scholarly journals In Vitro Antifungal Activity and Cytotoxicity of a Novel Membrane-Active Peptide

1999 ◽  
Vol 43 (7) ◽  
pp. 1704-1707 ◽  
Author(s):  
Sung Yu Hong ◽  
Jong Eun Oh ◽  
Keun Hyeung Lee

ABSTRACT In the present study, we investigated the antifungal activity and cytotoxicity of a novel membrane-active peptide, KKVVFKVKFKK (MP). MP inhibited the growth of various pathogenic fungi isolated from patients and of fluconazole-resistant fungi at concentrations of 2 to 32 μg/ml. MP had potent fungicidal activity; the minimal fungicidal concentrations of the peptide were no more than fourfold greater than the MICs. Time course experiments of MP-induced killing of Candida albicans ATCC 36232 showed that the rate of killing was rapid and depended on the concentration of MP. MP had a strong synergism with other antifungal drugs; the fractional inhibitory concentration index values of MP with amphotericin B and fluconazole for C. albicans were 0.16 and 0.02, respectively. The 50% inhibitory concentrations of MP for NIH 3T3 and Jurkat cells were approximately 100 times higher than the MIC for C. albicansATCC 36232, indicating that MP had high selectivity between the fungal and mammalian cells. These results suggest that MP has great advantages in the development of antifungal agents.

1999 ◽  
Vol 43 (12) ◽  
pp. 2862-2868 ◽  
Author(s):  
Maurizio Del Poeta ◽  
Shih-Fong Chen ◽  
Daniel Von Hoff ◽  
Christine C. Dykstra ◽  
Mansukh C. Wani ◽  
...  

ABSTRACT The activities of a series of camptothecin and nitidine derivatives that might interact with topoisomerase I were compared against yeast and cancer cell lines. Our findings reveal that structural modifications to camptothecin derivatives have profound effects on the topoisomerase I-drug poison complex in cells. Although the water-soluble anticancer agents topotecan and irinotecan are less active than the original structure, camptothecin, other derivatives or analogs with substitutions that increase compound solubility have also increased antifungal activities. In fact, a water-soluble prodrug appears to penetrate into the cell and release its active form; the resulting effect in complex with Cryptococcus neoformanstopoisomerase I is a fungicidal response and also potent antitumor activity. Some of the compounds that are not toxic to wild-type yeast cells are extremely toxic to the yeast cells when the C. neoformans topoisomerase I target is overexpressed. With the known antifungal mechanism of a camptothecin-topoisomerase I complex as a cellular poison, these findings indicate that drug entry may be extremely important for antifungal activity. Nitidine chloride exhibits antifungal activity against yeast cells through a mechanism(s) other than topoisomerase I and appears to be less active than camptothecin analogs against tumor cells. Finally, some camptothecin analogs exhibit synergistic antifungal activity against yeast cells in combination with amphotericin B in vitro. Our results suggest that camptothecin and/or nitidine derivatives can exhibit potent antifungal activity and that the activities of camptothecin derivatives with existing antifungal drugs may be synergistic against pathogenic fungi. These new compounds, which exhibit potent antitumor activities, will likely require further structural changes to find more selective activity against fungal versus mammalian cells to hold promise as a new class of antifungal agents.


2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Yeonseon Lee ◽  
Kyung-Tae Lee ◽  
Soo Jung Lee ◽  
Ji Yoon Beom ◽  
Areum Hwangbo ◽  
...  

ABSTRACT FK506 (tacrolimus) is an FDA-approved immunosuppressant indicated for the prevention of allograft rejections in patients undergoing organ transplants. In mammals, FK506 inhibits the calcineurin-nuclear factor of activated T cells (NFAT) pathway to prevent T-cell proliferation by forming a ternary complex with its binding protein, FKBP12, and calcineurin. FK506 also exerts antifungal activity by inhibiting calcineurin, which is essential for the virulence of human-pathogenic fungi. Nevertheless, FK506 cannot be used directly as an antifungal drug due to its immunosuppressive action. In this study, we analyzed the cytotoxicity, immunosuppressive activity, and antifungal activity of four FK506 analogs, 31-O-demethyl-FK506, 9-deoxo-FK506, 9-deoxo-31-O-demethyl-FK506, and 9-deoxo-prolyl-FK506, in comparison with that of FK506. The four FK506 analogs generally possessed lower cytotoxicity and immunosuppressive activity than FK506. The FK506 analogs, except for 9-deoxo-prolyl-FK506, had strong antifungal activity against Cryptococcus neoformans and Candida albicans, which are two major invasive pathogenic yeasts, due to the inhibition of the calcineurin pathway. Furthermore, the FK506 analogs, except for 9-deoxo-prolyl-FK506, had strong antifungal activity against the invasive filamentous fungus Aspergillus fumigatus. Notably, 9-deoxo-31-O-demethyl-FK506 and 31-O-demethyl-FK506 exhibited robust synergistic antifungal activity with fluconazole, similar to FK506. Considering the antifungal efficacy, cytotoxicity, immunosuppressive activity, and synergistic effect with commercial antifungal drugs, we selected 9-deoxo-31-O-demethyl-FK506 for further evaluation of its in vivo antifungal efficacy in a murine model of systemic cryptococcosis. Although 9-deoxo-31-O-demethyl-FK506 alone was not sufficient to treat the cryptococcal infection, when it was used in combination with fluconazole, it significantly extended the survival of C. neoformans-infected mice, confirming the synergistic in vivo antifungal efficacy between these two agents.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benjamin N. Nelson ◽  
Savannah G. Beakley ◽  
Sierra Posey ◽  
Brittney Conn ◽  
Emma Maritz ◽  
...  

AbstractCryptococcal meningitis is a life-threatening disease among immune compromised individuals that is caused by the opportunistic fungal pathogen Cryptococcus neoformans. Previous studies have shown that the fungus is phagocytosed by dendritic cells (DCs) and trafficked to the lysosome where it is killed by both oxidative and non-oxidative mechanisms. While certain molecules from the lysosome are known to kill or inhibit the growth of C. neoformans, the lysosome is an organelle containing many different proteins and enzymes that are designed to degrade phagocytosed material. We hypothesized that multiple lysosomal components, including cysteine proteases and antimicrobial peptides, could inhibit the growth of C. neoformans. Our study identified the contents of the DC lysosome and examined the anti-cryptococcal properties of different proteins found within the lysosome. Results showed several DC lysosomal proteins affected the growth of C. neoformans in vitro. The proteins that killed or inhibited the fungus did so in a dose-dependent manner. Furthermore, the concentration of protein needed for cryptococcal inhibition was found to be non-cytotoxic to mammalian cells. These data show that many DC lysosomal proteins have antifungal activity and have potential as immune-based therapeutics.


1989 ◽  
Vol 262 (2) ◽  
pp. 449-456 ◽  
Author(s):  
C Hanekom ◽  
A Nel ◽  
C Gittinger ◽  
A Rheeder ◽  
G Landreth

Treatment of Jurkat T-cells with anti-CD-3 monoclonal antibodies resulted in the rapid and transient activation of a serine kinase which utilized the microtubule-associated protein, MAP-2, as a substrate in vitro. The kinase was also activated on treatment of Jurkat cells with phytohaemagglutinin, but with a different time course. The activation of the MAP-2 kinase by anti-CD-3 antibodies was dose-dependent, with maximal activity observed at concentrations of greater than 500 ng/ml. Normal human E-rosette-positive T-cells also exhibited induction of MAP-2 kinase activity during anti-CD-3 treatment. The enzyme was optimally active in the presence of 2 mM-Mn2+; lower levels of activity were observed with Mg2+, even at concentrations up to 20 mM. The kinase was partially purified by passage over DE-52 Sephacel with the activity eluting as a single peak at 0.25 M-NaCl. The molecular mass was estimated to be 45 kDa by gel filtration. The activation of the MAP-2 kinase was probably due to phosphorylation of this enzyme as treatment with alkaline phosphatase diminished its activity. These data demonstrate that the stimulation of T-cells through the CD-3 complex results in the activation of a novel serine kinase which may be critically involved in signal transduction in these cells.


2019 ◽  
Vol 41 (3) ◽  
pp. 549-549
Author(s):  
Xuesong Wang and Xiaorong Tang Xuesong Wang and Xiaorong Tang

A series of novel benzamide derivatives according to fluopicolide were designed and synthesized following the rule of combination carboxylic acid amides and amines derivatives together. The antifungal activity of the 15 new compounds were evaluated in vitro against five pathogenic fungi, including Sclerotinia sclerotiorum, Gibberella zeae, Rhizoctonia solani, Helminthosporium maydis and Botrytis cinerea. Almost all the structure have not been reported, except compounds 3, 5 and 6. A surprising finding is that all the five tested fungi breed faster than negative controls when supplementary with compound 715 , respectively.


2001 ◽  
Vol 8 (3) ◽  
pp. 165-169 ◽  
Author(s):  
A. Smicka ◽  
V. Buchta ◽  
K. Handlir

Six new N-substituted di- and tributyltin 2-aminoethanethiolates (cysteaminates) have been prepared and characterised by H1, C13 and S119n NMR spectroscopy. All these compounds exhibit a good in vitro antifungal effect against selected types of human pathogenic fungi (Candida albicans, Candida krusei, Candida tropicalis, Candida glabrata, Trichosporon beigelii, Aspergillus fumigatus, Absidia corymbifera, Trichophyton mentagrophytes) and their activity is comparable with that of some antifungal drugs commonly used in the clinical use like ketoconazole. The structure-activity relationships in these compounds are discussed.


mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Eric H. Jung ◽  
David J. Meyers ◽  
Jürgen Bosch ◽  
Arturo Casadevall

ABSTRACTSimilarities in fungal and animal cells make antifungal discovery efforts more difficult than those for other classes of antimicrobial drugs. Currently, there are only three major classes of antifungal drugs used for the treatment of systemic fungal diseases: polyenes, azoles, and echinocandins. Even in situations where the offending fungal organism is susceptible to the available drugs, treatment courses can be lengthy and unsatisfactory, since eradication of infection is often very difficult, especially in individuals with impaired immunity. Consequently, there is a need for new and more effective antifungal drugs. We have identified compounds with significant antifungal activity in the Malaria Box (Medicines for Malaria Ventures, Geneva, Switzerland) that have higher efficacy than some of the currently used antifungal drugs. Our best candidate, MMV665943 (IUPAC name 4-[6-[[2-(4-aminophenyl)-3H-benzimidazol-5-yl]methyl]-1H-benzimidazol-2-yl]aniline), here referred to as DM262, showed 16- to 32-fold-higher activity than fluconazole againstCryptococcus neoformans. There was also significant antifungal activity in other fungal species with known antifungal resistance, such asLomentospora prolificansandCryptococcus gattii. Antifungal activity was also observed against a common fungus,Candida albicans. These results are important because they offer a potentially new class of antifungal drugs and the repurposing of currently available therapeutics.IMPORTANCEMuch like the recent increase in drug-resistant bacteria, there is a rise in antifungal-resistant strains of pathogenic fungi. There is a need for novel and more potent antifungal therapeutics. Consequently, we investigated a mixed library of drug-like and probe-like compounds with activity inPlasmodiumspp. for activity against two common fungal pathogens,Cryptococcus neoformansandCandida albicans, along with two less common pathogenic species,Lomentospora prolificansandCryptococcus gattii. We uncover a previously uncharacterized drug with higher broad-spectrum antifungal activity than some current treatments. Our findings may eventually lead to a compound added to the arsenal of antifungal therapeutics.


2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Cristina Lazzarini ◽  
Krupanandan Haranahalli ◽  
Robert Rieger ◽  
Hari Krishna Ananthula ◽  
Pankaj B. Desai ◽  
...  

ABSTRACTThe incidence of invasive fungal infections has risen dramatically in recent decades. Current antifungal drugs are either toxic, likely to interact with other drugs, have a narrow spectrum of activity, or induce fungal resistance. Hence, there is a great need for new antifungals, possibly with novel mechanisms of action. Previously our group reported an acylhydrazone called BHBM that targeted the sphingolipid pathway and showed strong antifungal activity against several fungi. In this study, we screened 19 derivatives of BHBM. Three out of 19 derivatives were highly active againstCryptococcus neoformansin vitroand had low toxicity in mammalian cells. In particular, one of them, called D13, had a high selectivity index and showed better activity in an animal model of cryptococcosis, candidiasis, and pulmonary aspergillosis. D13 also displayed suitable pharmacokinetic properties and was able to pass through the blood-brain barrier. These results suggest that acylhydrazones are promising molecules for the research and development of new antifungal agents.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Tamirat Bekele Beressa ◽  
Serawit Deyno ◽  
Paul E. Alele

Background. Echinops kebericho is an endemic medicinal plant in Ethiopia widely used in the treatment of infectious and noninfectious diseases. Essential oils are known for their antibacterial, antifungal, antiviral, insecticidal, and antioxidant properties. This study evaluated the antifungal activity of essential oil from E. kebericho against four common pathogenic fungi and two standard strains. Methods. The essential oil was obtained by hydrodistillation. The antifungal screening was done by agar well diffusion method. Minimal inhibitory concentrations (MICs) were determined by broth microdilution. Minimal fungicidal concentrations (MFCs) were determined by subculturing fungal strains with no visible growth onto a Sabouraud dextrose agar (SDA) plate. Results. Candida albicans and Cryptococcus neoformans were highly sensitive while Aspergillus flavus did not show sensitivity up to 1 mg/ml of essential oil; MICs ranged from 0.083 mg/ml to 0.208 mg/ml. Concentration and fungal species showed significant dose-dependent associations ( p < 0.0001 ) with antifungal activity. The MICs of essential oil were comparable to those of the standard drug (fluconazole) against C. glabrata and C. krusei. The lowest MFC of the essential oil was observed against Candida parapsilosis (0.145 mg/ml) while the highest MFC was against Candida krusei (0.667 mg/ml). Conclusion. Echinops kebericho essential oil showed noteworthy antifungal activity against Cryptococcus neoformans, Candida albicans, and Candida glabrata and could be a potential candidate for further antifungal drug development.


2020 ◽  
Vol 21 (21) ◽  
pp. 7912 ◽  
Author(s):  
Tatyana Odintsova ◽  
Larisa Shcherbakova ◽  
Marina Slezina ◽  
Tatyana Pasechnik ◽  
Bakhyt Kartabaeva ◽  
...  

Hevein-like antimicrobial peptides (AMPs) comprise a family of plant AMPs with antifungal activity, which harbor a chitin-binding site involved in interactions with chitin of fungal cell walls. However, the mode of action of hevein-like AMPs remains poorly understood. This work reports the structure–function relationship in WAMPs—hevein-like AMPs found in wheat (Triticum kiharae Dorof. et Migush.) and later in other Poaceae species. The effect of WAMP homologues differing at position 34 and the antifungal activity of peptide fragments derived from the central, N- and C-terminal regions of one of the WAMPs, namely WAMP-2, on spore germination of different plant pathogenic fungi were studied. Additionally, the ability of WAMP-2-derived peptides to potentiate the fungicidal effect of tebuconazole, one of the triazole fungicides, towards five cereal-damaging fungi was explored in vitro by co-application of WAMP-2 fragments with Folicur® EC 250 (25% tebuconazole). The antifungal activity of WAMP homologues and WAMP-2-derived peptides varied depending on the fungus, suggesting multiple modes of action for WAMPs against diverse pathogens. Folicur® combined with the WAMP-2 fragments inhibited the spore germination at a much greater level than the fungicide alone, and the type of interactions was either synergistic or additive, depending on the target fungus and concentration combinations of the compounds. The combinations, which resulted in synergism and drastically enhanced the sensitivity to tebuconazole, were revealed for all five fungi by a checkerboard assay. The ability to synergistically interact with a fungicide and exacerbate the sensitivity of plant pathogenic fungi to a commercial antifungal agent is a novel and previously uninvestigated property of hevein-like AMPs.


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