scholarly journals Antifungal Activity and Potential Mechanism of 6,7, 4′-O-Triacetylscutellarein Combined With Fluconazole Against Drug-Resistant C. albicans

2021 ◽  
Vol 12 ◽  
Author(s):  
Liu-Yan Su ◽  
Guang-Hui Ni ◽  
Yi-Chuan Liao ◽  
Liu-Qing Su ◽  
Jun Li ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Signaling Pathway ◽  
Treatment Method ◽  
Inhibitory Effect ◽  
Antifungal Drugs ◽  
Infection Model ◽  
Drug Resistant ◽  
Mycelium Growth

The increased resistance of Candida albicans to conventional antifungal drugs poses a huge challenge to the clinical treatment of this infection. In recent years, combination therapy, a potential treatment method to overcome C. albicans resistance, has gained traction. This study assessed the effect of 6,7,4′-O-triacetylscutellarein (TA) combined with fluconazole (FLC) on C. albicans in vitro and in vivo. TA combined with FLC showed good synergistic antifungal activity against drug-resistant C. albicans in vitro, with a partial inhibitory concentration index (FICI) of 0.0188–0.1800. In addition, the time-kill curve confirmed the synergistic effect of TA and FLC. TA combined with FLC showed a strong synergistic inhibitory effect on the biofilm formation of resistant C. albicans. The combined antifungal efficacy of TA and FLC was evaluated in vivo in a mouse systemic fungal infection model. TA combined with FLC prolonged the survival rate of mice infected with drug-resistant C. albicans and reduced tissue invasion. TA combined with FLC also significantly inhibited the yeast-hypha conversion of C. albicans and significantly reduced the expression of RAS-cAMP-PKA signaling pathway-related genes (RAS1 and EFG1) and hyphal-related genes (HWP1 and ECE1). Furthermore, the mycelium growth on TA combined with the FLC group recovered after adding exogenous db-cAMP. Collectively, these results show that TA combined with FLC inhibits the formation of hyphae and biofilms through the RAS-cAMP-PKA signaling pathway, resulting in reduced infectivity and resistance of C. albicans. Therefore, this study provides a basis for the treatment of drug-resistant C. albicans infections.

scholarly journals Reversal of Azole Resistance inCandida albicansby Sulfa Antibacterial Drugs

2017 ◽  
Vol 62 (3) ◽  
Author(s):  
Hassan E. Eldesouky ◽  
Abdelrahman Mayhoub ◽  
Tony R. Hazbun ◽  
Mohamed N. Seleem
Keyword(s):  
Treatment Options ◽  
Antifungal Drugs ◽  
Infection Model ◽  
Azole Resistance ◽  
Global Public Health ◽  
Sulfa Drugs ◽  
Antibacterial Drugs ◽  
Content Type

ABSTRACTInvasive candidiasis presents an emerging global public health challenge due to the emergence of resistance to the frontline treatment options, such as fluconazole. Hence, the identification of other compounds capable of pairing with fluconazole and averting azole resistance would potentially prolong the clinical utility of this important group. In an effort to repurpose drugs in the field of antifungal drug discovery, we explored sulfa antibacterial drugs for the purpose of reversing azole resistance inCandida. In this study, we assembled and investigated a library of 21 sulfa antibacterial drugs for their ability to restore fluconazole sensitivity inCandida albicans. Surprisingly, the majority of assayed sulfa drugs (15 of 21) were found to exhibit synergistic relationships with fluconazole by checkerboard assay with fractional inhibitory concentration index (ΣFIC) values ranging from <0.0312 to 0.25. Remarkably, five sulfa drugs were able to reverse azole resistance in a clinically achievable range. The structure-activity relationships (SARs) of the amino benzene sulfonamide scaffold as antifungal agents were studied. We also identified the possible mechanism of the synergistic interaction of sulfa antibacterial drugs with azole antifungal drugs. Furthermore, the ability of sulfa antibacterial drugs to inhibitCandidabiofilm by 40%in vitrowas confirmed. In addition, the effects of sulfa-fluconazole combinations onCandidagrowth kinetics and efflux machinery were explored. Finally, using aCaenorhabditis elegansinfection model, we demonstrated that the sulfa-fluconazole combination does possess potent antifungal activityin vivo, reducingCandidain infected worms by ∼50% compared to the control.

scholarly journals Activity of the Pore-Forming Virulence Factor Listeriolysin O Is Reversibly Inhibited by Naturally Occurring S-Glutathionylation

2017 ◽  
Vol 85 (4) ◽  
Author(s):  
Jonathan L. Portman ◽  
Qiongying Huang ◽  
Michelle L. Reniere ◽  
Anthony T. Iavarone ◽  
Daniel A. Portnoy
Keyword(s):  
Protein Function ◽  
Inhibitory Effect ◽  
Cysteine Residue ◽  
Infection Model ◽  
Listeriolysin O ◽  
Content Type ◽  
Pore Forming Proteins

ABSTRACT Cholesterol-dependent cytolysins (CDCs) represent a family of homologous pore-forming proteins secreted by many Gram-positive bacterial pathogens. CDCs mediate membrane binding partly through a conserved C-terminal undecapeptide, which contains a single cysteine residue. While mutational changes to other residues in the undecapeptide typically have severe effects, mutation of the cysteine residue to alanine has minor effects on overall protein function. Thus, the role of this highly conserved reactive cysteine residue remains largely unknown. We report here that the CDC listeriolysin O (LLO), secreted by the facultative intracellular pathogen Listeria monocytogenes, was posttranslationally modified by S-glutathionylation at this conserved cysteine residue and that either endogenously synthesized or exogenously added glutathione was sufficient to form this modification. When recapitulated with purified protein in vitro, this modification completely ablated the activity of LLO, and this inhibitory effect was fully reversible by treatment with reducing agents. A cysteine-to-alanine mutation in LLO rendered the protein completely resistant to inactivation by S-glutathionylation, and a mutant expressing this mutation retained full hemolytic activity. A mutant strain of L. monocytogenes expressing the cysteine-to-alanine variant of LLO was able to infect and replicate within bone marrow-derived macrophages indistinguishably from the wild type in vitro, yet it was attenuated 4- to 6-fold in a competitive murine infection model in vivo. This study suggests that S-glutathionylation may represent a mechanism by which CDC-family proteins are posttranslationally modified and regulated and help explain an evolutionary pressure to retain the highly conserved undecapeptide cysteine.

scholarly journals Synergistic Antifungal Activity of Chitosan with Fluconazole against Candida albicans, Candida tropicalis, and Fluconazole-Resistant Strains

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5114
Author(s):  
Wei-Hsuan Lo ◽  
Fu-Sheng Deng ◽  
Chih-Jung Chang ◽  
Ching-Hsuan Lin
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Candida Tropicalis ◽  
Inhibitory Effect ◽  
Antifungal Drugs ◽  
Drug Resistant ◽  
Combinational Treatment ◽  
Fluconazole Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

(1) Background: Few antifungal drugs are currently available, and drug-resistant strains have rapidly emerged. Thus, the aim of this study is to evaluate the effectiveness of the antifungal activity from a combinational treatment of chitosan with a clinical antifungal drug on Candida albicans and Candida tropicalis. (2) Methods: Minimum inhibitory concentration (MIC) tests, checkerboard assays, and disc assays were employed to determine the inhibitory effect of chitosan with or without other antifungal drugs on C. albicans and C. tropicalis. (3) Results: Treatment with chitosan in combination with fluconazole showed a great synergistic fungicidal effect against C. albicans and C. tropicalis, but an indifferent effect on antifungal activity when challenged with chitosan-amphotericin B or chitosan-caspofungin simultaneously. Furthermore, the combination of chitosan and fluconazole was effective against drug-resistant strains. (4) Conclusions: These findings provide strong evidence that chitosan in combination with fluconazole is a promising therapy against two Candida species and its drug-resistant strains.

scholarly journals RPN2 is targeted by miR-181c and mediates glioma progression and temozolomide sensitivity via the wnt/β-catenin signaling pathway

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Jikui Sun ◽  
Quanfeng Ma ◽  
Banban Li ◽  
Chen Wang ◽  
Lidong Mo ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Glycogen Synthase ◽  
Inhibitory Effect ◽  
Who Grade ◽  
Pathway Network ◽  
Mechanistic Investigation ◽  
Signaling Axis ◽  
Gsk 3Β

Abstract Accumulating evidence indicates that the dysregulation of the miRNAs/mRNA-mediated carcinogenic signaling pathway network is intimately involved in glioma initiation and progression. In the present study, by performing experiments and bioinformatics analysis, we found that RPN2 was markedly elevated in glioma specimens compared with normal controls, and its upregulation was significantly linked to WHO grade and poor prognosis. Knockdown of RPN2 inhibited tumor proliferation and invasion, promoted apoptosis, and enhanced temozolomide (TMZ) sensitivity in vitro and in vivo. Mechanistic investigation revealed that RPN2 deletion repressed β-catenin/Tcf-4 transcription activity partly through functional activation of glycogen synthase kinase-3β (GSK-3β). Furthermore, we showed that RPN2 is a direct functional target of miR-181c. Ectopic miR-181c expression suppressed β-catenin/Tcf-4 activity, while restoration of RPN2 partly reversed this inhibitory effect mediated by miR-181c, implying a molecular mechanism in which TMZ sensitivity is mediated by miR-181c. Taken together, our data revealed a new miR-181c/RPN2/wnt/β-catenin signaling axis that plays significant roles in glioma tumorigenesis and TMZ resistance, and it represents a potential therapeutic target, especially in GBM.

scholarly journals Tridecaptin M, a New Variant Discovered in Mud Bacterium, Shows Activity against Colistin- and Extremely Drug-ResistantEnterobacteriaceae

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Manoj Jangra ◽  
Manpreet Kaur ◽  
Rushikesh Tambat ◽  
Rohit Rana ◽  
Sushil K. Maurya ◽  
...  
Keyword(s):  
Hemolytic Activity ◽  
World Health ◽  
Fourth Generation ◽  
Infection Model ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
New Variant

ABSTRACTThe World Health Organization has categorized the Gram-negative superbugs, which are inherently impervious to many antibiotics, as critical priority pathogens due to the lack of effective treatments. The breach in our last-resort antibiotic (i.e., colistin) by extensively drug-resistant and pan-drug-resistantEnterobacteriaceaestrains demands the immediate development of new therapies. In the present study, we report the discovery of tridecaptin M, a new addition to the family, and its potential against colistin-resistantEnterobacteriaceae in vitroandin vivo. Also, we performed mode-of-action studies using various fluorescent probes and studied the hemolytic activity and mammalian cytotoxicity in two cell lines. Tridecaptin M displayed strong antibacterial activity (MICs of 2 to 8 μg ml−1) against clinical strains ofKlebsiella pneumoniae(which were resistant to colistin, carbapenems, third- and fourth-generation cephalosporins, fluoroquinolones, fosfomycin, and other antibiotics) andmcr-1-positiveEscherichia colistrains. Unlike polymyxins, tridecaptin M did not permeabilize the outer membrane or cytoplasmic membrane. It blocked ATP synthesis in bacteria by dissipating the proton motive force. The compound exhibited negligible acquired resistance, lowin vitrocytotoxicity and hemolytic activity, and no significant acute toxicity in mice. It also showed promising efficacy in a thigh infection model of colistin-resistantK. pneumoniae. Altogether, these results demonstrate the future prospects of this class of antibiotics to address the unmet medical need to circumvent colistin resistance in extensively drug-resistantEnterobacteriaceaeinfections. The work also emphasizes the importance of natural products in our shrunken drug discovery pipeline.

scholarly journals Hope in the Treatment of Candida Vaginitis: Ibrexafungerp

2021 ◽  
Author(s):  
Ayşe Sultan Karakoyun
Keyword(s):  
Current Knowledge ◽  
Public Health Problem ◽  
Clinical Findings ◽  
Antifungal Drugs ◽  
Drug Resistant ◽  
Over The Counter ◽  
Synthase Inhibitor ◽  
Increased Activity

Candida vaginitis (CV) is a neglected but growing public health problem. It is estimated that three out of four women have had at least one CV attack. The diagnosis and treatment of CV is often inadequate due to the tendency of women to self-diagnose and use over-the-counter drugs when they have vaginal or vulvar complaints, and clinicians plan treatment only according to clinical findings. There are limitations regarding the safety and efficacy of oral azoles, which are primarily preferred for the treatment of vaginitis, and these drugs have not revealed the desired levels of clinical or mycological cure. Also, there are a few options for current drugs used for treatment are not numerous the development of new antifungal drugs is thus urgently needed. Ibrexafungerp (IBX) is a semisynthetic triterpenoid glucan synthase inhibitor derived from enfumafungin. IBX has been shown to be a promising oral antifungal in the treatment of acute CV, and its use was approved on June 1, 2021. IBX is remarkable by it’s high oral bioavailability, low risk of side effects, few drug-drug interactions, good tissue penetration, increased activity at low pH in the vagina, and efficacy with regard to multi-drug-resistant fungi. In this review, in vitro and in vivo data on IBX were evaluated and compiled in light of current knowledge.

scholarly journals Effects of Origanum vulgare essential oil and its two main components, carvacrol and thymol, on the plant pathogen Botrytis cinerea

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9626
Author(s):  
Huiyu Hou ◽  
Xueying Zhang ◽  
Te Zhao ◽  
Lin Zhou
Keyword(s):  
Antifungal Activity ◽  
Essential Oil ◽  
Botrytis Cinerea ◽  
Spore Germination ◽  
Gray Mold ◽  
Origanum Vulgare ◽  
Mycelium Growth ◽  
Main Components

Background Botrytis cinerea causes serious gray mold disease in many plants. This pathogen has developed resistance to many fungicides. Thus, it has become necessary to look for new safe yet effective compounds against B. cinerea. Methods Essential oils (EOs) from 17 plant species were assayed against B. cinerea, of which Origanum vulgare essential oil (OVEO) showed strong antifungal activity, and accordingly its main components were detected by GC/MS. Further study was conducted on the effects of OVEO, carvacrol and thymol in vitro on mycelium growth and spore germination, mycelium morphology, leakages of cytoplasmic contents, mitochondrial injury and accumulation of reactive oxygen species (ROS) of B. cinerea. The control efficacies of OVEO, carvacrol and thymol on tomato gray mold were evaluated in vivo. Results Of all the 17 plant EOs tested, Cinnamomum cassia, Litsea cubeba var. formosana and O. vulgare EOs had the best inhibitory effect on B. cinerea, with 0.5 mg/mL completely inhibiting the mycelium growth of B. cinerea. Twenty-one different compounds of OVEO were identified by gas chromatography–mass spectrometry, and the main chemical components were carvacrol (89.98%), β-caryophyllene (3.34%), thymol (2.39%), α-humulene (1.38%) and 1-methyl-2-propan-2-ylbenzene isopropyl benzene (1.36%). In vitro experiment showed EC50 values of OVEO, carvacrol and thymol were 140.04, 9.09 and 21.32 μg/mL, respectively. Carvacrol and thymol completely inhibited the spore germination of B. cinerea at the concentration of 300 μg/mL while the inhibition rate of OVEO was 80.03%. EC50 of carvacrol and thymol have significantly (P < 0.05) reduced the fresh and dry weight of mycelia. The collapse and damage on B. cinerea mycelia treated with 40 μg/mL of carvacrol and thymol was examined by scanning electron microscope (SEM). Through extracellular conductivity test and fluorescence microscope observation, it was found that carvacrol and thymol led to increase the permeability of target cells, the destruction of mitochondrial membrane and ROS accumulation. In vivo conditions, 1000 μg/mL carvacrol had the best protective and therapeutic effects on tomato gray mold (77.98% and 28.04%, respectively), and the protective effect was significantly higher than that of 400 μg/mL pyrimethanil (43.15%). While the therapeutic and protective effects of 1,000 μg/mL OVEO and thymol were comparable to chemical control. Conclusions OVEO showed moderate antifungal activity, whereas its main components carvacrol and thymol have great application potential as natural fungicides or lead compounds for commercial fungicides in preventing and controlling plant diseases caused by B. cinerea.

scholarly journals YTHDF2 Inhibits Gastric Cancer Cell Growth by Regulating FOXC2 Signaling Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Xudong Shen ◽  
Kui Zhao ◽  
Liming Xu ◽  
Guilian Cheng ◽  
Jianhong Zhu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Patient ◽  
Signaling Pathway ◽  
Inhibitory Effect ◽  
Signal Pathways ◽  
Gastric Cancer Cells ◽  
Cancer Cell Growth ◽  
Patient Prognosis

BackgroundGastric cancer (GC) is one of the most common malignancies in the world, and the fourth most frequent malignancy worldwide. YTHDF2 (YTH domain family 2, YTHDF2) binds to mRNA containing m6A, thereby regulating the localization and stability of the bound mRNA. YTHDF2 was shown to be associated with some cancer patient prognosis. However, the effect of YTHDF2 on gastric cancer and the molecular mechanism of this effect have not been documented.MethodsTo conduct this research, YTHDF2 expression levels in public databases and gastric cancer patient samples were analyzed. The effects of YTHDF2 on the growth of gastric cancer cells were detected in vivo and in vitro. RNA-seq was used to analyze the signal pathways regulated by YTHDF2, and experiments were carried out for verification.ResultsIn our study, we found that YTHDF2 has lower expression in GC tissues and GC cells, and inhibits the growth of GC cells. In addition, the analysis of clinical data found that the expression level of YTHDF2 is closely related to the stage of GC and the survival of patients with GC. RNA sequencing results showed that overexpression of YTHDF2 significantly reduced protein expression in the FOXC2 (Forkhead box protein C2, FOXC2) signaling pathway. Finally, we found that knockout of FOXC2 reversed the inhibitory effect of YTHDF2 on GC cells.ConclusionIn summary, YTHDF2 inhibits the growth of GC cells by negatively regulating FOXC2 and may serve as a prognostic marker in GC.

scholarly journals Antimicrobial Effects of Ibuprofen Combined with Standard of Care Antimicrobials against Cystic Fibrosis Pathogens

2021 ◽  
Author(s):  
Qingquan Chen ◽  
Marleini Ilanga ◽  
Sabona B Simbassa ◽  
Bhagath Chirra ◽  
Kush N Shah ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Antimicrobial Activity ◽  
Standard Of Care ◽  
Infection Model ◽  
High Dose ◽  
Synergistic Activity ◽  
Drug Resistant ◽  
Anti Inflammatory

Cystic Fibrosis (CF) is a common fatal genetic disease caused by mutations happened to cystic fibrosis transmembrane conductance regulator (CFTR) gene. Lungs of CF patients are often colonized or infected with microorganisms. Drug resistant bacterial infection has been problematic in cystic fibrosis patient. The chronic bacterial infections and concomitant airway inflammation could damage the lung and lead to respiratory failure. Several clinical trials have demonstrated that high-dose ibuprofen reduces the rate of pulmonary function decline in CF patients. This beneficial effect has been attributed to the anti-inflammatory properties of ibuprofen. Previously, we have confirmed that high-dose ibuprofen demonstrated antimicrobial activity against P. aeruginosa in in vitro and in vivo. However, no study has examined the antimicrobial effect of combining ibuprofen with standard-of-care (SoC) antimicrobials. Here, we evaluated possible synergistic activity of combinations of common nonsteroidal anti-inflammatory drugs (NSAIDs), namely, aspirin, naproxen, and ibuprofen, with commonly used antibiotics for CF patients. The drug combinations were screened against different CF clinical isolates. Drugs that demonstrated efficacy in the presence of ibuprofen were further verified synergistic effects between these antimicrobials and NSAIDs. Finally, the survival analysis of an P. aeruginosa murine infection model was used to demonstrate the efficacy of synergistic combination. Our results suggest that combinations of ibuprofen with commonly used antibiotics demonstrate synergistic antimicrobial activity against drug resistant, clinical bacterial strains in in vitro. The efficacy of combination ceftazidime and ibuprofen was demonstrated in in vivo.

scholarly journals A marine microbiome antifungal targets urgent-threat drug-resistant fungi

Science ◽  
2020 ◽  
Vol 370 (6519) ◽  
pp. 974-978 ◽  
Author(s):  
Fan Zhang ◽  
Miao Zhao ◽  
Doug R. Braun ◽  
Spencer S. Ericksen ◽  
Jeff S. Piotrowski ◽  
...  
Keyword(s):  
Mode Of Action ◽  
Fungal Pathogens ◽  
Antifungal Drugs ◽  
Multiple Drug ◽  
Drug Resistant ◽  
Candida Auris ◽  
Marine Animals ◽  
Multiple Drug Resistant

New antifungal drugs are urgently needed to address the emergence and transcontinental spread of fungal infectious diseases, such as pandrug-resistant Candida auris. Leveraging the microbiomes of marine animals and cutting-edge metabolomics and genomic tools, we identified encouraging lead antifungal molecules with in vivo efficacy. The most promising lead, turbinmicin, displays potent in vitro and mouse-model efficacy toward multiple-drug–resistant fungal pathogens, exhibits a wide safety index, and functions through a fungal-specific mode of action, targeting Sec14 of the vesicular trafficking pathway. The efficacy, safety, and mode of action distinct from other antifungal drugs make turbinmicin a highly promising antifungal drug lead to help address devastating global fungal pathogens such as C. auris.

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