetylase (3UHM), cell adhesion protein (4QRK), β-lactamase (5CTN) and arylsulphatase (1HDH) enzyme as that of reference ligand which indicate multimodal mechanism of action of auranofin. Finally, MTT assay has shown non-cytotoxic effect of auranofin. Conclusion: In conclusion, auranofin in combination with existing antibiotics could be developed as a broad spectrum antibacterial agent; however, further studies are required to confirm its safety and efficacy. This study provides possibility of use of auranofin apart from its established therapeutic indication in combination with existing antibiotics to tackle the problem of resistance.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 733
Author(s):  
Jessica L. Spears ◽  
Richard Kramer ◽  
Andrey I. Nikiforov ◽  
Marisa O. Rihner ◽  
Elizabeth A. Lambert

With the growing popularity of probiotics in dietary supplements, foods, and beverages, it is important to substantiate not only the health benefits and efficacy of unique strains but also safety. In the interest of consumer safety and product transparency, strain identification should include whole-genome sequencing and safety assessment should include genotypic and phenotypic studies. Bacillus subtilis MB40, a unique strain marketed for use in dietary supplements, and food and beverage, was assessed for safety and tolerability across in silico, in vitro, and in vivo studies. MB40 was assessed for the absence of undesirable genetic elements encoding toxins and mobile antibiotic resistance. Tolerability was assessed in both rats and healthy human volunteers. In silico and in vitro testing confirmed the absence of enterotoxin and mobile antibiotic resistance genes of safety concern to humans. In rats, the no-observed-adverse-effect level (NOAEL) for MB40 after repeated oral administration for 14 days was determined to be 2000 mg/kg bw/day (equivalent to 3.7 × 1011 CFU/kg bw/day). In a 28 day human tolerability trial, 10 × 109 CFU/day of MB40 was well tolerated. Based on genome sequencing, strain characterization, screening for undesirable attributes and evidence of safety by appropriately designed safety evaluation studies in rats and humans, Bacillus subtilis MB40 does not pose any human health concerns under the conditions tested.


2012 ◽  
Vol 130 ◽  
pp. S167
Author(s):  
Maria Ditsa ◽  
George Geromihalos ◽  
Eleftheria Tragoulia ◽  
Dimitra Markala ◽  
Chrisa Meleti ◽  
...  

2014 ◽  
Vol 23 (6) ◽  
pp. 3220-3226 ◽  
Author(s):  
Moacyr Jesus Barreto de Melo Rêgo ◽  
Marina Rocha Galdino-Pitta ◽  
Daniel Tarciso Martins Pereira ◽  
Juliana Cruz da Silva ◽  
Marcelo Montenegro Rabello ◽  
...  

2019 ◽  
Vol 16 (32) ◽  
pp. 894-898
Author(s):  
D. F. SILVA ◽  
H. D. NETO ◽  
M. D. L. FERREIRA ◽  
A. A. O. FILHO ◽  
E. O. LIMA

β-citronellol (3,7-dimethyl-6-octen-1-ol) has been exhibiting a number of pharmacological effects that creates interest about its antimicrobial potential, since several substances of the monoterpene class have already demonstrated to possess activity in this profile. In addition, the emergence of fungal species resistant to current pharmacotherapy poses a serious challenge to health systems, making it necessary to search for new effective therapeutic alternatives to deal with this problem. In this study, the antimicrobial profile of β-citronellol was analyzed. The Prediction of Activity Spectra for Substances (PASS) online software was used to study the antimicrobial activity of the β-citronellol molecule by the use of in silico analysis. In contrast, an in vitro antifungal study of this monoterpene was carried out. For this purpose, the Minimum Inhibitory Concentration (MIC) was determined by the microdilution technique in 96-well plates in Saboraud Dextrose Broth/RPMI against sensitive strains of Candida albicans, and this assay was performed in duplicate. In the in silico analysis of the antimicrobial profile, it was revealed that the monoterpene β-citronellol had a diverse antimicrobial bioactivity profile. For the antifungal activity, it presented a percentage value with Pa: 58.4% (predominant) and its MIC of 128 μg/mL, which was equivalent for all strains tested. The in silico study of the β-citronellol molecule allowed us to consider that the monoterpenoid is very likely to be bioactive against agents that cause fungal infections.


2020 ◽  
Vol 11 (1) ◽  
pp. 20190126 ◽  
Author(s):  
B. J. M. van Rooij ◽  
G. Závodszky ◽  
A. G. Hoekstra ◽  
D. N. Ku

The influence of the flow environment on platelet aggregation is not fully understood in high-shear thrombosis. The objective of this study is to investigate the role of a high shear rate in initial platelet aggregation. The haemodynamic conditions in a microfluidic device are studied using cell-based blood flow simulations. The results are compared with in vitro platelet aggregation experiments performed with porcine whole blood (WB) and platelet-rich-plasma (PRP). We studied whether the cell-depleted layer in combination with high shear and high platelet flux can account for the distribution of platelet aggregates. High platelet fluxes at the wall were found in silico . In WB, the platelet flux was about twice as high as in PRP. Additionally, initial platelet aggregation and occlusion were observed in vitro in the stenotic region. In PRP, the position of the occlusive thrombus was located more downstream than in WB. Furthermore, the shear rates and stresses in cell-based and continuum simulations were studied. We found that a continuum simulation is a good approximation for PRP. For WB, it cannot predict the correct values near the wall.


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