Unveiling the hidden language of bacteria: anti-quorum sensing strategies for gram-negative bacteria infection control.

Quorum sensing (QS) is a communication mechanism employed by many bacteria to regulate gene expression in a population density-dependent manner. It plays a crucial role in coordinating various bacterial behaviors, including biofilm formation, virulence factor production, and antibiotic resistance. However, the dysregulation of QS can lead to detrimental effects, making it an attractive target for developing novel therapeutic strategies. Anti-QS approaches aim to interfere with QS signaling pathways, inhibiting the communication between bacteria, and disrupting their coordinated activities. Various strategies have been explored to achieve this goal. Advances in understanding QS mechanisms and the discovery of new targets have paved the way for the development of innovative anti-QS approaches. Combining multiple anti-QS strategies or utilizing them in combination with traditional antibiotics holds great promise for combating bacterial infections and addressing the challenges posed by antibiotic resistance. Anti-QS approaches offer a diverse range of strategies including natural compounds, antibody-mediated quorum quenching (QQ), computer-aided drug design for QQ, repurposing of Drugs approved by FDA as anti-QS agents and modulating quorum-sensing molecules which were discussed in detail in this review. This review, comprehensively and for the first time, sheds light on the significance of diverse anti-QS strategies in solving antimicrobial resistance problem in Gram-negative microbial infection.

Biofilm-mediated infections by multidrug-resistant microbes: a comprehensive exploration and forward perspectives.

A biofilm is a collection of microorganisms organized in a matrix of extracellular polymeric material. Biofilms consist of microbial cells that attach to both surfaces and each other, whether they are living or non-living. These microbial biofilms can lead to hospital-acquired infections and are generally detrimental. They possess the ability to resist the human immune system and antibiotics. The National Institute of Health (NIH) states that biofilm formation is associated with 65% of all microbial illnesses and 80% of chronic illnesses. Additionally, non-device-related microbial biofilm infections include conditions like cystic fibrosis, otitis media, infective endocarditis, and chronic inflammatory disorders. This review aims to provide an overview of research on chronic infections caused by microbial biofilms, methods used for biofilm detection, recent approaches to combat biofilms, and future perspectives, including the development of innovative antimicrobial strategies such as antimicrobial peptides, bacteriophages, and agents that disrupt biofilms.

Piceatannol: a renaissance in antibacterial innovation unveiling synergistic potency and virulence disruption against serious pathogens.

In the relentless battle against multi-drug resistant Gram-negative bacteria, piceatannol emerges as a beacon of hope, showcasing unparalleled antibacterial efficacy and a unique ability to disrupt virulence factors. Our study illuminates the multifaceted prowess of piceatannol against prominent pathogens-Proteus mirabilis, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae. Notably, piceatannol demonstrated a remarkable ability to inhibit biofilm formation, reduce bacterial mobility, and diminish extracellular enzyme synthesis.Mechanistic insights into piceatannol's activity unraveled its impact on membrane potential, proton motive force, and ATP production. Furthermore, our study delved into piceatannol's anti-quorum sensing (QS) activity, showcasing its potential to downregulate QS-encoding genes and affirming its affinity to critical QS receptors through molecular docking. Crucially, piceatannol exhibited a low propensity for resistance development, positioning it as a promising candidate for combating antibiotic-resistant strains. Its mild effect on red blood cells (RBCs) suggests safety even at higher concentrations, reinforcing its potential translational value. In an in vivo setting, piceatannol demonstrated protective capabilities, significantly reducing pathogenesis in mice infected with P. aeruginosa and P. mirabilis. This comprehensive analysis positions piceatannol as a renaissance in antibacterial innovation, offering a versatile and effective strategy to confront the evolving challenges posed by resilient Gram-negative pathogens.

Assessing the antibacterial potential of 6-gingerol: Combined experimental and computational approaches.

The rise of antibiotic resistance in bacteria is becoming a global concern, particularly due to the dwindling supply of new antibiotics. This situation mandates the discovery of new antimicrobial candidates. Plant-derived natural compounds have historically played a crucial role in the development of antibiotics, serving as a rich source of substances possessing antimicrobial properties. Numerous studies have supported the reputation of 6-gingerol, a prominent compound found in the ginger family, for its antibacterial properties. In this study, the antibacterial activities of 6-gingerol were evaluated against Gram-negative bacteria, Acinetobacter baumannii and Klebsiella pneumoniae, with a particular focus on the clinically significant Gram-negative Pseudomonas aeruginosa and Gram-positive bacteria Staphylococcus aureus. Furthermore, the anti-virulence activities were assessed in vitro, in vivo, and in silico. The current findings showed that 6-gingerol's antibacterial activity is due to its significant effect on the disruption of the bacterial cell membrane and efflux pumps, as it significantly decreased the efflux and disrupted the cell membrane of S. aureus and P. aeruginosa. Furthermore, 6-gingerol significantly decreased the biofilm formation and production of virulence factors in S. aureus and P. aeruginosa in concentrations below MICs. The anti-virulence properties of 6-gingerol could be attributed to its capacity to disrupt bacterial virulence-regulating systems; quorum sensing (QS). 6-Gingerol was found to interact with QS receptors and downregulate the genes responsible for QS. In addition, molecular docking, and molecular dynamics (MD) simulation results indicated that 6-gingerol showed a comparable binding affinity to the co-crystalized ligands of different P. aeruginosa QS targets as well as stable interactions during 100 ns MD simulations. These findings suggest that 6-gingerol holds promise as an anti-virulence agent that can be combined with antibiotics for the treatment of severe infections.

Drug repositioning: doxazosin attenuates the virulence factors and biofilm formation in Gram-negative bacteria.

The resistance development is an increasing global health risk that needs innovative solutions. Repurposing drugs to serve as anti-virulence agents is suggested as an advantageous strategy to diminish bacterial resistance development. Bacterial virulence is controlled by quorum sensing (QS) system that orchestrates the expression of biofilm formation, motility, and virulence factors production as enzymes and virulent pigments. Interfering with QS could lead to bacterial virulence mitigation without affecting bacterial growth that does not result in bacterial resistance development. This study investigated the probable anti-virulence and anti-QS activities of α-adrenoreceptor blocker doxazosin against Proteus mirabilis and Pseudomonas aeruginosa. Besides in silico study, in vitro and in vivo investigations were conducted to assess the doxazosin anti-virulence actions. Doxazosin significantly diminished the biofilm formation and release of QS-controlled Chromobacterium violaceum pigment and virulence factors in P. aeruginosa and P. mirabilis, and downregulated the QS encoding genes in P. aeruginosa. Virtually, doxazosin interfered with QS proteins, and in vivo protected mice against P. mirabilis and P. aeruginosa. The role of the membranal sensors as QseC and PmrA was recognized in enhancing the Gram-negative virulence. Doxazosin downregulated the membranal sensors PmR and QseC encoding genes and could in silico interfere with them. In conclusion, this study preliminary documents the probable anti-QS and anti-virulence activities of doxazosin, which indicate its possible application as an alternative or in addition to antibiotics. However, extended toxicological and pharmacological investigations are essential to approve the feasible clinical application of doxazosin as novel efficient anti-virulence agent. KEY POINTS: • Anti-hypertensive doxazosin acquires anti-quorum sensing activities • Doxazosin diminishes the virulence of Proteus mirabilis and Pseudomonas aeruginosa • Doxazosin could dimmish the bacterial espionage.

Hepatoprotective Effect of Silver Nanoparticles at Two Different Particle Sizes: Comparative Study with and without Silymarin.

Silver nanoparticles have been used for numerous therapeutic purposes because of their increased biodegradability and bioavailability, yet their toxicity remains questionable as they are known to interact easily with biological systems because of their small size. This study aimed to investigate and compare the effect of silver nanoparticles' particle size in terms of their potential hazard, as well as their potential protective effect in an LPS-induced hepatotoxicity model. Liver slices were obtained from Sprague Dawley adult male rats, and the thickness of the slices was optimized to 150 µm. Under regulated physiological circumstances, freshly cut liver slices were divided into six different groups; GP1: normal, GP2: LPS (control), GP3: LPS + AgNpL (positive control), GP4: LPS + silymarin (standard treatment), GP5: LPS + AgNpS + silymarin (treatment I), GP6: LPS + AgNpL + silymarin (treatment II). After 24 h of incubation, the plates were gently removed, and the supernatant and tissue homogenate were all collected and then subjected to the following biochemical parameters: Cox2, NO, IL-6, and TNF-α. The LPS elicited marked hepatic tissue injury manifested by elevated cytokines and proinflammatory markers. Both small silver nanoparticles and large silver nanoparticles efficiently attenuated LPS hepatotoxicity, mainly via preserving the cytokines' level and diminishing the inflammatory pathways. In conclusion, large silver nanoparticles exhibited effective hepatoprotective capabilities over small silver nanoparticles.

Biodiversity of N-acyl homoserine lactonase (aiiA) gene from Bacillus subtilis.

Microorganisms rely on the benefit of using chemical signals called autoinducers (AIs) as a connection matter in term of population, this mechanism is known as quorum sensing (QS). Quorum sensing is responsible for formation of biofilm together with virulence in bacteria. The most known QS molecule is N-acyl homoserine lactones (AHLs). A lot of degrading enzymes including lactonases that open the AHL ring and acylases that breakdown its acyl side chain can degrade or inactivate AHL. Due to similarity in lactone ring structure among AHLs it is susceptible to most of lactonases. Bacillus species are among the most promising bacteria producing AHL-lactonase. The aim of the work is to identify and study the diversity of the AHL-Lactonase gene among different Bacillus subtilis as a promising Quorum Quenching (QQ) strategy to prevent bacterial infections and biofilm formation. The AHL-lactonase (aiiA) gene of 64 B. subtilis isolates was amplified and sequenced followed by multiple sequence alignment of the translated amino acid sequences, homology modeling and docking study. An expected PCR product of about 750 base pair was detected in 22 B. subtilis isolates, and the results revealed that the isolates' sequences showed identity ranged between 97.61% and 99.47% with those in the NCBI GenBank database with 100% query coverage and 0.0 E-value. In addition, the results revealed high level of identity between many aiiA gene sequences of our isolates as they were closely related to the same sequences to many sequences of the NCBI GenBank database. The alignment of the amino acid sequences from the 22 B. subtilis isolates indicated that 84.4% of the amino acid residues were conserved between the aligned sequences. Docking of the co-crystalized ligand to wildtype and H109Y mutated protein showed a significant reduction of docking score for the mutated protein. This result indicate that this mutation might affect recognition or at least kinetics of these enzymes and hence their roles in quorum-quenching.

Innovative next-generation therapies in combating multi-drug-resistant and multi-virulent Escherichia coli isolates: insights from in vitro, in vivo, and molecular docking studies.

Despite notable advances in vaccine and antimicrobial therapies, treatment failure has been increasingly reported worldwide. Of note, multi-drug-resistant (MDR) Escherichia coli (E. coli) strains have a considerable share in the evolution of this crisis. So, current practice guidelines are directed towards complementary and alternative therapies. Therefore, we evaluated the antibacterial and antivirulence activities of curcumin, thymol, and eugenol essential oils (EOs) as well as EOs-EOs and EOs-antibiotics interactions on MDR and multi-virulent E. coli isolates. Unfortunately, MDR E. coli could be isolated with a prevalence rate of 95.6% (86/90). Additionally, the majority of our isolates harbored both fimH (95.6%) and ompA (91.1%) genes, and half of them (45/90) were multi-virulent. Interestingly, all the tested EOs, especially curcumin, exhibited inhibitory activities against all MDR and multi-virulent E. coli isolates. The addition of thymol enhanced the antibacterial activities of curcumin and eugenol. Moreover, the activities of piperacillin/tazobactam and imipenem were increased by adding any one of the tested EOs. Regarding the antivirulence activities of the tested EOs, the cell surfaces of treated E. coli isolates under transmission electron microscope (TEM) were uneven. The cells appeared damaged and lost their appendages. Furthermore, EOs strongly reduced the transcription of ompA and fimH genes. The antibacterial and antivirulence activities of the used EOs were confirmed by in silico and mice protection assays. Hereby, we introduced the promising uses of curcumin, thymol, and eugenol oils as complementary and alternative therapies for combating MDR and multi-virulent E. coli isolates. KEY POINTS: • Our promising results confirmed that we were right for renewed interest of EOs. • The EOs, especially curcumin, can be used to prevent treatment failure. • We supposed a new pharmaceutical formulation of antibiotic powders dissolved in EOs.

Characterization of the Anti-Biofilm and Anti-Quorum Sensing Activities of the ß-Adrenoreceptor Antagonist Atenolol against Gram-Negative Bacterial Pathogens.

The development of bacterial resistance to antibiotics is an increasing public health issue that worsens with the formation of biofilms. Quorum sensing (QS) orchestrates the bacterial virulence and controls the formation of biofilm. Targeting bacterial virulence is promising approach to overcome the resistance increment to antibiotics. In a previous detailed in silico study, the anti-QS activities of twenty-two ß-adrenoreceptor blockers were screened supposing atenolol as a promising candidate. The current study aims to evaluate the anti-QS, anti-biofilm and anti-virulence activities of the ß-adrenoreceptor blocker atenolol against Gram-negative bacteria Serratia marcescens, Pseudomonas aeruginosa, and Proteus mirabilis. An in silico study was conducted to evaluate the binding affinity of atenolol to S. marcescens SmaR QS receptor, P. aeruginosa QscR QS receptor, and P. mirabilis MrpH adhesin. The atenolol anti-virulence activity was evaluated against the tested strains in vitro and in vivo. The present finding shows considerable ability of atenolol to compete with QS proteins and significantly downregulated the expression of QS- and virulence-encoding genes. Atenolol showed significant reduction in the tested bacterial biofilm formation, virulence enzyme production, and motility. Furthermore, atenolol significantly diminished the bacterial capacity for killing and protected mice. In conclusion, atenolol has potential anti-QS and anti-virulence activities against S. marcescens, P. aeruginosa, and P. mirabilis and can be used as an adjuvant in treatment of aggressive bacterial infections.

Advances in Fungal Phenaloenones-Natural Metabolites with Great Promise: Biosynthesis, Bioactivities, and an In Silico Evaluation of Their Potential as Human Glucose Transporter 1 Inhibitors.

Phenaloenones are structurally unique aromatic polyketides that have been reported in both microbial and plant sources. They possess a hydroxy perinaphthenone three-fused-ring system and exhibit diverse bioactivities, such as cytotoxic, antimicrobial, antioxidant, and anti-HIV properties, and tyrosinase, α-glucosidase, lipase, AchE (acetylcholinesterase), indoleamine 2,3-dioxygenase 1, angiotensin-I-converting enzyme, and tyrosine phosphatase inhibition. Moreover, they have a rich nucleophilic nucleus that has inspired many chemists and biologists to synthesize more of these related derivatives. The current review provides an overview of the reported phenalenones with a fungal origin, including their structures, sources, biosynthesis, and bioactivities. Moreover, more than 135 metabolites have been listed, and 71 references have been cited. SuperPred, an artificial intelligence (AI) webserver, was used to predict the potential targets for selected phenalenones. Among these targets, we chose human glucose transporter 1 (hGLUT1) for an extensive in silico study, as it shows high probability and model accuracy. Among them, aspergillussanones C (60) and G (60) possessed the highest negative docking scores of -15.082 and -14.829 kcal/mol, respectively, compared to the native inhibitor of 5RE (score: -11.206 kcal/mol). The MD (molecular dynamics) simulation revealed their stability in complexes with GLUT1 at 100 ns. The virtual screening study results open up a new therapeutic approach by using some phenalenones as hGLUT1 inhibitors, which might be a potential target for cancer therapy.

Bioassay Guided Isolation and Docking Studies of a Potential ß-Lactamase Inhibitor from Clutia myricoides.

Infectious diseases are the second major cause of death worldwide, and the ability to resist multiple classes of antibiotics is the key factor in enabling pathogenic organisms to survive and spread in the nosocomial environment. Unfortunately, the available ß-lactamase inhibitors are not efficient against ß-lactamase B, C, and D which necessitates discovering either broad spectrum ß-lactamase inhibitors or new ß-lactam antibiotics resistant to bacterial enzymes. In this regard, products of natural origin have prompted the disclosure of new compounds and medicinal leads. Chloroform fraction of Clutia myricoides (Soa'bor) showed a pronounced activity against extended-spectrum ß-lactamase (ESBL) strains. Bio-guided fractionation resulted in isolation of two new compounds; 2-methoxy chrysophanol (2) and Saudin-I (5) in addition to three known compounds that were identified as chrysophanol (1), stigmasterol (3) and ß-sitosterol (4). Antibacterial and anti ESBL activities of the isolated compounds were performed. No antibacterial activities were detected for any of the tested compounds. Meanwhile, compound 2 showed promising anti ESBL activity. Compound 2 has shown an obvious activity against K. pneumoniae ATCC 700603 with a marked enlargement of inhibition zones (>5mm) in combination with third generation cephalosporin antibiotics. To further understand the mechanism of action of compound 2, molecular docking was carried out against CTX-M-27 ESBL. The results showed binding site interactions strikingly different from its analogue, compound 1, allowing compound 2 to be active against ESBL. These results proposed the concomitant use of these active compounds with antibiotics that would increase their efficiency. Nevertheless, the interaction between this active compound and antibiotics should be taken into consideration. Therefore, in order to evaluate the safety of this active compound, further in vitro and in vivo toxicity assays must be carried out.

Protective anti-inflammatory activity of tovophyllin A against acute lung injury and its potential cytotoxicity to epithelial lung and breast carcinomas.

Tovophyllin A (TA) is a xanthone isolated from Garcinia mangostana L. (GM, Guttiferae) pericarps that possesses various beneficial bioactivities. However, its protective effects on acute lung injury (ALI) and lung carcinoma have not yet been explored. The current work was designed to investigate the protective potential of TA against ALI and explore the possible mechanism of action. Two different doses of TA were tested against lipopolysaccharide (LPS)-induced ALI in mice. Moreover, the cytotoxic potential of TA was assessed in epithelial lung (A549 cells) and breast (MCF7 cells) carcinomas utilizing a sulforhodamine B (SRB) assay. The results revealed that TA possessed the ability to protect against LPS-induced acute lung damage. TA attenuated LPS-induced pulmonary edema, as it lowered the protein content in the bronchoalveolar lavage fluid (BALF) and the lung W/D ratio. In addition, TA counteracted inflammatory cell infiltration into the lung tissue, as shown by the total and differential cell counts in the BALF and histopathological examination of the lungs. The oxidative burden in the pulmonary tissue was ameliorated in TA-treated animals as there were reductions in the malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) levels in the lung tissue. TA increased the levels of antioxidants such as reduced glutathione (GSH) and superoxide dismutase (SOD) in the lungs. Furthermore, TA inhibited the activation of nuclear factor-κB (NF-κB). In addition, TA had potent anti-inflammatory activity as it reduced the immunoexpression and levels of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß and IL-6. Furthermore, TA showed significantly enhanced cytotoxic activity against the MCF-7 and A549 cell lines with IC50s of 6.1 and 2.2 µM, respectively, compared to doxorubicin (IC50s of 0.41 and 0.74 µM, respectively). In conclusion, TA ameliorates LPS-induced ALI through the suppression of oxidative stress and inflammation. These findings suggest the potential use of this compound as a future treatment for ALI.

Prevalence of Helicobacter pylori Infection and Diagnostic Methods in the Middle East and North Africa Region.

Background and Objectives: Helicobacter pylori (H. pylori) infection is common worldwide and may cause gastroduodenal complications, including cancer. In this review, we examine the prevalence and distribution of various H. pylori genotypes and the risk factors for H. pylori infection, particularly in the Middle East and North Africa (MENA) region. We also introduce different global screening methods and guidelines and compare them to those currently in use in the MENA region. Materials and Methods: We searched the Google Scholar, PubMed, and Saudi Digital Library (SDL) databases for clinical trials and articles published in English. The data collection was mainly focused on MENA countries. However, for H. pylori genotypes and diagnostic methods, studies conducted in other regions or reporting global practices and guidelines were also included to allow a comparison with those in the MENA region. We also included studies examining the prevalence of H. pylori infection in healthy participants. Results: H. pylori infection is highly prevalent in the MENA region, mainly because of the accumulation of risk factors in developing countries. Herein, we highlight a lack of good quality studies on the prevalence of various H. pylori genotypes in the MENA region as well as a need for standard diagnostic methods and screening guidelines. Due to the complications associated with H. pylori, we recommend routine screening for H. pylori infection in all gastroenterology patients admitted in the MENA region. Conclusion: Concerted effort will first be required to validate affordable, non-invasive, and accurate diagnostic methods and to establish local guidelines with adapted cut-off values for the interpretation of the test results.

Mangostanaxanthone VII, a new cytotoxic xanthone from Garcinia mangostana.

Garcinia mangostana L. (the queen of fruits, mangosteen, family Guttiferae) is a wealthy source of xanthones. The CHCl3 soluble fraction of the air-dried pericarps of G. mangostana provided a new xanthone: mangostanaxanthone VII (5), along with four known xanthones: mangostanaxanthones I (1) and II (2), gartanin (3) and γ-mangostin (4). The structural verification of these metabolites was achieved by different spectral techniques, including UV, IR, 1D and 2D NMR and HRESIMS. The new metabolite was assessed for cytotoxic potential, using sulforhodamine B (SRB) assay towards the A549 and MCF-7 cancer cell lines. Moreover, its antimicrobial effects were evaluated against various bacterial and fungal strains, using agar disc diffusion assay. Mangostanaxanthone VII showed moderate cytotoxic activity against the A549 and MCF7 cell lines with IC50s 26.1 and 34.8 µM, respectively, compared with doxorubicin (0.74 and 0.41 µM, respectively).

Anti-Helicobacter, Antitubercular and Cytotoxic Activities of Scalaranes from the Red Sea Sponge Hyrtios erectus.

The Red Sea specimen of the marine sponge Hyrtios erectus (order Dictyoceratida) was found to contain scalarane-type sesterterpenes. 12-O-deacetyl-12,19-di-epi-scalarin (14), a new scalarane sesterterpenoid, along with fourteen previously-reported scalarane-type sesterterpenes (1⁻13 and 15) have been isolated. The chemical structures of the isolated compounds were elucidated on the basis of detailed 1D and 2D NMR spectral data and mass spectroscopy, as well as by comparison with reported data. The anti-Helicobacter pylori, antitubercular and cytotoxic activities of all fifteen compounds were evaluated to reveal the potency of Compounds 1, 2, 3, 4, 6, 7 and 10. Amongst these, Compounds 1, 3, 4, 6 and 10 displayed a promising bioactivity profile, possessing potent activities in the antitubercular and anti-H. pylori bioassay. Compounds 2 and 7 showed the most promising cytotoxic profile, while Compounds 1 and 10 showed a moderate cytotoxic profile against MCF-7, HCT-116 and HepG2 cell lines.

Saudi plants as a source of potential ß-lactamase inhibitors.

This study was performed to assess the potential ß-lactamase inhibitory properties of nineteen crude Saudi plant extracts belonging to eight families against extended spectrum ß-lactamase (ESßL) strains of Klebsiella pneumoniae and other medically important pathogens. A total of 276 microbial isolates of pathogenic bacteria were used in this study; only 15 of them showed decreased sensitivity to one or several of ceftazidime, aztreonam, cefotaxime or ceftriaxone, which are deemed to be possible producers of ESßL. Antibacterial activities of plant extracts were carried out against ESßL positive isolates by the disc diffusion method. The potential ESßL suppressing activities of plant extracts and prepared fractions, (chloroform and methanol), with or without antibiotic were studied by disc diffusion method. Results revealed that selected plant extracts showed no antibacterial activity against tested strains; meanwhile, only Echinops viscosus, Pulicaria arabica, Tephrosia nubica, Chrozophora oblongifolia, and Clutia myricoides showed pronounced ESßL inhibitory activities. The extracts were quantified for phenolic compounds and their antioxidant properties. Bio-guided fractionation of the active extracts revealed that the chloroform fraction of C. myricoides possess a promising ESßL inhibitory activity. The separation and the structural elucidation of the active compounds from C. myricoides will offer beneficial leads for developing ß-lactamase inhibitors.

Evaluation of the antiproliferative and cytotoxic activities of marine invertebrates-derived fungi.

The present study focuses on the evaluation of the cytotoxicity and antiproliferative activities of the organic extracts of 70 fungal strains associated with twelve Red Sea marine invertebrates. The fungal strains were obtained 10 sponges, one tunicate and one soft coral. Three different media including Sabouraud dextrose agar, malt extract agar and Czapek-Dox agar were used for the purification of the fungal isolates. The purified fungal isolates were cultured in their corresponding media (Sabouraud dextrose broth, Malt extract broth and Czapek-Dox broth) on shaker for 14 days at 26° C. After that, the cultures were lyophilized and the dried cultures were extracted with methanol. The methanolic extracts of these cultures were evaluated for their in vitro cytotoxicity and antiproliferative activities against three human cancer cell lines including breast adenocarcinoma (MCF-7), liver hepatocellular carcinoma (HepG2) and colorectal carcinoma (HCT-116). Nine extracts displayed potent and selective activity against MCF-7 with IC50 4.96-8.28µ g/mL without any significant effect on the other two cell lines. In addition, six extracts showed strong and selective activity against MCF-7 with IC50 11.37-15.53µ g/mL. On the other hand, most of the fungal extracts were inactive or weakly active against HepG2 and HCT-116.

Exploring antiproliferative activities and kinase profile of ortho-substituted N-(4-(2-(benzylamino)-2-oxoethyl)phenyl)benzamides.

Designing kinase inhibitors that bind to the substrate site of oncogenic kinases in a promising, albeit less explored, approach to kinase inhibition as it was sought to avoid the issue of untoward off-target modulations. Our previously identified compound KAC-12 with a meta-chlorophenyl substitution was an example of this approach. While it showed confirmed inhibitory activity against cancer cells, this substitution shifted the profile of affected targets away from Src/tubulin which were seen with the parent KX-01. In this paper, we synthesized compounds with ortho-substitutions, and we investigated the effect of such substitutions on their cellular and subcellular activities. The compound N-(4-(2-(benzylamino)-2-oxoethyl)phenyl)-2-(morpholine-4-carbonyl)benzamide (4) exhibited substantial activities against cell lines such HCT116 (IC50 of 0.97 µM) and IC50 HL60 (2.84 µM). Kinase profiling showed that compound 4 trended consistently with KAC-12 as it did not affect Src, but it had more impact on members of the Src family of kinases (SFK) such as Yes, Hck, Fyn, Lck, and Lyn. Both compounds exhibited profound downregulation effects on Erk1/2 but differed on others such as GSK3α/ß and C-Jun. Collectively, this study further support to the hypothesis that small structural changes might bring higher changes in their kinome profile.

Antimicrobial and anti-virulence activities of 4-shogaol from grains of paradise against gram-negative bacteria: Integration of experimental and computational methods.

ETHNOPHARMACOLOGICAL RELEVANCE: Bacterial resistance to antibiotics is a growing global concern, highlighting the urgent need for new antimicrobial candidates. Aframomum melegueta was traditionally used for combating urinary tract and soft tissue infections, which implies its potential as an antimicrobial agent. AIM OF STUDY: This study was designed to explore the antibacterial and anti-virulence capabilities of 4-shogaol isolated from A. melegueta seeds versus gram-negative bacteria: Serratia marcescens, Klebsiella pneumoniae, Acinetobacter baumannii, and the clinically important pathogen Pseudomonas aeruginosa. MATERIALS AND METHODS: 4-Shogeol was isolated from A. melegueta seeds and its MICs were determined for Acinetobacter baumannii (ATCC-17978), Pseudomonas aeruginosa (ATCC-27853), Klebsiella pneumoniae (ATCC-700603), and Serratia marcescens clinical isolate. The anti-efflux activity and effect on the bacterial cell membrane for the compound were evaluated. Furthermore, the anti-virulence activities of the compound were evaluated. The effects of 4-shogeol at sub-MIC on bacterial motility, biofilm formation, and production of virulent enzymes and pigments were assessed. The anti-quorum sensing activities of 4-shogeol were evaluated virtually and by quantification its effect on the expression of quorum sensing encoding genes. The in vivo protection assay was conducted to evaluate the effect of 4-shogaol on the P. aeruginosa capacity to induce pathogenesis in mice. Finally, the effect of shogaol-antibiotics combination was assessed. RESULTS: The research revealed that 4-shogaol's antibacterial action primarily involves disrupting the bacterial cell membrane and efflux pumps. It also exhibited significant anti-virulence effects by reducing biofilm development and repressing virulence factors production, effectively protecting mice against P. aeruginosa infection. Furthermore, when combined with antibiotics, 4-shogaol demonstrated synergistic effects, leading to reduced minimum inhibitory concentrations (MICs) against P. aeruginosa. Its anti-virulence properties were linked to its ability to disrupt bacterial quorum sensing (QS) mechanisms, as evidenced by its interaction with QS receptors and downregulation of QS-related genes. Notably, in silico analysis indicated that 4-shogaol exhibited strong binding affinity to different P. aeruginosa QS targets. CONCLUSION: These findings suggest that 4-shogaol holds promise as an effective anti-virulence agent that can be utilized in combination with antibiotics for treating severe infections caused by gram-positive bacteria.

RETRACTED: Alhakamy et al. Development and Optimization of Luliconazole Spanlastics to Augment the Antifungal Activity against Candida albicans. Pharmaceutics 2021, 13, 977.

The journal retracts the article, "Development and Optimization of Luliconazole Spanlastics to Augment the Antifungal Activity against Candida albicans" [...].