Anti-quorum sensing potential of ketoprofen and its derivatives against Pseudomonas aeruginosa: insights to in silico and in vitro studies

Anti-virulence effects of Diclofenac sodium in combination with gentamicin on Pseudomonas aeruginosa: attenuation of quorum sensing related traits and efflux pump systems

Antibiotic resistance is a major clinical and public health problem. Non-steroidal anti-inflammatory drugs (NSAIDs) could increase the susceptibility of bacteria to antibiotics and have shown broad antimicrobial activity. In this work, the effect of Diclofenac sodium alone and in combination with Gentamicin on the expression of efflux pump genes and some virulence traits in clinical isolates of P. aeruginosa was investigated. The checkerboard titration assay was used to evaluate the synergistic effect of Diclofenac sodium and Gentamicin. The relative expression of MexAB-OprM and MexXY-OprM efflux pump genes was determined using qPCR. The impact of drugs on the activity of the efflux pump and some virulence traits, including biofilm formation, swarming, swimming and twitching, and bacterial proteolytic and hemolytic activities were assessed. The minimum inhibitory concentration (MIC) of Diclofenac sodium and Gentamicin for clinical P. aeruginosa strains was 5120 and 128 µg/mL and the drugs showed synergic antibacterial activity. Diclofenac sodium reduced the expression of the mexB, mexX, and mexY genes, and increased the expression of the mexA and oprM genes. In addition, Diclofenac sodium alone and in combination with Gentamicin inhibited the activity of the bacterial efflux pump and the simultaneous treatment of P. aeruginosa with Diclofenac sodium and Gentamicin significantly reduced biofilm formation, bacterial motility, proteolytic (40.78%) and hemolytic (85%) activities compared with untreated group. This study addresses clinically relevant questions about the efficacy and potential synergistic effects of diclofenac sodium and gentamicin in treating P. aeruginosa infections that can be applicable to clinical practice.

Niclosamide as a potential antivirulence agent disrupting quorum sensing in Pseudomonas aeruginosa: A molecular and in silico approach

Pseudomonas aeruginosa is a formidable pathogen linked to various challenging infections. Quorum sensing (QS) plays a pivotal role in regulating the virulence factors of P. aeruginosa. Targeting QS represents a promising strategy for mitigating P. aeruginosa virulence. This study explores the potential of niclosamide (NIC) as an antivirulence agent, emphasizing its effects on biofilm formation, pigment production, and its molecular interaction with the QS regulator, LasR. A comprehensive methodology was employed, encompassing in-silico, molecular, and in vitro analyses to assess the antivirulence properties of NIC. Sub-inhibitory concentrations of NIC (64 μg/ml) were evaluated for their capacity to inhibit biofilm formation and pigment production in P. aeruginosa. NIC resulted in a 45.4 % reduction in biofilm formation, a 48.8 % decrease in pyocyanin production, and a 41.3 % reduction in rhamnolipid production. Furthermore, NIC displayed a dose-dependent antagonistic effect on LasR, with an IC50 of 5.82 ± 0.17 μM, without any noted agonistic activity. Molecular modeling and molecular dynamics (MD) simulations indicated that NIC interacts with LasR, hindering its dimerization and destabilizing its structure. These findings were corroborated by sedimentation velocity experiments and thermal shift assays. NIC shows considerable promise as an antivirulence agent against P. aeruginosa by disrupting the LasR-mediated QS system. Through its interaction with LasR, NIC inhibits biofilm formation and diminishes the production of critical virulence factors, making P. aeruginosa less virulent and more vulnerable to conventional antibiotics and immune responses.

Targeted inhibition of PqsR in Pseudomonas aeruginosa PAO1 quorum-sensing network by chalcones as promising antibacterial compounds

BACKGROUND

Pseudomonas aeruginosa's inherent and adapted resistance makes this pathogen a serious problem for antimicrobial treatments. Furthermore, its biofilm formation ability is the most critical armor against antimicrobial therapy, and the virulence factors, on the other hand, contribute to fatal infection and other recalcitrant phenotypic characteristics. These capabilities are harmonized through cell-cell communication called Quorum Sensing (QS), which results in gene expression regulation via three major interconnected circuits: las, rhl, and pqs system. Pqs circuit specificity in P. aeruginosa made this system an attractive target for antipseudomonal therapy. The current study focuses on novel chalcone derivatives that attenuate P. aeruginosa's pathogenicity by inhibiting the QS system. Chalcones are included in the flavonoid class of phenolic compounds. This family forms one of the greatest groups of bioactive natural products.

METHOD

The chalcone derivatives's potential activity against the QS system was evaluated through biofilm inhibition, decreased virulence factors production, and gene expression.

RESULTS

Among all the tested compounds, 5H and NMe2 chalcone derivatives reduced biofilm formation by 60.9% and 78.9%, respectively, and virulence factors production, including pyocyanin (decreased by 5H 30.9% and NMe2 30.7%) and pyoverdine (decreased by 5H 47.1% and NMe2 56.9%) and the QS gene expression (LasR, RhlR, and PqsR) more effectively than other derivatives.

CONCLUSION

These chalcone compounds can be used as a supplement besides antimicrobial chemotherapy to attenuate pseudomonas pathogenicity.

Breaking the Phalanx: Overcoming Bacterial Drug Resistance with Quorum Sensing Inhibitors that Enhance Therapeutic Activity of Antibiotics

Antibiotic-resistant bacterial infections loom over humanity as an increasing deadly threat. There exists a dire need for new treatments, especially those that synergize with our existing arsenal of antibiotic drugs to help overcome the gap in antibiotic efficacy and attenuate the development of new antibiotic-resistance in the most dangerous pathogens. Quorum sensing systems in bacteria drive the formation of biofilms, increase surface motility, and enhance other virulence factors, making these systems attractive targets for the discovery of novel antibacterials. Quorum sensing inhibitors (QSIs) are hypothesized to synergize with existing antibiotics, making bacteria more sensitive to the effects of these drugs. In this study, we aimed to find the synergistic combinations between the QSIs and known antibiotics to combat the two deadliest hospital infections - Pseudomonas aeruginosa and Acinetobacter baumannii. We mined biochemical activity databases and literature to identify known, high efficacy QSIs against these bacteria. We used these data to develop and validate a Quantitative Structure-Activity Relationship (QSAR) model for predicting QSI activity and then employed this model to identify new potential QSIs from the Inxight database of approved and investigational drugs. We then tested binary mixtures of the identified QSIs with 11 existing antibiotics using a combinatorial matrix screening approach with ten (five of each) clinical isolates of P. aeruginosa and A. baumannii. Amongst explored drug combinations, 31 exhibited a synergistic effect, including mixtures involving naldemedine and telotristat, two drugs predicted by our model with previously undescribed QSI activity. Although no mixture inhibiting all the strains was found, piperacillin combined with curcumin, ketoprofen, indomethacin, and piroxicam demonstrated the broadest antimicrobial action. We anticipate that further preclinical investigation of these combinations of novel repurposed QSIs with a known antibiotic may lead to novel clinical candidates.

Research Progress on the Combination of Quorum-Sensing Inhibitors and Antibiotics against Bacterial Resistance

Bacterial virulence factors and biofilm development can be controlled by the quorum-sensing (QS) system, which is also intimately linked to antibiotic resistance in bacteria. In previous studies, many researchers found that quorum-sensing inhibitors (QSIs) can affect the development of bacterial biofilms and prevent the synthesis of many virulence factors. However, QSIs alone have a limited ability to suppress bacteria. Fortunately, when QSIs are combined with antibiotics, they have a better therapeutic effect, and it has even been demonstrated that the two together have a synergistic antibacterial effect, which not only ensures bactericidal efficiency but also avoids the resistance caused by excessive use of antibiotics. In addition, some progress has been made through in vivo studies on the combination of QSIs and antibiotics. This article mainly expounds on the specific effect of QSIs combined with antibiotics on bacteria and the combined antibacterial mechanism of some QSIs and antibiotics. These studies will provide new strategies and means for the clinical treatment of bacterial infections in the future.

Diclofenac-loaded PLGA nanoparticles downregulate LasI/R quorum sensing genes in pathogenic P. aeruginosa isolates

Poly(lactic-co-glycolic acid) (PLGA) is a biocompatible polymer that can gradually and consistently release drugs in a controlled manner. In this study, diclofenac sodium-loaded PLGA nanoparticles (DS-PLGA NPs) were produced by solvent evaporation technique and characterized using SEM, DLS, and zeta potential analyses. The antibacterial and antivirulence potential of DS-PLGA NPs against P. aeruginosa strains were examined using broth microdilution, crystal violet staining, hemolysis, and twitching quantification assays. Furthermore, the expression of the quorum sensing (QS) genes, lasI and lasR in P. aeruginosa strains after treatment with 1/2 MIC of DS-PLGA NPs was assessed using real-time PCR. SEM imaging of the synthesized NPs exhibited that the NPs have a spherical structure with a size range of 60-150 nm. The zeta potential of the NPs was - 15.2 mV, while the size of the particles in the aquatic environment was in a range of 111.5-153.8 nm. The MIC of prepared NPs against various strains of P. aeruginosa ranged from 4.5 to 9 mg/mL. Moreover, exposure of bacteria to sub-MIC of DS-PLGA NPs significantly down-regulated the expression of the lasI and lasR genes to 0.51- and 0.75-fold, respectively. Further, prepared NPs efficiently reduced the biofilm formation of P. aeruginosa strains by 9-27%, compared with the controls. Besides, DS-PLGA NPs showed considerable attenuation in bacterial hemolytic activity by 32-88% and twitching motility by 0-32.3%, compared with untreated cells. Overall, the present work exhibited the anti-QS activity of DS-PLGA NPs, which could be a safe and useful approach for treating P. aeruginosa infections.

Ketoprofen attenuates Las/Rhl quorum-sensing (QS) systems of Pseudomonas aeruginosa: molecular and docking studies

BACKGROUND

Quorum sensing (QS) is the leading cause of persistent infections and recalcitrance to antibiotic treatment of Pseudomonas aeruginosa. Hence, QS inhibitors are promising agents for the potential treatment of P. aeruginosa infections.

METHODS AND RESULTS

Herein, the reducing effect of ketoprofen on virulence factors production including protease, hemolysin, pyocyanin, hydrogen cyanide, biofilm, and motility of P. aeruginosa strains was investigated. Furthermore, the quorum quenching activity of ketoprofen at the molecular level was examined by real-time PCR assessment. Our results showed that ketoprofen significantly attenuates virulence factors and biofilm formation in P. aeruginosa strains. Moreover, ketoprofen down-regulated the expression of lasI, lasR, rhlI, and rhlR genes, by 35-47, 22-48, 34-67, and 43-56%, respectively. As well, molecular docking simulation showed a high binding affinity of ketoprofen with QS regulatory proteins.

CONCLUSIONS

Consequently, this study confirmed the quorum quenching activity of ketoprofen, which could be employed as a useful agent for the treatment of P. aeruginosa infections.

Computer-aided analysis for identification of novel analogues of ketoprofen based on molecular docking, ADMET, drug-likeness and DFT studies for the treatment of inflammation

Computer-based drug design is increasingly used in strategies for discovering new molecules for therapeutic purposes. The targeted drug is ketoprofen (KTP), which belongs to the family of non-steroidal anti-inflammatory drugs, which are widely used for the treatment of pain, fever, inflammation and certain types of cancers. In an attempt to rationalize the search for 72 new potential anti-inflammatory compounds on the COX-2 enzyme, we carried out an in silico protocol that successfully combines molecular docking towards COX-2 receptor (5F1A), ADMET pharmacokinetic parameters, drug-likeness rules and molecular electrostatic potential (MEP). It was found that six of the compounds analyzed satisfy with the associated values to physico-chemical properties as key evaluation parameters for the drug-likeness and demonstrate a hydrophobic character which makes their solubility in aqueous media difficult and easy in lipids. All the compounds presented good ADMET profile and they showed an interaction with the amino acids responsible for anti-inflammatory activity of the COX-2 isoenzyme. The calculation of the MEP of the six analogues reveals new preferential sites involving the formation of new bonds. Consequently, this result allowed us to understand the origin of the potential increase in the anti-inflammatory activity of the candidates. Finally, it was obtained that six compounds have a binding mode, binding energy, and stability in the active site of COX-2 like the reference drug ketoprofen, suggesting that these compounds could become a powerful candidate in the inhibition of the COX-2 enzyme.Communicated by Ramaswamy H. Sarma.

Ketoprofen as an emerging contaminant: occurrence, ecotoxicity and (bio)removal

Ketoprofen, a bicyclic non-steroidal anti-inflammatory drug commonly used in human and veterinary medicine, has recently been cited as an environmental contaminant that raises concerns for ecological well-being. It poses a growing threat due to its racemic mixture, enantiomers, and transformation products, which have ecotoxicological effects on various organisms, including invertebrates, vertebrates, plants, and microorganisms. Furthermore, ketoprofen is bioaccumulated and biomagnified throughout the food chain, threatening the ecosystem function. Surprisingly, despite these concerns, ketoprofen is not currently considered a priority substance. While targeted eco-pharmacovigilance for ketoprofen has been proposed, data on ketoprofen as a pharmaceutical contaminant are limited and incomplete. This review aims to provide a comprehensive summary of the most recent findings (from 2017 to March 2023) regarding the global distribution of ketoprofen in the environment, its ecotoxicity towards aquatic animals and plants, and available removal methods. Special emphasis is placed on understanding how ketoprofen affects microorganisms that play a pivotal role in Earth's ecosystems. The review broadly covers various approaches to ketoprofen biodegradation, including whole-cell fungal and bacterial systems as well as enzyme biocatalysts. Additionally, it explores the potential of adsorption by algae and phytoremediation for removing ketoprofen. This review will be of interest to a wide range of readers, including ecologists, microbiologists, policymakers, and those concerned about pharmaceutical pollution.

Ketoprofen, Piroxicam and Indomethacin Suppressed Quorum Sensing and Virulence Factors in Acinetobacter baumannii

AIM

Quorum sensing (QS) inhibition is a promising strategy to suppress bacterial virulence, and control infection caused by Gram-negative and Gram-positive bacteria. This study explores the quorum sensing inhibiting activity of the non-steroidal anti-inflammatory drugs (NSAIDs) in Acinetobacter baumannii.

METHODS AND RESULTS

Ketoprofen, piroxicam, and indomethacin revealed QS inhibition via elimination of violacein production of the reporter strain Chromobacterium violaceum ATCC 12472 without affecting bacterial growth. The minimal inhibitory concentration (MIC) of ketoprofen, piroxicam, and indomethacin was determined against A. baumannii strains ATCC 17978, ATCC 19606, A1, A11, and A27 by the microbroth dilution method. The MICs of ketoprofen against tested isolates were 3.12-6.25 mg mL^-1 , piroxicam MICs were 1.25-2.5 mg mL^-1 , and indomethacin MICs were 3.12-12.5 mg mL^-1 . Those compounds significantly inhibited QS-associated virulence factors such as biofilm formation, and surface motility, as well as, significantly increased bacterial tolerance to oxidative stress without affecting bacterial growth. On the molecular level, the three compounds significantly inhibited the transcription of QS regulatory genes abaI/abaR, and biofilm regulated genes cusD, and pgaB. Molecular docking analysis revealed potent binding affinity of the three compounds with AbaI via hydrogen and/or hydrophobic bonds.

CONCLUSION

These results indicate that NSAIDs, ketoprofen, piroxicam, and indomethacin, could be potential inhibitors of the QS and could suppress the QS-related virulence factors of A. baumannii.

SIGNIFICANCE AND IMPACT

Ketoprofen, piroxicam, and indomethacin could provide promising implications and strategies for combating the virulence, and pathogenesis of A. baumannii.