Displaying all 14 publications

  1. Waghule T, Sankar S, Rapalli VK, Gorantla S, Dubey SK, Chellappan DK, et al.
    Dermatol Ther, 2020 11;33(6):e13905.
    PMID: 32588940 DOI: 10.1111/dth.13905
    The incidences of fungal infections have greatly increased over the past few years, particularly in humid and industrialized areas. The severity of such infections ranges from being asymptomatic-mild to potentially life-threatening systemic infections. There are limited classes of drugs that are approved for the treatment of such infections like polyenes, azoles, and echinocandins. Some fungi have developed resistance to these drugs. Therefore, to counter drug resistance, intensive large scale studies on novel targeting strategies and formulations are being conducted, which have gained impetus lately. Conventional formulations have limitations such as higher doses, frequent dosing, and several side effects. Such limiting factors have paved the path for the emergence of nanotechnology and its applications. This further gave formulation scientists the possibility of encapsulating the existing potential drug moieties into nanocarriers, which when loaded into gels or creams provided prolonged release and improved permeation, thus giving on-target effect. This review thus discusses the newer targeting strategies and the role of nanocarriers that could be administered topically for the treatment of various fungal infections. Furthermore, this approach opens newer avenues for continued and sustained research in pharmaceuticals with much more effective outcomes.
    Matched MeSH terms: Azoles
  2. Walvekar S, Anwar A, Anwar A, Sridewi N, Khalid M, Yow YY, et al.
    Acta Trop, 2020 Nov;211:105618.
    PMID: 32628912 DOI: 10.1016/j.actatropica.2020.105618
    Acanthamoeba spp. are free living amoeba (FLA) which are widely distributed in nature. They are opportunistic parasites and can cause severe infections to the eye, skin and central nervous system. The advances in drug discovery and modifications in the chemotherapeutic agents have shown little improvement in morbidity and mortality rates associated with Acanthamoeba infections. The mechanism-based process of drug discovery depends on the molecular drug targets present in the signaling pathways in the genome. Synthetic libraries provide a platform for broad spectrum of activities due to their desired structural modifications. Azoles, originally a class of synthetic anti-fungal drugs, disrupt the fungal cell membrane by inhibiting the biosynthesis of ergosterol through the inhibition of cytochrome P450 dependent 14α-lanosterol, a key step of the sterol pathway. Acanthamoeba and fungi share the presence of similar sterol intermediate, as ergosterol is also the major end-product in the sterol biosynthesis in Acanthamoeba. Sterols present in the eukaryotic cell membrane are one of the most essential lipids and exhibit important structural and signaling functions. Therefore, in this review we highlight the importance of specific targeting of ergosterol present in Acanthamoebic membrane by azole compounds for amoebicidal activity. Previously, azoles have also been repurposed to report antimicrobial, antiparasitic and antibacterial properties. Moreover, by loading the azoles into nanoparticles through advanced techniques in nanotechnology, such as physical encapsulation, adsorption, or chemical conjugation, the pharmacokinetics and therapeutic index of the drugs can be significantly improved. The current review proposes an important strategy to target Acanthamoeba using synthetic libraries of azoles and their conjugated nanoparticles for the first time.
    Matched MeSH terms: Azoles/pharmacology*
  3. Vassiliev P, Iezhitsa I, Agarwal R, Marcus AJ, Spasov A, Zhukovskaya O, et al.
    Data Brief, 2018 Jun;18:340-347.
    PMID: 29896521 DOI: 10.1016/j.dib.2018.02.067
    This article contains data that relate to the study carried out in the work of Marcus et al. (2018) [1]. Data represent an information about pharmacophore analysis of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole derivatives and results of construction of the relationship between intraocular pressure (IOP) lowering activity and hypotensive activity of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole derivatives using a multilayer perceptron artificial neural network. In particular, they include the ones listed in this article: 1) table of all pharmacophores of imidazo[1,2-a]benzimidazole and pyrimido[1,2-a]benzimidazole derivatives that showed IOP lowering activity; 2) table of all pharmacophores of the compounds that showed absence of IOP lowering activity; 3) table of initial data for artificial neural network analysis of relationship between IOP activity and hypotensive activity of this chemical series; 4) graphical representation of the best neural network model of this dependence; 5) original txt-file of results of pharmacophore analysis; 6) xls-file of initial data for neural network modeling; 7) original stw-file of results of neural network modeling; 8) original xml-file of the best neural network model of dependence between IOP lowering activity and hypotensive activity of these azole derivatives. The data may be useful for researchers interested in designing new drug substances and will contribute to understanding of the mechanisms of IOP lowering activity.
    Matched MeSH terms: Azoles; Benzimidazoles
  4. Navarathinam SD, Neoh HM, Tan TL, Wahab AA, Mohd Nizam Tzar MN, Ding CH
    Malays J Pathol, 2023 Dec;45(3):417-424.
    PMID: 38155383
    BACKGROUND: Candida tropicalis is a globally distributed yeast that has been popping up in the medical literature lately, albeit for unenviable reasons. C. tropicalis is associated with substantial morbidity, mortality as well as drug resistance. The aims of this study were to ascertain the antifungal susceptibility profile and the biofilm-producing capability of this notorious yeast in our centre.

    METHODS: C. tropicalis isolates from sterile specimens were collected over a 12-month period. Conclusive identification was achieved biochemically with the ID 32 C kit. Susceptibility to nine antifungal agents was carried out using the colourimetric broth microdilution kit Sensititre YeastOne YO10. Biofilm-producing capability was evaluated by quantifying biomass formation spectrophotometrically following staining with crystal violet.

    RESULTS: Twenty-four non-repetitive isolates of C. tropicalis were collected. The resistance rates to the triazole agents were 29.2% for fluconazole, 16.7% for itraconazole, 20.8% for voriconazole and 8.3% for posaconazole-the pan-azole resistance rate was identical to that of posaconazole. No resistance was recorded for amphotericin B, flucysosine or any of the echinocandins tested. A total of 16/24 (66.7%) isolates were categorized as high biomass producers and 8/24 (33.3%) were moderate biomass producers. None of our isolates were low biomass producers.

    CONCLUSION: The C. tropicalis isolates from our centre were resistant only to triazole agents, with the highest resistance rate being recorded for fluconazole and the lowest for posaconazole. While this is not by itself alarming, the fact that our isolates were prolific biofilm producers means that even azole-susceptible isolates can be paradoxically refractory to antifungal therapy.

    Matched MeSH terms: Azoles; Triazoles
  5. Mohd Tap R, Kamarudin NA, Ginsapu SJ, Ahmed Bakri AR, Ahmad N, Amran F, et al.
    Genome Announc, 2018 Apr 05;6(14).
    PMID: 29622608 DOI: 10.1128/genomeA.00166-18
    Candida pseudohaemulonii is phylogenetically close to the C. haemulonii complex and exhibits resistance to amphotericin B and azole agents. We report here the draft genome sequence of C. pseudohaemulonii UZ153_17 isolated from the blood culture of a neutropenic patient. The draft genome is 3,532,003,666 bp in length, with 579,838 reads, 130 contigs, and a G+C content of 47.15%.
    Matched MeSH terms: Azoles
  6. Khodavandi A, Alizadeh F, Aala F, Sekawi Z, Chong PP
    Mycopathologia, 2010 Apr;169(4):287-95.
    PMID: 19924565 DOI: 10.1007/s11046-009-9251-3
    Candidiasis is a term describing infections by yeasts from the genus Candida, and the type of infection encompassed by candidiasis ranges from superficial to systemic. Treatment of such infections often requires antifungals such as the azoles, but increased use of these drugs has led to selection of yeasts with increased resistance to these drugs. In this study, we used allicin, an allyl sulfur derivative of garlic, to demonstrate both its intrinsic antifungal activity and its synergy with the azoles, in the treatment of these yeasts in vitro. In this study, the MIC(50) and MIC(90) of allicin alone against six Candida spp. ranged from 0.05 to 25 microg/ml. However, when allicin was used in combination with fluconazole or ketoconazole, the MICs were decreased in some isolates. Our results demonstrated the existing synergistic effect between allicin and azoles in some of the Candida spp. such as C. albicans, C. glabrata and C. tropicalis, but synergy was not demonstrated in the majority of Candida spp. tested. Nonetheless, In vivo testing needs to be performed to support these findings.
    Matched MeSH terms: Azoles/pharmacology*
  7. Mohd-Assaad N, McDonald BA, Croll D
    Mol Ecol, 2016 Dec;25(24):6124-6142.
    PMID: 27859799 DOI: 10.1111/mec.13916
    Evolution of fungicide resistance is a major threat to food production in agricultural ecosystems. Fungal pathogens rapidly evolved resistance to all classes of fungicides applied to the field. Resistance to the commonly used azole fungicides is thought to be driven mainly by mutations in a gene (CYP51) encoding a protein of the ergosterol biosynthesis pathway. However, some fungi gained azole resistance independently of CYP51 mutations and the mechanisms leading to CYP51-independent resistance are poorly understood. We used whole-genome sequencing and genome-wide association studies (GWAS) to perform an unbiased screen of azole resistance loci in Rhynchosporium commune, the causal agent of the barley scald disease. We assayed cyproconazole resistance in 120 isolates collected from nine populations worldwide. We found that mutations in highly conserved genes encoding the vacuolar cation channel YVC1, a transcription activator, and a saccharopine dehydrogenase made significant contributions to fungicide resistance. These three genes were not previously known to confer resistance in plant pathogens. However, YVC1 is involved in a conserved stress response pathway known to respond to azoles in human pathogenic fungi. We also performed GWAS to identify genetic polymorphism linked to fungal growth rates. We found that loci conferring increased fungicide resistance were negatively impacting growth rates, suggesting that fungicide resistance evolution imposed costs. Analyses of population structure showed that resistance mutations were likely introduced into local populations through gene flow. Multilocus resistance evolution to fungicides shows how pathogen populations can evolve a complex genetic architecture for an important phenotypic trait within a short time span.
    Matched MeSH terms: Azoles*
  8. Suresh Kumar
    Introduction: Tuberculosis (TB) is one of the utmost serious infectious diseases worldwide. The emergence of multi- drug resistance demands the development of better or new putative drug targets for tuberculosis. Recent studies sug- gest Mycobacterium tuberculosis cytochrome P450 enzymes as promising drug targets and azole drugs as potential inhibitors. Methods: Various computational tools, like Expasy Protparam, Swiss model, RaptorX and Phyre2 were used to analyze 12 Mycobacterium tuberculosis P450 enzymes and determine their three-dimensional structure. The structural validation was done through a Ramachandran plot using RAMPAGE server. The docking of P450 enzymes with azole drugs was done with autodock ver 4.2.6. Results: Based on sub-cellular localization prediction using CEL- LO tool, P450 enzymes CYP123A1, CYP132A1, CYP135A1, CYP136A1, CYP140A1, and CYP143A1 were predicted to be in the cytoplasm. Through structure assessment by Ramachandran plot, the best homology modelled proteins were docked with azole drugs like clotrimazole, croconazole, econazole, fluconazole, itraconazole, itraconazole, ketaconazole and micronazole by using autodock. By docking method it is identified that ketaconazole drug has a high affinity towards most of the mycobacterium P450 enzymes followed by the itrconazole drug. CYP123A1 enzyme is preferable as a drug target due to high binding affinity towards ketoconazole followed by CYP135A1, CYP140A1 enzymes. Conclusion: This study would help in identifying putative novel drug targets in Mycobacterium tuberculosis, which can lead to promising candidates for the optimization and development of novel anti-mycobac- terial agents.
    Matched MeSH terms: Azoles; Imidazoles
  9. James JE, Lamping E, Santhanam J, Milne TJ, Abd Razak MF, Zakaria L, et al.
    Front Microbiol, 2020;11:272.
    PMID: 32296397 DOI: 10.3389/fmicb.2020.00272
    In the fungal pathogen Aspergillus fumigatus, resistance to azole antifungals is often linked to mutations in CYP51A, a gene that encodes the azole antifungal drug target lanosterol 14α-demethylase. The aim of this study was to investigate whether similar changes could be associated with azole resistance in a Malaysian Fusarium solani species complex (FSSC) isolate collection. Most (11 of 15) clinical FSSC isolates were Neocosmospora keratoplastica and the majority (6 of 10) of environmental isolates were Neocosmospora suttoniana strains. All 25 FSSC isolates had high minimum inhibitory concentrations (MICs) for itraconazole and posaconazole, low MICs for amphotericin B, and various (1 to >32 mg/l) voriconazole susceptibilities. There was a tight association between a 23 bp CYP51A promoter deletion and high (>32 mg/l) voriconazole MICs; of 19 FSSC strains sequenced, nine isolates had voriconazole MICs > 32 mg/l, and they all contained the 23 bp CYP51A promoter deletion, although it was absent in the ten remaining isolates with low (≤12 mg/l) voriconazole MICs. Surprisingly, this association between voriconazole resistance and the 23 bp CYP51A promoter deletion held true across species boundaries. It was randomly distributed within and across species boundaries and both types of FSSC isolates were found among environmental and clinical isolates. Three randomly selected N. keratoplastica isolates with low (≤8 mg/l) voriconazole MICs had significantly lower (1.3-7.5 times) CYP51A mRNA expression levels than three randomly selected N. keratoplastica isolates with high (>32 mg/l) voriconazole MICs. CYP51A expression levels, however, were equally strongly induced (~6,500-fold) by voriconazole in two representative strains reaching levels, after 80 min of induction, that were comparable to those of CYP51B. Our results suggest that FSSC isolates with high voriconazole MICs have a 23 bp CYP51A promoter deletion that provides a potentially useful marker for voriconazole resistance in FSSC isolates. Early detection of possible voriconazole resistance is critical for choosing the correct treatment option for patients with invasive fusariosis.
    Matched MeSH terms: Azoles; Triazoles
  10. Anwar A, Mungroo MR, Khan S, Fatima I, Rafique R, Kanwal, et al.
    Antibiotics (Basel), 2020 Apr 17;9(4).
    PMID: 32316387 DOI: 10.3390/antibiotics9040188
    Balamuthia mandrillaris and Naegleriafowleri are opportunistic protozoan pathogens capable of producing infection of the central nervous system with more than 95% mortality rate. Previously, we have synthesized several compounds with antiamoebic properties; however, synthesis of compounds that are analogues of clinically used drugs is a highly desirable approach that can lead to effective drug development against these devastating infections. In this regard, compounds belonging to the azole class possess wide range of antimicrobial properties and used clinically. In this study, six novel benzimidazole, indazole, and tetrazole derivatives were synthesized and tested against brain-eating amoebae. These compounds were tested for their amoebicidal and static properties against N. fowleri and B. mandrillaris. Furthermore, the compounds were conjugated with silver nanoparticles and characterized. The synthetic heterocyclic compounds showed up to 72% and 65% amoebicidal activities against N. fowleri and B. mandrillaris respectively, while expressing up to 75% and 70% amoebistatic activities, respectively. Following conjugation with silver nanoparticles, amoebicidal activities of the drugs increased by up to 46 and 36% versus B. mandrillaris and N. fowleri. Minimal effects were observed when the compounds were evaluated against human cells using cytotoxicity assays. In summary, azole compounds exhibited potent activity against N. fowleri and B. mandrillaris. Moreover, conjugation of the azole compounds with silver nanoparticles further augmented the capabilities of the compounds against amoebae.
    Matched MeSH terms: Azoles; Benzimidazoles; Indazoles; Tetrazoles
  11. Kirubakaran R, Uster DW, Hennig S, Carland JE, Day RO, Wicha SG, et al.
    Br J Clin Pharmacol, 2023 Mar;89(3):1162-1175.
    PMID: 36239542 DOI: 10.1111/bcp.15566
    AIM: Existing tacrolimus population pharmacokinetic models are unsuitable for guiding tacrolimus dosing in heart transplant recipients. This study aimed to develop and evaluate a population pharmacokinetic model for tacrolimus in heart transplant recipients that considers the tacrolimus-azole antifungal interaction.

    METHODS: Data from heart transplant recipients (n = 87) administered the oral immediate-release formulation of tacrolimus (Prograf®) were collected. Routine drug monitoring data, principally trough concentrations, were used for model building (n = 1099). A published tacrolimus model was used to inform the estimation of Ka , V2 /F, Q/F and V3 /F. The effect of concomitant azole antifungal use on tacrolimus CL/F was quantified. Fat-free mass was implemented as a covariate on CL/F, V2 /F, V3 /F and Q/F on an allometry scale. Subsequently, stepwise covariate modelling was performed. Significant covariates influencing tacrolimus CL/F were included in the final model. Robustness of the final model was confirmed using prediction-corrected visual predictive check (pcVPC). The final model was externally evaluated for prediction of tacrolimus concentrations of the fourth dosing occasion (n = 87) from one to three prior dosing occasions.

    RESULTS: Concomitant azole antifungal therapy reduced tacrolimus CL/F by 80%. Haematocrit (∆OFV = -44, P 

    Matched MeSH terms: Azoles
  12. Siddiqui R, Aqeel Y, Khan NA
    Antimicrob Agents Chemother, 2016 11;60(11):6441-6450.
    PMID: 27600042 DOI: 10.1128/AAC.00686-16
    For the past several decades, there has been little improvement in the morbidity and mortality associated with Acanthamoeba keratitis and Acanthamoeba encephalitis, respectively. The discovery of a plethora of antiacanthamoebic compounds has not yielded effective marketed chemotherapeutics. The rate of development of novel antiacanthamoebic chemotherapies of translational value and the lack of interest of the pharmaceutical industry in developing such chemotherapies have been disappointing. On the other hand, the market for contact lenses/contact lens disinfectants is a multi-billion-dollar industry and has been successful and profitable. A better understanding of drugs, their targets, and mechanisms of action will facilitate the development of more-effective chemotherapies. Here, we review the progress toward phenotypic drug discovery, emphasizing the shortcomings of useable therapies.
    Matched MeSH terms: Azoles/pharmacology
  13. Iqbal K, Abdalla SAO, Anwar A, Iqbal KM, Shah MR, Anwar A, et al.
    Antibiotics (Basel), 2020 May 25;9(5).
    PMID: 32466210 DOI: 10.3390/antibiotics9050276
    The pathogenic free-living amoeba, Acanthamoeba castellanii, is responsible for a rare but deadly central nervous system infection, granulomatous amoebic encephalitis and a blinding eye disease called Acanthamoeba keratitis. Currently, a combination of biguanides, amidine, azoles and antibiotics are used to manage these infections; however, the host cell cytotoxicity of these drugs remains a challenge. Furthermore, Acanthamoeba species are capable of transforming to the cyst form to resist chemotherapy. Herein, we have developed a nano drug delivery system based on iron oxide nanoparticles conjugated with isoniazid, which were further loaded with amphotericin B (ISO-NPs-AMP) to cause potent antiamoebic effects against Acanthamoeba castellanii. The IC50 of isoniazid conjugated with magnetic nanoparticles and loaded with amphotericin B was found to be 45 μg/mL against Acanthamoeba castellanii trophozoites and 50 μg/mL against cysts. The results obtained in this study have promising implications in drug discovery as these nanomaterials exhibited high trophicidal and cysticidal effects, as well as limited cytotoxicity against rat and human cells.
    Matched MeSH terms: Azoles
  14. Wang H, Xu YC, Hsueh PR
    Future Microbiol, 2016 10;11:1461-1477.
    PMID: 27750452
    In the Asia-Pacific region, Candida albicans is the predominant Candida species causing invasive candidiasis/candidemia in Australia, Japan, Korea, Hong Kong, Malaysia, Singapore and Thailand whereas C. tropicalis is the most frequently encountered Candida species in Pakistan and India. Invasive isolates of C. albicans, C. parapsilosis complex and C. tropicalis remain highly susceptible to fluconazole (>90% susceptible). Fluconazole resistance (6.8-15%), isolates with the non-wild-type phenotype for itraconazole susceptibility (3.9-10%) and voriconazole (5-17.8%), and echinocandin resistance (2.1-2.2% in anidulafungin and 2.2% in micafungin) among invasive C. glabrata complex isolates are increasing in prevalence. Moreover, not all isolates of C. tropicalis have been shown to be susceptible to fluconazole (nonsusceptible rate, 5.7-11.6% in China) or voriconazole (nonsusceptible rate, 5.7-9.6% in China).
    Matched MeSH terms: Azoles/therapeutic use
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