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Clotrimazole as a pharmaceutical: Past, present and future
Abstract
Clotrimazole is a broad-spectrum anti-mycotic drug mainly used for the treatment of Candida albicans and other fungal infections. A synthetic, azole anti-mycotic, clotrimazole is widely used as a topical treatment for tinea pedis (athlete's foot), as well as vulvovaginal and oropharyngeal candidiasis. It displays fungistatic anti-mycotic activity by targeting the biosynthesis of ergosterol, thereby inhibiting fungal growth. As well as its anti-mycotic activity, clotrimazole has become a drug of interest against several other diseases such as sickle cell disease, malaria, and some cancers. It has also been combined with other molecules, such as the metals, to produce clotrimazole complexes that show improved pharmacological efficacy. Moreover, several new, modified-release pharmaceutical formulations are also undergoing development. Clotrimazole is a very well tolerated product with few side-effects, although there is some drug resistance appearing among immunocompromised patients. Here, we review the pharmaceutical chemistry, application and pharmacology of clotrimazole, and discuss future prospects for its further development as a chemotherapeutic agent.This article is protected by copyright. All rights reserved.
... It is a drug from the azole class of synthetic antifungals, discovered in 1960 by Karl Hienz Buchel. Azoles are the largest class of drugs that have antifungal properties [4][5][6][7]. The groups of these compounds can be divided based on their chemical structure into imidazoles and triazoles. ...
... It is mainly used to treat Candida albicans and other fungal infections. Due to its usefulness, it has been placed on the World Health Organization's list of essential medicines and is sold as a generic drug worldwide [4,5,8,9]. ...
... Although there are many antifungal agents on the pharmaceutical market with clotrimazole [2,4,6], these drugs cannot reach high concentrations at the site of infection due to rapid removal from the vagina, low volumes of vaginal mucus, and high anatomical variability. Therefore, the use of polymers with mucoadhesive properties that can interact with the mucous membrane is currently a very popular topic among researchers [1,10,11]. ...
The aim of this study was to prepare vaginal suppositories with mucoadhesive properties to prolong the action of antifungal component clotrimazole (CLO). This was achieved by preparing vaginal pessaries on a hydrophilic gel base composed of gelatin and gelatin enriched with PEG 400 (in a 1:1 ratio), and then checking the properties of the obtained vaginal drugs. The prepared globules, containing 100 mg of CLO, were characterized in terms of mass and swelling index, organoleptic analysis was also prepared. In addition, a texture analysis and a study of the dissolution of clotrimazole were performed. On the basis of the obtained results, it was concluded that the modification of the composition of the gelatin–glycerin base by the addition of macrogol had a positive effect on the mucoadhesive properties of the globules. In addition, due to the presence of PEG 400, the globules were stiffer. It was also observed that the presence of CLO reduces the value of the force needed for compression during the texture analysis study. Comparing the CLO release profiles of the prepared globules and commercially available clotrimazole tablets, the release profile for the globules was slower than for the tablets, which indicates the possibility of using mucoadhesive globules as a form of a drug that releases the medicinal substance more slowly at the site of administration.
... This approach or strategy became very popular in the year 2020 with the sudden emergence of COVID-19, in which antimalarial medications such as hydroxychloroquine and chloroquine were repositioned as COVID-19 therapies [11]. Interestingly, previous reports had revealed the anti-malarial properties of the extensively used antifungal agent, clotrimazole [6,[12][13][14], which efficiently and quickly inhibits the development of parasites in six distinct strains of Plasmodium falciparum in vitro [1,6] and also achieved complete suppression of parasite replication within a single intraerythrocytic cycle at 2 µM and higher [1,15]. ...
... This finding confirmed the impact of controlled release reported in the preceding section regarding in vitro release of clotrimazole-loaded chitosan-coated SLNs. It equally serves as a confirmation of the drug's antimalarial properties both in vitro and in vivo as were reported previously by researchers [1,6,[12][13][14][15], which was corroborated by the observed antimalarial activity of clotrimazole pure sample. Therefore, the in vivo pharmacodynamic study's outcome was able to demonstrate that clotrimazole-loaded chitosan-modified SLNs administered orally can be used as a repurposed nanomedicine for oral malaria therapy. ...
Clotrimazole (CMZ), an antimycotic drug, has been reported to be experimentally effective for Plasmodium falciparum malaria treatment. However, clotrimazole is limited by poor dissolution in aqueous medium and degradation in harsh gastrointestinal tract (GIT) environments. Chitosan-coated nanoplatforms protect drugs against GIT degradation and improve their dissolution and therapeutic effects. Thus, in this study, clotrimazole was formulated in solidified reversed micellar solution (SRMS)-based chitosan-coated solid lipid nanoparticles (CS-SLNs) with the aim of protecting it against GIT degradation, enhancing its dissolution, and improving its antimalarial efficacy. Free and drug-loaded neutral and chitosan-coated SLNs were prepared employing high-shear melt-emulsification and thereafter investigated in terms of particle characteristics, encapsulation efficiency, scanning electron microscopy (SEM), powder x-ray diffractometry (PXRD), Fourier transform infra-red (FI-IR) spectroscopy, release profiles in media [hydrochloric acid buffer (pH = 1.2) and phosphate buffer (pH = 6.8)] containing 0.5% Tween 80, stability, and cytotoxicity. Antimalarial, hematological and histopathological studies were carried out in mice. The developed clotrimazole-loaded chitosan-coated SRMS-based SLNs (CMZ-CS-SLNs) were stable and showed good colloidal properties (size 346.35 ± 3.40 nm, PDI 0.259 ± 0.06, and ζ-potential + 30.54 ± 1.76 mV) and good encapsulation efficiency (79.03%). The release of CMZ from the formulations was unaffected by pH, with CMZ-CS-SLNs showing controlled drug release. PXRD confirmed the molecularly dispersed CMZ in CMZ-CS-SLNs, FT-IR results indicated chemical structure integrity of CMZ and components compatibility, while SEM showed smooth and uniform particles with a layer of polymer coating in CMZ-CS-SLNs. Furthermore, there were minimal effects on hematological parameters and significantly (****P < 0.0001) greater reduction in parasitemia (~ 3x) for CMZ-CS-SLNs (19.80%) than oral CMZ suspension (6.1%). Moreover, CMZ-CS-SLN demonstrated minimal toxicity on Caco-2 cells and equally ameliorated the Plasmodium berghei-induced liver and kidney complications in the malariogenic mice. Thus, SRMS-based CS-SLN is a promising nano-platform for enhanced delivery and antimalarial activity of CMZ.
... Clotrimazole ( Figure 3) is a crystalline, odorless powder with a color ranging from white to pale yellow; it is slightly soluble in water and it dissolves well in ethanol [37,38]. Although it is lipophilic in nature, it has poor absorption when applied to the skin [39]. CLO is available mainly in the form of products for topical use, primarily in the form of creams, solutions and balms; however, after local administration, it has poor bioavailability (ranging from 0.5 to 10%), and the highest concentration remains in the epidermis, especially in the s.c. ...
... CLO is available mainly in the form of products for topical use, primarily in the form of creams, solutions and balms; however, after local administration, it has poor bioavailability (ranging from 0.5 to 10%), and the highest concentration remains in the epidermis, especially in the s.c. Due to systemic toxicity and its limited absorption, it is not available in oral form; this means that new carriers for CLO are increasingly being sought to increase drug delivery to the site of infection [39,40]. ...
Mycoses of the skin are infectious diseases caused by fungal microorganisms that are generally treated with topical agents. However, such therapy is often ineffective and has to be supported by oral use of active substances, which, in turn, can cause many side effects. A good alternative for the treatment of deep-skin mycoses seems to be microneedles (MNs). The aim of this research was to fabricate and evaluate the properties of innovative MNs coated with a hydrogel as potential carriers for clotrimazole (CLO) in the treatment of deep fungal skin infections. A 3D printing technique using a photo-curable resin was employed to produce MNs, which were coated with hydrogels using a dip-coating method. Hydrogels were prepared with carbopol EZ-3 Polymer (Lubrizol) in addition to glycerol and triisopropanolamine. Clotrimazole was introduced into the gel as the solution in ethanol or was suspended. In the first step of the investigation, a texture analysis of hydrogels was prepared with a texture analyzer, and the drug release studies were conducted with the use of automatic Franz diffusion cells. Next, the release profiles of CLO for coated MNs were checked. The last part of the investigation was the evaluation of the antifungal activity of the prepared systems, and the inhibition of the growth of Candida albicans was checked with the diffusion and suspended-plate methods. The texture profile analysis (TPA) for the tested hydrogels showed that the addition of ethanol significantly affects the following studied parameters: hardness, adhesiveness and gumminess, causing a decrease in their values. On the other hand, for the gels with suspended CLO, better spreadability was seen compared to gels with dissolved CLO. The presence of the active substance did not significantly affect the values of the tested parameters. In the dissolution study, the results showed that higher amounts of CLO were released for MNs coated with a hydrogel containing dissolved CLO. Also, microbiological tests proved its efficacy against fungal cultures. Qualitative tests carried out using the diffusion method showed that circular zones of inhibition of fungal growth on the plate were obtained, confirming the hypothesis of effectiveness. The suspension-plate technique confirmed the inhibitory effect of applied CLO on the growth of Candida albicans. From the analysis of the data, the MNs coated with CLO dissolved in hydrogel showed better antifungal activity. All received results seem to be helpful in developing further studies for MNs as carriers of antifungal substances.
... Clotrimazole is a broad-spectrum antimycotic or antifungal agent. Its antimycotic properties were discovered in the late 1960s [3]. Clotrimazole falls under the imidazole category of azole antifungals. ...
... It is available in various preparations, including creams, pessaries, and troche formulations. The minimal side effect profile of this drug and its uncomplicated metabolic profile have led it to gain widespread acceptance for the treatment of mycotic outbreaks, such as vaginal yeast infections [3]. ...
Clotrimazole, a commonly used antifungal agent, is employed in the treatment of otomycosis and other ear infections. However, its use can lead to adverse drug reactions (ADRs), occasionally manifesting as local irritation or allergic responses. This abstract presents a case study of a patient exhibiting an adverse reaction to clotrimazole ear drops, highlighting the clinical presentation, management, and resolution of the ADR. The patient, a 73-year-old male, presented with itching and erythema over the left pinna extending up to the middle of the sternum following clotrimazole ear drop application. Immediate cessation of the medication and symptomatic treatment led to rapid resolution of symptoms. This case emphasizes the importance of recognizing potential ADRs associated with clotrimazole ear drops and the necessity of prompt intervention to mitigate adverse effects, thereby ensuring optimal patient care.
... Fluconazole, an imidazole wide-spectrum antimycotic agent, inhibits biosynthesis of sterols and ergosterols to pursue its fungistatic effect [4,5]. The drug is commonly used for skin, oral, and vaginal candida infections, typically given topically or as oral or vaginal troches, and it has only limited systemic absorption [6,7]. ...
This work aimed to increase the solubility of the poorly water-soluble drug fluconazole (BCS class II) using PEG-6000. Solid dispersion was prepared using the solvent evaporation method using different ratios of fluconazole and polymer (PEG-6000). Hereafter, mucoadhesive oral films were prepared by the solvent casting method with different ratios of polymer (HPMC E-15). The prepared films were characterised using film thickness, surface pH, folding endurance, weight uniformity, swelling index, disintegration test, drug content, and in vitro release study. A solubility study evaluated the polymer's effect on fluconazole's aqueous solubility. The in vitro dissolution rate of fluconazole from solid dispersion (SD) was significantly higher compared to pure fluconazole. Results revealed that selected ingredients were compatible and quite capable of producing films with desired characteristics.
... A strategy to overcome this problem is to design host-guest supramolecular systems with hydrophobic cavities, such as polymeric nanocarriers based on cyclodextrins (Peng et al., 2017). Clo, a topical broad-spectrum antifungal agent, is a fungistatic agent that alters the permeability of the cell membrane, leading to the destruction of fungal cells (Crowley & Gallagher, 2014). This drug is highly lipophilic (logP 4.1) with low aqueous solubility (0.49 mg/L) and requires frequent applications to sustain therapeutic levels (Pedersen, 1993). ...
... Sertraline concentrations in dewatered and biologically digested sludge collected prior to the onset of the COVID-19 pandemic (170-913 ng/g) (Verlicchi and Zambello 2015; Golovko et al. 2021) were less than those observed in this study. Other dominant PPCPs included the following: triclosan (median = 1545 ng/g), a commonly used preservative and chemical microbial agent that was subjected to risk management activities in 2020 (Government of Canada 2020); diphenhydramine (median = 547 ng/g), an antihistamine that is available without a prescription (Wolfson et al. 2022); doxycycline (median = 690 ng/g), a broad-spectrum antibiotic of the tetracycline class (Saatchi et al. 2021); clotrimazole (median = 828 ng/g), an antifungal medication that is commonly available without a prescription (Crowley and Gallagher 2014); and amitriptyline (median = 359 ng/g), an antidepressant (Luo et al. 2020) that is also used off-label to treat chronic pain, anxiety, and insomnia (Urits et al. 2019;Bakker et al. 2023). These concentrations were within the range observed in biosolids previously (Lajeunesse et al. 2012;Guerra et al. 2014;Verlicchi and Zambello 2015;Tran et al. 2018;Martin and Hart 2023). ...
The concentrations of 135 pharmaceuticals and personal care products (PPCPs) were determined in raw influent, final effluent, and treated biosolids at Canadian wastewater treatment plants (WWTPs) to evaluate the fate of PPCPs through liquid and solids trains of typical treatment types used in Canada and to assess changes in PPCP concentrations in wastewater matrices between 2010–2013 and 2022. PPCPs dominant in influent and effluent included the antidiabetic metformin, analgesics/anti-inflammatories (acetaminophen, ibuprofen, 2-hydroxy-ibuprofen), caffeine and its metabolite (1,7 − dimethylxanthine), theophylline (a bronchodilator and metabolite of caffeine), an insect repellent (N,N-diethyl-m-toluamide, DEET), and iopamidol (a contrast media for X-rays). PPCPs dominant in biosolids differed from those in influent/effluent and included antibiotics (fluoroquinolones and doxycycline), antidepressants (sertraline, citalopram, and amitriptyline), a preservative and antimicrobial agent (triclosan), an antihistamine (diphenhydramine), and an antifungal (clotrimazole). These elevated concentrations in influent/effluent and biosolids reflected their use in Canadian communities. PPCPs dominant in influent/effluent had relatively low hydrophobicity whereas those in biosolids tended to be more hydrophobic, or electrostatic forces governed their sorption. Higher removal of PPCPs was generally observed at WWTPs that used biological treatment compared to primary physical/chemical treatment. PPCP concentration changes in wastewater matrices between 2010–2013 and 2022 were influenced by risk management measures, warnings, the development of new pharmaceuticals, the COVID-19 pandemic, and other factors. These time trends reflected the limited information available on PPCP use in Canada. Continued periodic monitoring of PPCPs is recommended to fill data gaps on community use and release to the environment.
... The sensitivity to Calcofluor white and Congo red of the mutant ΔplcH was slightly increased at 50°C ( Figure 4B), indicating that deletion of the plcH gene interferes with cell wall biosynthesis at a higher temperature and that the increase in α-glucans can compensate for the cell wall defect at 37°C ( Figure 4A). Itraconazole and Clotrimazole are azole drugs that block the biosynthesis of ergosterol by targeting cytochrome P450-dependent enzymes [35][36][37][38] . Terbinafine can inhibit squalene epoxidase and interfere with the biosynthesis of ergosterol 39,40 . ...
Glycosylphosphatidylinositol (GPI) anchoring is one of the conserved posttranslational modifications in eukaryotes that attach proteins to the plasma membrane. In fungi, in addition to plasma membrane GPI‐anchored proteins (GPI‐APs), some GPI‐APs are specifically released from the cell membrane, secreted into the cell wall, and covalently linked to cell wall glucans as GPI‐anchored cell wall proteins (GPI‐CWPs). However, it remains unclear how fungal cells specifically release GPI‐CWPs from their membranes. In this study, phospholipase PlcH was identified and confirmed as a phospholipase C that hydrolyzes phosphate ester bonds to release GPI‐APs from the membrane of the opportunistic fungal pathogen Aspergillus fumigatus. Deletion of the plcH gene led to abnormal conidiation, polar abnormality, and increased sensitivity to antifungal drugs. In an immunocompromised mouse model, the ΔplcH mutant showed an attenuated inflammatory response and increased macrophage killing compared with the wild type. Biochemical and proteomic analyses revealed that PlcH was involved in the localization of various cell wall GPI‐APs and contributed to the cell wall integrity. Our results demonstrate that PlcH can specifically recognize and release GPI‐CWPs from the cell membrane, which represents a newly discovered secretory pathway of GPI‐CWPs in A. fumigatus.
... The GC-MS profiles of these metabolites displayed prominent ions at [M-CH 3 ] + and [M-TMSiOH-CH 3 ] + (Fig. 4B, C; Supplementary Fig. S6A, B), which are indicative of Δ 8 sterols with a 14α-methyl group (Goad and Akihisha, 1997). The accumulation of Δ 8 sterols with a 14α-methyl group is consistent with clotrimazole, bifonazole, and econazole inhibiting 14α-demethylase activity in Arabidopsis (AtCYP51G1), a deeply conserved target of many azoles (Lamb et al., 2001; Crowley and Gallagher, 2014). An NIST'20 database search revealed that the GC-MS spectrum of metabolite 4 matched with that of TMS-obtusifoliol (Fig. 4B), the preferred target of AtCYP51G1. ...
Sterols are produced via complex, multistep biosynthetic pathways involving similar enzymatic conversions in plants, animals and fungi, yielding a variety of sterol metabolites with slightly different chemical properties to exert diverse and specific functions. A tremendously diverse landscape of sterols, and sterol-derived compounds, can be found across the plant kingdom, determining a wide spectrum of functions. Resolving the underlying biosynthetic pathways is thus instrumental to understanding the function and use of these molecules. In only a few plants, sterol biosynthesis has been studied using mutants. In non-model species a pharmacological approach is required. However, this relies on only a few inhibitors. Here, we probed a collection of inhibitors of mammalian cholesterol biosynthesis to identify new inhibitors of plant sterol biosynthesis. We show that imidazole-type fungicides, bifonazole, clotrimazole and econazole inhibit the obtusifoliol 14α-demethylase CYP51 in plants. Moreover, we found that the selective estrogen receptor modulator, clomiphene, inhibits sterol biosynthesis in part by inhibiting the plant-specific cyclopropyl-cycloisomerase CPI1. These results demonstrate that rescreening of inhibitors animal sterol biosynthesis is an easy approach for identifying novel inhibitors of plant sterol biosynthesis. These molecules expand the toolkit for studying and manipulating sterol biosynthesis in the plant kingdom.
... Clotrimazole is well tolerated by patients and has insignificant complications. However, drug resistance is quite common in immunocompromised patients [10]. Also, a recent investigation elaborated on some adverse effects of clotrimazole such as burning sensation and occasional skin irritation [11]. ...
Objectives: This study aimed to compare the antifungal efficacy of Ganoderma lucidum (G. lucidum) and clotrimazole for treatment of denture stomatitis (DS). Materials and Methods: This double-blind randomized clinical trial was conducted on 50 patients with DS types I and II assigned to two groups (N=25). In the first group, G. lucidum extract was administered in the form of 5% gel while 1% clotrimazole gel was prescribed for the second group. Pain intensity according to the visual analog scale (VAS), and the percentage of DS recovery based on the Budtz-Jorgenson index were evaluated and recorded after 7 and 14 days. Data were analyzed using the Chi-square test, independent samples t-test, repeated measures ANOVA, and logistic regression (alpha=0.05). Results: The percentage of complete recovery on day 7 in the G. lucidum group (28%) was higher than that in the clotrimazole group (16%) but not significantly (P=0.592). Not wearing dentures overnight significantly increased the odds of recovery by 6.56 times, while the odds of recovery decreased by 0.03 times in DS type II, as compared to DS type I (P= 0.009). Conclusion: No significant difference existed between the antifungal efficacy of G. lucidum and clotrimazole for clinical treatment of DS. Thus, Ganoderma may be regarded as an alternative treatment, especially in patients’ resistant to azoles. Nonetheless, further clinical studies are required to shed more light on this topic.
... It has a poor aqueous solubility of 0.49 mg/L at 25 °C, which leads to poor and erratic bioavailability, with a maximum concentration (C max ) attained after 6 hours when administered orally. Soluble in polyethylene glycol 400, ethanol, and methanol [5,6]. Despite effective antifungal therapy, CLM has extensive hepatic inactivation and causes gastric disturbance, in addition to its poor solubility, which restricts its use for topical application [7]. ...
The study aimed to formulate Clotrimazole (CLM) as solid dispersion medicated lozenges with enhanced dissolution for treating oropharyngeal candidiasis. They are suitable for many patients and easy to administer. The study used the solvent evaporation method to prepare solid dispersions of CLM using polyethylene glycol 6000 and polyvinyl pyrrolidone at different drug-to-carrier weight ratios. The study found that PEG 6000, when used at a 1:1 weight ratio, significantly improved the dissolution of CLM. The results of the FTIR studies showed that the drug was dispersed within PEG 6000, and there was no drug interaction with the excipients used in medicated lozenge formulations. A 32-factorial design was used to develop, optimize, and evaluate nine formulations of the solid dispersion of CLM/PEG 6000 medicated lozenges for improved therapeutic outcomes. We fabricated the lozenges using biocompatible polymeric gelling agents (chitosan, methyl cellulose, and sodium alginate) at three different levels (0.5, 1, and 1.5%). All the medicated lozenges were uniform in weight and drug content within USP limits, with complete drug release rates ranging from 10–20 minutes for chitosan and sodium alginate formulations, compared to 60 minutes for methyl cellulose. The results showed that the type of polymer and its concentration significantly impacted drug release. The optimized formulation, F-3, containing 1.5% CH, exhibited a drug release of 100.83% ±0.68 at the end of 10 minutes. It demonstrated significant antifungal activity against Candida albicans (p < 0.05), making it suitable for drug delivery in the oral cavity.
... Drug repurposing in cancer is more cost-effective than developing new drugs 31 . CTZ is a synthetic azole antifungal drug commonly used topically to treat tinea pedis, vulvovaginal, and oropharyngeal candidiasis 8 . It inhibits fungal growth by targeting ergosterol biosynthesis and is safe and welltolerated with few adverse effects. ...
Patients with multiple myeloma (MM) experience relapse and drug resistance; therefore, novel treatments are essential. Clotrimazole (CTZ) is a wide-spectrum antifungal drug with antitumor activity. However, CTZ’s effects on MM are unclear. We investigated CTZ’s effect on MM cell proliferation and apoptosis induction mechanisms. CTZ’s effects on MM.1S, NCI- H929, KMS-11, and U266 cell growth were investigated using Cell Counting Kit-8 (CCK-8) assay. The apoptotic cell percentage was quantified with annexin V-fluorescein isothiocyanate/7-amino actinomycin D staining. Mitochondrial membrane potential (MMP) and cell cycle progression were evaluated. Reactive oxygen species (ROS) levels were measured via fluorescence microscopy. Expression of apoptosis-related and nuclear factor (NF)-κB signaling proteins was analyzed using western blotting. The CCK-8 assay indicated that CTZ inhibited cell proliferation based on both dose and exposure time. Flow cytometry revealed that CTZ decreased apoptosis and MMP and induced G0/G1 arrest. Immunofluorescence demonstrated that CTZ dose-dependently elevated in both total and mitochondrial ROS production. Western blotting showed that CTZ enhanced Bax and cleaved poly ADP-ribose polymerase and caspase-3 while decreasing Bcl-2, p-p65, and p-IκBα. Therefore, CTZ inhibits MM cell proliferation by promoting ROS-mediated mitochondrial apoptosis, inducing G0/G1 arrest, inhibiting the NF-κB pathway, and has the potential for treating MM.
... These infections are mor e fr equent in elderly w omen and uncir cumcised males and they usually manifest early in the course of empagliflo zin. Ho w ev er, empagliflozin is generally not r equir ed to be discontinued in such infections as they are r eadily cur ed with topical antifungal cr eams or oral antifungal medications [ 66 ]. Additionally, special counseling on maintaining the hygiene of the perineal area should be given to pa tien ts. ...
Abstract:
Heart failure (HF) affects more than 60 million individuals globally. Empagliflozin is currently approved for type 2 diabetes and chronic HF. Clinical trials have demonstrated that empagliflozin reduces the composite end point of hospitalizations for HF and mortality and improves the quality of life irrespective of left ventricular ejection fraction. Empagliflozin is a once-daily medication with minimal drug–drug interactions and does not require titration. Empagliflozin causes mild weight loss and does not significantly reduce blood pressure. Empagliflozin acts as an enabler for other HF drugs by reducing the risk of hyperkalemia. Empagliflozin is also beneficial for chronic kidney disease which exists commonly with HF. This review outlines the pharmacokinetics, pharmacodynamics, safety, and efficacy of empagliflozin in HF across various sub-groups and settings.
... Blocking of IKca channels by clotrimazole, interestingly, decreased the vascular response to the peptide uncovering some underlying mechanisms that interferred with its blocking properties. However, because clotrimazole selectively inhibits cytochrome-P450 (Crowley and Gallagher, 2014) it is reasonable to interfere with the biosynthesis of the vasoactive agents produced by the endothelial or VSMCs. Also, clotrimazole inhibits COX pathways and TXA2 synthesis in various cellular systems through suppressing the cytochrome-p450-dependent pathways of arachidonic acid metabolism (Tep-Areenan and Sawasdee, 2010). ...
Urotensin-II (U-II), the most potent vasoconstrictor that has recently been recognized as a new candidate in cardiovascular dysfunction, might exert vasoconstriction through, at least partially, potassium channels that are predominant in both endothelial and vascular smooth muscle cells (VSMCs). The present study was designed to evaluate the roles of potassium channels in vascular responses to U-II in intact and mercury induced endothelial dysfunction in rat aorta. The study involved pre-incubation of rat aortic rings with potassium channels blockers: charybdotoxin (chtx), tetraethylammonium (TEA), barium chloride (BaCl2), glibenclamide, 4-aminopyridine (4-AP) and clotrimazole. Then vascular responses to increased concentrations of human U-II (hU-II) were applied to each group in the presence and absence of mercury chloride (HgCl2). Urotensin-II efficacy was significantly increased in chtx, TEA and BaCl2 treated groups, while significantly decreased in glibenclamide and clotrimazole treated groups as compared with the control group. In the presence of mercury, hU-II efficacy was significantly changed in all groups except clotrimazole treated group. The novel findings were that potassium channels modulated the vascular contractile responses to hU-II in isolated rat aorta and mercury treatment increased hU-II efficacy and deteriorated potassium signaling.
... Clotrimazole is BCS class Ⅱ drug with strong antifungal effects and is available in several different formulations, including creams, tablets and gels. Its solubility and release profile can be improved by forming complex with beta-cyclodextrin (18). It is used to treat trichomoniasis that is resistant to metronidazole. ...
This research was framed to formulate clotrimazole-loaded beta cyclodextrin-based nanosponges that seemed to be effective for treating fungal infections. Beta-cyclodextrin (rate-retarding polymer), polyvinyl alcohol (surfactant) and dimethylsulfoxide (aprotic solvent) were utilized in different concentrations, to prepare clotrimazole loaded nanosponges through emulsion solvent diffusion technology. Drug loaded nanosponges were evaluated for their physico-chemical parameters. Fourier Transform Infrared spectroscopy and scanning electron microscopy were used for structural analysis. Spherical, spongy, porous and nanosized three-dimensional structures of prepared nanosponges were obtained by SEM. Each formulation's particle size was in nanoscale range. The percentage yield ranged from 77% to 87%. The entrapment efficiency and drug loading were in the range of 80-90% and 83-85%, respectively, for each formulation. The development of inclusion complexes with porous and spherical morphology was verified by FTIR without any chemical interaction between drug and polymer. These findings reinforced that developed nanosponge formulation serves as an effective nanocarrier, enhancing and regulating the delivery of clotrimazole.
... 2019) investigated the effect of vaginal cream of honey (30%) and cinnamon (3%) on VVC improvement. Honey and cinnamon vaginal cream was meaningfully irritating less than clotrimazole, but the culture results were similar in the two groups [22]. ...
Honey has been used since ancient times to treat various diseases such as gynecological diseases. The current study aims to investigate clinical trials related to the therapeutic effects of honey on women's diseases. Databases including Web of Science, Scopus, PubMed, Google scholar, and SID were investigated for clinical studies focusing on honey in gynecological diseases up to 31 June 2022. Eligibility was checked based on selection criteria. Twenty-five clinical trials met the inclusion criteria. Therapeutic properties of honey and its compounds as a systemic and/or local treatment on vulvovaginal candidiasis, cervicitis, dysmenorrhea, premenstrual syndrome, labor pain, episiotomy and cesarean wounds, nipple fissure, breast cancer and intrauterine insemination (IUI), with the mechanisms of action of antibacterial, antifungal, anti-inflammatory, wound healing, analgesic, antioxidant and anticancer activities have been proven. It was also found that phenolic compounds including flavonoids and phenolic acids are the main ones responsible for most of these therapeutic effects of honey. This study supports the healing properties of honey in gynecological diseases at reproductive age. Also, in the current studies, honey proved safe with minor adverse effects. Of course, to achieve definitive conclusions about the effectiveness and safety of honey, it is necessary to conduct more clinical trials with a larger sample size, appropriate intervention duration, and optimal doses in future studies.
... As clotrimazole has also been experimentally proven to inhibit cytochrome-P450 [27], an enzyme that converts arachidonic acid into powerful vasorelaxant products such epoxyeicosatrienoic acids [28]. With the use of this blocker, we were able to show for the first time that cytochrome P450-derived epoxyeicosatrienoic acids contribute to apelin-induced vasodilator tone in the rat aorta artery. ...
Diabetes is associated with endothelial dysfunction, which impairs blood vesselscapacity to maintain vascular tone. Apelin is an adipocyte-produced relaxing factor that has endothelium-dependent and nitric oxide (NO)-mediated vasorelaxant effects. The current study investigated how streptozotocin (STZ)-induced type one diabetes modulates the mechanisms involved in aortic vascular response to apelin, focusing on the role of potassium channels and endothelial derived relaxing factors (EDRF). In this study, precontracted rat thoracic aortic segments were pre-incubated with the NO inhibitor, cyclooxygenase (COX) inhibitor and potassium channels blockers including: non-selective calcium-activated potassium channel, big conductance calcium-activated potassium channels (BKca), intermediate conductance calcium activated potassium channels (IKca), delayed inward rectifier potassium channels (Kir), adenosine triphosphates-sensitive potassium channels (KATP) and voltage sensitive potassium channels (Kv) blockers, then cumulative concentrations of apelin were applied to each group in both non-diabetic and diabetic conditions. The statistical analysis between diabetic and non-diabetic groups revealed that endothelial impairment induced by diabetes in rat thoracic aorta remarkably attenuated the vascular responses to apelin. An important new finding in this study was that almost all potassium channels blockers noticeably P<0.001 increased apelin efficacy with relatively no changes in the peptide potency. However, in diabetic aortic segments, the non-selective Kca, BKca blockers, NO inhibitor and COX inhibitor reversed vascular responses to apelin, but Kir, KATP and Kv blockers significantly reduced vascular responses to apelin in comparison to control rats. It is worth noting that diabetes did not only alter the peptide potency in these experimental groups but also significantly increased the maximum responses when Kca and BKca blockers preincubated. In conclusion, our findings shed light on the mechanisms behind diabetes-induced aortic artery hypo-reactivity to apelin which involve the inhibition of endothelial NO synthase activities and decreased contribution of Kca, BKca, IKca, Kv, Kir and KATP channels.
... In keeping with the United States Pharmacopoeia safety of essential drugs, [17] CXB 2 % (w/w) was added in μE consisting of Tween-80 (67.5 %), Span-80 (7.5 %), olive oil (10 %) and water (15 %). CXB-free μE and CXB-loaded μE were stable and homogenous over 12 months. ...
Microemulsion‐based gels (μEGs) are smart colloidal carriers, superior to traditional topical formulations due to formulation simplicity, structural flexibility, high stability, and controlled delivery of topical drugs through biofilms. Here, we report a new μEG formulation for topical application of an anti‐inflammatory drug, celecoxib (CXB). For this, the μE system was formulated using olive oil (~10 %), Water (~15 %), Tween‐80 (~67.5 %) and Span‐80 (~7.5 %) to enhanced the loading of CXB (~2.0 wt.%), and then gelled to semisolid μEG by the addition of polyethylene glycol 6000 (PEG‐6000) (2.0 wt.%) to modulate CXB passage across the skin‐barriers. Optical microscopy showed the transition from water‐in‐oil (w/o) to oil‐in‐water (o/w) through bicontinuous networks. Dynamic light scattering and electron micrographs demonstrate very fine unimodal assembly of CXB‐μE nanodroplets (~65 nm), which didn't amalgamate to form spherical CXB‐μEG (~95 nm) after gelation. Moreover, FTIR analysis showed effective encapsulation of CXB into hydrophobic microenvironment with no observable chemical interaction between CXB and μE excipients, which was further verified by the peak‐to‐peak measurement of fluorescence. Further, ex‐vivo permeation of CXB‐μEG showed enhanced and persistent permeation (>99 %) within 10 hours at pH=5.5 into rabbit skin barrier. This demonstrates the sustained release of CXB in μEG and the enhancement in transdermal delivery over its conventional topical formulations.
... Moreover, we aimed to clarify if the biosensor developed was specific to TEB or if it was also capable of detecting other azole compounds, since most of these fungicides share the mode of action (Joseph-Horne et al. 1995;Lamb et al. 1999). For this purpose, we selected myclobutanil (MYC), another triazole fungicide used to control fungal diseases in crop production (Fonseca et al. 2019), as well as antifungal pharmaceutical azoles used to treat fungal infections, which share the mode of action but reach aquatic environments via wastewater (Berkow and Lockhart 2017;Crowley and Gallagher 2014), namely clotrimazole (CLO) and fluconazole (FLU). ...
Due to increasing demand for high and stable crop production, human populations are highly dependent on pesticide use for growing and storing food. Environmental monitoring of these agrochemicals is therefore of utmost importance, because of their collateral effects on ecosystem and human health. Even though most current-use analytical methods achieve low detection limits, they require procedures that are too complex and costly for routine monitoring. As such, there has been an increased interest in biosensors as alternative or complementary tools to streamline detection and quantification of environmental contaminants. In this work, we developed a biosensor for environmental monitoring of tebuconazole (TEB), a common agrochemical fungicide. For that purpose, we engineered S. cerevisiae cells with a reporter gene downstream of specific promoters that are expressed after exposure to TEB and characterized the sensitivity and specificity of this model system. After optimization, we found that this easy-to-use biosensor consistently detects TEB at concentrations above 5 μg L⁻¹ and does not respond to realistic environmental concentrations of other tested azoles, suggesting it is specific. We propose the use of this system as a complementary tool in environmental monitoring programs, namely, in high throughput scenarios requiring screening of numerous samples.
Key points
• A yeast-based biosensor was developed for environmental monitoring of tebuconazole.
•The biosensor offers a rapid and easy method for tebuconazole detection ≥ 5 μg L⁻¹.
•The biosensor is specific to tebuconazole at environmentally relevant concentrations.
... As a result, the intracellular elements of the fungus are reduced [7]. Clotrimazole is effective in treating more fungal infections, and is applied in the treatment of Tinea pedis, Tinea cruris, Tinea versicolor, Tinea corporis, skin candidiasis, vulvovaginal candidiasis and oropharyngeal candidiasis, as well as the prevention of oropharyngeal candidiasis in immunocompromised patients [8,9].Several formulations, such as topical cream/ointment/solution, oral tablet/lozenge, and vaginal cream/pessary have been produced for clotrimazole. Medicinal chewing gums can release their medication slowly in the saliva [10]. ...
Background: Oral candidiasis is widespread in the patients with immunodeficiency diseases. Chewing gums are considered as mobile drug delivery systems that affected locally or systemically via the oral cavity. This study aimed to develop and evaluate the formulation of clotrimazole chewing gums for patients having oral candidiasis. Materials and Methods: Fourteen formulations (F) were designed by Design-Expert, version 7. These formulations were different in the amount of gum bases and sweeteners. Gum bases of elvasti, 487, stick, and fruit C were heated up to 70°C. Clotrimazole powder, sugar, liquid glucose, glycerin, mannitol, xylitol, and maltitol as well as different flavoring agents were added to the gum bases at 40°C. Content and weight uniformity, organoleptic properties evaluation, releasing the active ingredient in the phosphate buffer pH, 6.8, and taste evaluation were analyzed by Latin square analysis. Also, the mechanical test was done on F13 and F14 formulations. Results: F14 was the best formulation in terms of organoleptic properties. This formulation had suitable size, hardness, softness, and lack of adhesion to teeth. F14 formulation released 89% and 97% of clotrimazole after 30 and 45 minutes, respectively. F14 content uniformity and weight variations were 9.83±0.086 mg and 1.14±0.09 g, respectively. F14 evaluation of mechanical properties showed Young’s modulus about 0.32 MPa, and yield point occurred at the stress of 0.599 MPa and strain of 4.1%. Conclusion: F14 was chosen according to its physicochemical and organoleptic properties. F14 had adequate hardness, lack of adhesion to the teeth, suitable size, and best drug release. Tutti Frutti was a proper flavoring agent for clotrimazole gum formulations.[GMJ.2021;10:e1084]
... The strains against which it is most effective are known to be Candida spp., Vulvovaginal candidiasis, Trichophyton spp., Microsporum spp., and Malassezia furfur. [23][24][25] It also has anticancer properties and has been researched for its potential in breast cancer cell lines (drug repositioning). It acts by inhibiting glycolytic enzymes (hexokinase, phosphofructokinase, and aldolase), which may lead to deprivation of cancer cells. ...
A reverse-phase high-performance liquid chromatographic (RP-HPLC) method was developed to analyze the simultaneous estimation of doxorubicin and clotrimazole. The method was achieved by Nucleodur C18 column with dimension 250 × 4.6 mm (5 μm) using gradient elution. The mobile phase contained 0.2% formic acid (pH 3.2) and acetonitrile. The flow rate was kept at 1.0 mL/min and detection and quantitation of both drugs (doxorubicin and clotrimazole) were achieved using a photodiode array detector at 276 nm, which was the isosbestic point for both drugs. The proposed method was validated according to the current International Council for Harmonization of Technical Requirements of Pharmaceuticals for Human Use guidelines for specificity, linearity, accuracy, precision, and robustness. The developed method showed a linear response (R2 > 0.999) and was accurate (recoveries 97%–103%), precise (resolution ≤1.0%), sensitive, and specific. Thus, the developed RP-HPLC method for the simultaneous estimation of both drugs was successfully validated and can be utilized for the estimation of these drugs in the formulations being developed.
... Another compound often used in topical formulations is clotrimazole, which is a nonbiodegradable chemical compound. The halflife of this compound is 60 days, being considered a chemically persistent chemical compound [9]. Regarding clotrimazole, its cytotoxicity can be increased by complexing with ruthenium, gold, or platinum [10]. ...
Two antimicrobial gels, formulated with natural biopolymers (collagen and chitosan), limonene, and an imidazole derivative, were subjected to cytotoxicity tests. In these two compositions, the limonene content was 0.4% and 0.67%. The cytotoxicity tests were performed in vitro, using MTT methodology, and a standardized human normal cells line, HUVEC type. These cells were exposed to different levels of gel concentrations in the culture media. The final concentration of each gel type in culture media was situated between (0-0.125) μL/mL. The cell viability was determined after 24, 48 and 72h of exposure. The analyses showed that after 24h of exposure, the viability of the cells is greater than 91%, after 48h the viability is greater than 80%; after 72 h of exposure, the viability of the cells is greater than 74%. These values reveal that both selected gels exhibit no cytotoxicity for the normal cell line.
... Treatment of vaginal yeast infections, dermatophytes, Candida infections, oral thrush, ringworm, athlete's foot, and jock itch, as well as a wide variety of other fungal infections in people and animals, is common use for the antifungal drug clotrimazole. An efficient antifungal agent in topical infections, it is generally recognised as safe [20][21][22][23] and is on the World Health Organization's (WHO) list of essential medications. Improving medication residence time and decreasing absorption into systemic circulation by controlling the release of a drug from the topical formulation to the epidermis/topical layer of the skin would lessen side effects. ...
The study's overarching goal is to develop a novel medication delivery method based on microsponge gel containing clotrimazole. Clotrimazole is poorly absorbed from the gastrointestinal tract (GIT), has a short half-life of only 2 h, & is metabolized into inert molecules by the liver. Therefore, clotrimazole's drug delivery method must be modified for topical application. Microsponge delivery is a novel approach to sustained drug release. Microsponges were made with a polymer solution of Eudragit RS 100 in dichloromethane (DCM) and ethanol (1:1) using a quasi-emulsion solvent diffusion technique. A number of metrics, including production yield, entrapment efficiency, particle size measurement, and in vitro drug release studies, were used to each microsponge formulation. For topical administration, the optimized microsponge formulation F6 was transformed into a gel formulation. Prepared gel was compared to a commercially available formulation based on physical factors such as pH, viscosity, spreadability, drug content, and an in vitro diffusion investigation. Most of the formulations were discrete and spherical in shape, indicating a satisfactory production yield, suggesting quasi-emulsion solvent diffusion method is a promising methodology for the fabrication of microsponge. Clotrimazole was released steadily over the course of 12 hours from the microsponge gel formulation MGI (F6). Therefore, the medicine in the form of a microsponge can reduce the risk of adverse effects and increase patient compliance by avoiding skin contact.
... Microsponge can provide sustained and controlled release of the entrapped drug. Microsponge system allows for a high accumulation of the drug in the skin, with relatively low permeation flux as compared to conventional dosage forms [17][18]. ...
The quasi emulsion solvent diffusion technique was used to create the clotrimazole microsponges, which were eventually recognized as an efficient carrier for the topical delivery of the medicine. The characteristics of the created system were significantly affected by the drug:polymer ratio. It was discovered that microsponges made for prolonged release formulation were effective, and clotrimazole microsponges with gel produced results that were equivalent. Microsponge gel compositions that were prepared beforehand showed regulated medication release. It has been shown that microsponges can transport medications for topical antifungal therapy successfully. Given how well the formulations kept the medication on the skin, it appears that microsponge gel is a more effective drug delivery mechanism than ordinary gel.
Fungal infections pose a significant global health problem, affecting 20–25% of the population and contributing to over 3.75 million deaths annually. Clotrimazole (CLO) is a widely used topical antifungal drug, but its efficacy is limited by poor penetration through the stratum corneum. Microneedle (MN) systems, composed of micron-scale structures arranged on a patch, offer a promising strategy to overcome the outermost skin barrier and enhance drug penetration into deeper layers. However, optimizing MN design, particularly in terms of size, shape, and fabrication technology, is essential for efficient drug delivery. This study aimed to develop CLO-coated MN systems using an Liquid Crystal Display (LCD)-based 3D printing technique and a thin-film dip-coating method. A comprehensive optimization of printing parameters, including anti-aliasing, layer thickness, curing time, and printing angle, was conducted to ensure the desired mechanical properties. The optimized MNs were coated with either suspension or ethanol-based CLO-hydrogels, with ethanol hydrogel demonstrating superior characteristics. Additionally, the study investigated how microneedle geometry and coating formulation influenced drug release. Antifungal activity against reference and clinical origin Candida albicans strains varied significantly depending on the coating formulation. Finally, the acute toxicity test confirmed no significant toxic effects on Aliivibrio fischeri, indicating the potential biocompatibility and safety of the developed MN-based drug delivery system.
In the past few decades, antibiotics have significantly improved patient health and enhanced the effectiveness of various treatments, including cancer therapy and organ transplants. However, the overuse of antibiotics has led to the emergence of drug-resistant bacteria, resulting in a decline in the effectiveness of antibiotics, creating an urgent need for alternative antibacterial agents. Antimicrobial peptides (AMPs) have emerged as a promising solution, with nearly 5000 natural AMPs identified from animals and plants. These peptides typically consist of 5–15 amino acids, exhibiting broad-spectrum antimicrobial activity and low toxicity, making them suitable candidates for therapeutic applications. This chapter primarily introduces the research and application progress of antimicrobial peptides from the aspects of their origin, classification and mechanism of action.
The objective of this study was to improve the solubility and dissolution profile of clotrimazole in the vaginal fluid for the treatment of fungal infection, a gamma-cyclodextrin-based clotrimazole nanogel was created for vaginal administration. The emulsion solvent evaporation process was used to prepare gamma-cyclodextrin-based nanogel. Aqueous phase was prepared using γCD, NaOH, EGDE and HPMC (1 %,2% w/w). Organic phase was prepared using Span 80(0, 0.5, 1, 2% w/v) in organic solvent dichloromethane. Aqueous phase was added to organic phase and homogenization was done followed by lyophilization. Formed solution was treated in an ultrasonic bath. The water was evaporated using a rotavapour. Schrodinger molecular docking software revealed a glide score of-2.85 kcal/mol for the gamma-cyclodextrin-clotrimazole complex, indicating the establishment of a hydrogen bond with a length of 2.4. The AL type of curve with a stability constant of 545 M-1 .was visible in the phase solubility diagram, indicating the production of 1:1 complexes. F8 was chosen as the optimal formulation batch. The mucoadhesion force (g) for batch F8 was 13.53g. When compared to pure Clotrimazole in the simulated vaginal fluid, the solubility of Clotrimazole in loaded nanogel increased by 15.45 fold. At the conclusion of six hours, there had been a 79.67% drug release with a drug flux of 1.3596 g/cm 2 /h. The Korsmeyer-Peppas model was used in the formulation of nanogel, with a r 2 value of 0.9984. The final formulation showed the highest zone of inhibition which is of standard zone of inhibition.
A Lewis acid-catalyzed regioselective C2’-electrophilic substitution of 2-indolylmethanols with pyrroles was established, which afforded indole-based tetraarylmethanes in overall high yields (up to 99%) with excellent regioselectivities. Moreover, such indole-based tetraarylmethanes exhibited potent cytotoxicity against HepG2 cancer cells, which demonstrated their potential applications in medicinal chemistry. This reaction not only represents the regioselective C2’-electrophilic substitution of 2-indolylmethanols with aryl nucleophiles (Ar-Nu), but also provides a new strategy for the synthesis of biologically important tetraarylmethanes.
Vaginal infections (VIs) are the result of the nefarious vaginal polymicrobial universe (i.e., Gardnerella vaginalis, Prevotella spp., Staphylococcus spp., Candida albicans, etc.), the inhabitants of which multiply and infect the surface of the vaginal epithelium, which serves as a scaffold for the adhesion of pathogenic poly-complexes with interactive abilities. VIs affect over 1 billion women per year and have a stunning annual relapse rate of 30%. These conditions impact women’s quality of life and fertility and cause oncogenic Human Papillomavirus (HPV) persistence. VIs are typically treated with oral (i.e., Flagyl®) and localized drug tablets and creams/gels (i.e., Clindesse®), with potential leakage from the vaginal tract upon administration leading to the failure of the treatment. This study intends to highlight polyphenols as potential therapeutic agents in terms of their benefits and limitations and suggest strategies to increase their effectiveness. Polyphenols are natural compounds rich in phenolic structures which have an impact on this type of pathology and deserve the utmost attention from researchers. Natural polyphenols have several advantages: renewability, biodegradability, low environmental impact, biocompatibility, application versatility, bioactive properties, and the potential for sustainable applications. These compounds, formulated in advanced delivery systems, may natively exhibit antioxidant, anti-inflammatory, and antimicrobial activities. The main objective of this review is to highlight the importance of researching new and effective formulations to prevent and treat VIs based on natural, controlled, and sustainable systems.
The present study involves the preparation of co-crystal forms of clotrimazole with co-formers namely nicotinic acid and naringenin. Clotrimazole is a BCS class II drug withlow solubility and high permeability. Hence by preparing the co-crystal, an attempt has been made to improve its solubility. Based on thehydrogen bond formation between the API and co-former, two co-formers were selected: nicotinic acid and naringenin. The co-crystals of clotrimazole with nicotinic acid and naringenin were prepared in the molar ratios of 1:1, 1:2, and 2:1 using dry grinding and solvent evaporation. PXRD, DSC and FTIR confirmed the formation of co-crystals. The solubility of co-crystals of clotrimazole with nicotinic acid was increased 2.07 folds for the ratios 1:2 prepared by solvent evaporation method compared to pure clotrimazole. The saturation solubility was also increased for the co-crystals of clotrimazole with naringenin by 2 folds for the ratio 2:1 prepared by solvent evaporation method compared to pure clotrimazole.
A series of new 4-(1,3,4-thiadiazol-2-yl)-containing polysubstituted pyrroles 3 a-k has been synthesized by a preparative convenient method from ethyl 5-chloro-4-formyl-1H-pyrrole-3-carboxylates 1 a-e, which were selectively transformed into the corresponding polysubstituted pyrrole-4-carboxylic acids 2 а-е using sodium hypochlorite as an oxidizer. Further, they were transformed into the target compounds with a high yield using the cyclocondensation with N-mono- or N,N-disubstituted thiosemicarbazides in the boiling phosphorus trichloroxide. As seen from the screening of antimicrobial activity, the synthesized compounds exhibit the inhibiting and bactericide activity against some bacteria and fungi. The highest activity has been established for the compounds 3 a, c, e-h, j against the strain Klebsiella pneumoniae (МІС=31.25 µg/mL). The calculated HOMO energy level proves that the compound 3 с is the most reactive ligand for the interaction with a protein receptor. The molecular docking data show that the compound 3 h has the highest affinity to the ThiM Klebsiella pneumoniae kinase.
Clotrimazole is a type of antifungal medication developed from azole compounds. It exhibits several biological actions linked to oxidative stress. This study focuses on the oxidative effects of clotrimazole on the eukaryotic model yeast, Saccharomyces cerevisiae. Our results showed that although initial nitric oxide levels were above control in clotrimazole exposed cells, they showed decreasing tendencies from the beginning of incubation and dropped below control at 125 µM from the 60th min. The highest superoxide anion and hydrogen peroxide levels were 1.95- and 2.85-folds of controls at 125 µM after 15 and 60 min, respectively. Hydroxyl radical levels slightly increased throughout the incubation period in all concentrations and reached 1.3-fold of control, similarly at 110 and 125 µM in the 90th min. The highest level of reactive oxygen species was observed at 110 µM, 2.31-fold of control. Although NADH/NADPH oxidase activities showed similar tendencies for all conditions, the highest activities were found as 3.07- and 2.27-folds of control at 125 and 110 µM in the 15th and 30th min, respectively. The highest superoxide dismutase and catalase activities were 1.59- and 1.21-folds of controls at 110 µM clotrimazole in 30 and 90 min, respectively. While the drug generally induced glutathione-related enzyme activities, the ratios of glutathione to oxidized glutathione were above the control only at low concentrations of the drug. The levels of lipid peroxidation in all treated cells were significantly higher than the controls. The findings crucially demonstrate that this medicine can generate serious oxidative stress in organisms.
Graphical Abstract
Since eukaryogenesis, chromatin has evolved to regulate gene expression. The histone variant H2A.Z is an ancestral, essential feature of eukaryotic chromatin linked to transcription. Curiously, it is a transcriptional activator in some species and a repressor in others, suggesting species-specific differences shape its function. Here we engineer H2A.Z sequence variants from diverse eukaryotes into a single host, Schizosaccharomyces pombe, to understand H2A.Z’s transcriptional impact. We show that H2A.Z sequences representing more than a billion years of evolution encode functional variation attributable to as little as single amino acid substitutions in the unstructured loop 2 (L2) region of H2A.Z’s core domain. We show that L2 binds elongation factor Spt6, with L2 sequence influencing its binding to Spt6 and whether it promotes or restricts transcription elongation. In this way, the H2A.Z-Spt6 interaction clarifies H2A.Z’s fundamental regulatory function, providing a direct physical and functional linkage between transcription and its chromatinized template across eukaryotes.
Human fungal pathogen Candida albicans causes oral infectious diseases such as oral thrush in immunocompromised patients with hyposalivation, diabetes mellitus, prolonged use of anti-biotics or immunosuppressive medicines and poor oral hygiene. An anti-fungal medication classified as a BCS class II drug, Clotrimazole has high permeability and low solubility in water. It is commercially available as lozenges, which do not uniformly distribute the drug within saliva for local therapy. This results in higher dose frequency and lower patient compliance. Therefore, in this study we proposed a niosomal based subgingival film formulation of clotrimazole for enhancing drug efficacy by improving drug solubilization capacity and improving patient compliance by prolonging the release of drug at the targeted site and reducing the dose frequency to show effective anti-fungal activity. The prepared niosomal film showed good entrapment efficiency and anti-fungal activity. Niosomal film showed better release pattern than drug loaded film.
Тіазольне ядро є ключовим елементом структури таких фармакологічно важливих типів сполук як антибіотики (Penicillin, Ceftriaxone, Ampicillin, Cefotaxime, Amoxicillin) та протимікробні препарати (Myxothiazole, Sulfathiazole, Ethaboxam, Abafungin, Ravuconazole). Поширеність тіазольного циклу в згаданих вище препаратах є вагомим підґрунтям для цілеспрямованого пошуку, скринінгу, розроблення та впровадження на його основі лікарських засобів із антимікробною дією. Саме тому, подане дослідження присвячене вивченню протибактеріальної та протигрибкової дії раніше синтезованих нових похідних 1,3-тіазолу, екзофункціоналізованих по положенню 4 арил- та гетарилтіозамісниками. Отримані результати проведеного біоскринінгу показали, що 4-тіометилфункціоналізовані 1,3-тіазоли характеризуються помірною бактерицидною та фунгіцидною активностями, які оцінювали за величинами зон пригнічення росту тест-культур, а також за величинами мінімальної бактеріостатичної концентрації (МБсК) та мінімальної фунгістатичної концентрації (МФсК) методом серійних розведень. З’ясоано, що найкращою антимікробною дією відзначається 3-(4-гідрокси-3-метоксифеніл)-2-(4-((5-нітро-1H-бензо[d]імідазол-2-ілтіо)метил) тіазол-2-іл)акрилонітрил 8 з МБсК 31.25 мкг/мл щодо бактерій Enterococcus faecalis ATCC 29212. При визначені мінімальної фунгістатичної концентрації методом серійних розведень встановлено, що сполуки 4, 7, 10, 13, 14, 16, 21 виявилися більш селективними щодо грибка Candida krusei ATCC 6258 з МФсК 15.625-31.25 мкг/мл.
Solid oral dosage forms are mostly preferred in pharmaceutical formulation development due to patient convenience, ease of product handling, high throughput, low manufacturing costs, with good physical and chemical stability. However, 70% of drug candidates have poor water solubility leading to compromised bioavailability. This phenomenon occurs because drug molecules are often absorbed after dissolving in gastrointestinal fluid. To address this limitation, delivery systems designed to improve the pharmacokinetics of drug molecules are needed to allow controlled release and target-specific delivery. Among various strategies, amorphous formulations show significantly high potential, particularly for molecules with solubility-limited dissolution rates. The ease of drug molecules to amorphized is known as their glass-forming ability (GFA). Specifically, drug molecules categorized into class III based on the Taylor classification have a low recrystallization tendency and high GFA after cooling, with substantial “glass stability” when heated. In the last decades, the application of mesoporous silica nanoparticles (MSNs) as drug delivery systems (DDS) has gained significant attention in various investigations and the pharmaceutical industry. This is attributed to the unique physicochemical properties of MSNs, including high loading capacity, recrystallization inhibition, excellent biocompatibility, and easy functionalization. Therefore, this study aimed to discuss the current state of good glass former drug loaded mesoporous silica and shows its impact on the pharmaceutical properties including dissolution and physical stability, along with in vivo study. The results show the importance of determining whether mesoporous structures are needed in amorphous formulations to improve the pharmaceutical properties of drug with a favorable GFA.
In vitro surrogate tests are broadly used for evaluation of the critical release characteristics of semi-solid dosage forms. In general, these tests are limited to assess the effect of crucial manufacturing process related steps on the physicochemical characteristics and overall drug product performance. In vitro release tests (IVRT) do not directly anticipate in vivo performance, but may detect in vitro changes that may correlate with in vivo performance. The objective of this work was to develop a suitable in vitro release test for evaluation of the similarity between two marketed Clotrimazole 1% Cream formulations. A systematic approach was used to address some essential qualification parameters and validation concepts described in EMA`s draft guideline on quality and equivalence of topical products. The procedure included suitable evaluation of the receptor medium, membrane qualification, followed by evaluation of method precision and method robustness. For evaluation of data, the comparison of Clotrimazole release profile met the relevant acceptance criteria for the 90% Confidence Interval for the ratio of means of the pairwise comparisons falling inside the limits of 90–111%. The linearity of the IVRT method as function of the drug concentration in the formulation was evaluated with 50% and 200% API formulations. In addition, the discriminatory power of the method was confirmed with formulation with altered viscosity as critical quality attribute. After validation of the method, the Clotrimazole 1% cream formulations were compared and their similarity was assessed. The approach was found to be useful and comprehensive in performing validation activities. Key words: IVRT, Clotrimazole cream formulation, method validation, discriminatory power
The prevalence of fungi infections has escalated in recent decades. Even though a large portion of fatalities caused by fungal infections are preventive, there is, however, an underappreciated subject for public health officials. Nanotechnology-based carriers have garnered considerable attention owing to their exceptional capabilities. The administration of antimycotic therapeutics with enhanced antifungal activity, bioavailability, localized action, and decreased cytotoxicity has been made possible by the use of nanoparticles (NPs) as effective drug delivery systems (DDS). This burgeoning field allows cross-disciplinary researchers to design and construct multifunctional NPs capable of targeting, diagnosing, and treating mycotic diseases. This research delves into an extensive exploration of various fungal infections and their therapeutic effectiveness through the utilization of a diverse range of cutting-edge nanocarrier-based technologies. These advanced technologies encompass transfersomes, ethosomes, transethosomes, niosomes, nanoemulsions, microemulsions, micelles, as well as distinct types of nanoparticles, including polymeric, inorganic, metal, solid lipid nanoparticles, dendrimers, and carbon nanotubes. The study examines the potential of these innovative delivery systems for combating fungal infections, shedding light on their efficacy and offering insights into their promising applications. By harnessing the distinctive properties and tailored characteristics of these nanocarriers, it becomes possible to optimize the delivery of antifungal agents, thus enhancing their therapeutic outcomes.
Ruthenium-based compounds have intriguing anti-cancer properties, and some of these novel compounds are currently in clinical trials. To continue the development of new metal-based drug combinations, we coupled ruthenium (Ru) with the azole compounds ketoconazole (KTZ) and clotrimazole (CTZ), which are well-known antifungal agents that also display anticancer properties. We report the activity of a series of 12 Ru-KTZ and Ru-CTZ compounds against three prostate tumor cell lines with different androgen sensitivity, as well as cervical cancer and lymphoblastic lymphoma cell lines. In addition, human cell lines were used to evaluate the toxicity against non-transformed cells and to establish selectivity indexes. Our results indicate that the combination of ruthenium and KTZ/CTZ in a single molecule results in complexes that are more cytotoxic than the individual components alone, displaying in some cases low micromolar CC50 values and high selectivity indexes. Additionally, all compounds are more cytotoxic against prostate cell lines with lower cytotoxicity against non-transformed epidermal cell lines. Some of the compounds were found to primarily induce cell death via apoptosis yet weakly interact with DNA. Our studies also demonstrate that the cytotoxicity induced by our Ru-based compounds is not directly related to their ability to interact with DNA.
The present work investigates the contribution of various second messenger systems to Ca2+-induced phosphatidylserine (PS) exposure in red blood cells (RBCs) from sickle cell disease (SCD) patients. The Ca2+ dependence of PS exposure was confirmed using the Ca2+ ionophore bromo-A23187 to clamp intracellular Ca2+ over 4 orders of magnitude in high or low potassium-containing (HK or LK) saline. The percentage of RBCs showing PS exposure was significantly increased in LK over HK saline. This effect was reduced by the Gardos channel inhibitors, clotrimazole and charybdotoxin. Nevertheless, although Ca2+ loading in the presence of an outwardly directed electrochemical gradient for K+ stimulated PS exposure, substantial exposure still occurred in HK saline. Under the conditions used inhibitors of other second messenger systems (ABT491, quinacrine, acetylsalicylic acid, 3,4-dichloroisocoumarin, GW4869 and zVAD-fmk) did not inhibit the relationship between [Ca2+] and PS exposure. Inhibitors of phospholipase A2, cyclooxygenase, platelet-activating factor, sphingomyelinase and caspases, therefore, were without effect on Ca2+-induced PS exposure in RBCs, incubated in either HK or LK saline.
The increasing resistance of the malaria parasite Plasmodium falciparum to currently available drugs demands a continuous effort to develop new antimalarial agents. In this quest, the identification of antimalarial effects of drugs already in use for other therapies represents an attractive approach with potentially rapid clinical application. We have found that the extensively used antimycotic drug clotrimazole (CLT) effectively and rapidly inhibited parasite growth in five different strains of P. falciparum, in vitro, irrespective of their chloroquine sensitivity. The concentrations for 50% inhibition (IC(50)), assessed by parasite incorporation of [(3)H]hypoxanthine, were between 0.2 and 1.1 microM. CLT concentrations of 2 microM and above caused a sharp decline in parasitemia, complete inhibition of parasite replication, and destruction of parasites and host cells within a single intraerythrocytic asexual cycle (approximately 48 hr). These concentrations are within the plasma levels known to be attained in humans after oral administration of the drug. The effects were associated with distinct morphological changes. Transient exposure of ring-stage parasites to 2.5 microM CLT for a period of 12 hr caused a delay in development in a fraction of parasites that reverted to normal after drug removal; 24-hr exposure to the same concentration caused total destruction of parasites and parasitized cells. Chloroquine antagonized the effects of CLT whereas mefloquine was synergistic. The present study suggests that CLT holds much promise as an antimalarial agent and that it is suitable for a clinical study in P. falciparum malaria.
The aim of this study was to investigate the antimicrobial activity of currently available topical skin pharmaceuticals against Candida albicans, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pyogenes. The agar dilution assay was used to determine the minimal inhibitory concentration for cream formulations and their active substances. Corticosteroid formulations with the antiseptics clioquinol or halquinol were active against all microbes. The hydrogen peroxide formulation was primarily active against staphylococci. Clotrimazole, miconazole and econazole showed an effect against staphylococci in addition to their effect on C. albicans. In contrast, terbinafine had no antibacterial effect. Fusidic acid was active against staphylococci, with slightly weaker activity against S. pyogenes and no activity against C. albicans or E. coli. In summary, some topical skin pharmaceuticals have broad antimicrobial activity in vitro, clioquinol and halquinol being the most diverse. In limited superficial skin infection topical treatment can be an alternative to systemic antibiotics and should be considered. With the global threat of multi-resistant bacteria there is a need for new, topical, non-resistance-promoting, antimicrobial preparations for the treatment of skin infections.
Azoles are important compounds for the treatment of fungal infections. This review focuses on three azoles: isavuconazole, ravuconazole and albaconazole (Stiefel). These drugs exhibit a broad spectrum of activity in vitro, including activity against several fungal isolates that are resistant to other azoles. However, poor or limited activity of these compounds has been demonstrated against species of Fusarium and Scedosporium, as well as against Zygomycetes. As isavuconazole and ravuconazole have been developed both as intravenous and oral formulations, these compounds are suitable candidates for the treatment of various invasive fungal diseases. Most clinical trials with albaconazole have targeted mucocutaneous fungal infections. Although all of these agents appear to be well tolerated, cross-resistance is a concern in the azole family of compounds.
The rate and equilibrium constants for the information of a number of metmyoglobin species Mb+X (X = imidazole, imidazole-H-, 1-methylimidazole, 2-methylimidazole, 4-nitroimidazole, 2-methyl-5-nitroimidazole, pyridine, 2-, 3-, and 4-picoline) and the rates of their reduction by dithionite have been measured at 25 degrees. Several different kinds of kinetic behavior for the reduction were observed. In all cases, a rate constant for direct reaction of Mb+X with SO2- can be assessed. The data strongly support attack of SO2- on the ligand, followed by electron transfer through the pi system to the metal ion.
The interaction of azole antifungal antibiotics with purified Candida albicans cytochrome P-450-dependent 14 alpha-sterol demethylase (P-450DM) was measured spectrophotometrically and by inhibition of enzyme activity. Ketoconazole and ICI 153066 (a triazole derivative) formed low-spin complexes with the ferric cytochrome and induced type II difference spectra. These spectra are indicative of an interaction between the azole moiety and the sixth co-ordination position of P-450DM haem. Both azoles inhibited the binding of CO to the sodium dithionite-reduced ferrous cytochrome, and inhibited reconstituted P-450DM activity by binding to the cytochrome with a one-to-one stoichiometry. Similarly, total inhibition of enzyme activity occurred when equimolar amounts of clotrimazole, miconazole or fluconazole were added to reconstituted P-450DM. These results correlated with the inhibition of P-450DM in broken cell preparations, confirming that all five azoles are potent inhibitors of ergosterol biosynthesis in C. albicans.
Pathologic water loss from sickle erythrocytes concentrates the abnormal hemoglobin and promotes sickling. The Ca2+-activated K+ channel (Gardos channel) contributes to this deleterious dehydration in vitro, and blockade of K+ and water loss via this channel could be a potential therapy in vivo. We treated five subjects who have sickle cell anemia with oral clotrimazole, a specific Gardos channel inhibitor. Patients were started on a dose of 10 mg clotrimazole/kg/d for one week. Protocol design allowed the daily dose to be escalated by 10 mg/kg each week until significant changes in erythrocyte density and K+ transport were achieved. Blood was sampled three times a week for hematological and chemical assays, erythrocyte density, cation content, and K+ transport. At dosages of 20 mg clotrimazole/kg/d, all subjects showed Gardos channel inhibition, reduced erythrocyte dehydration, increased cell K+ content, and somewhat increased hemoglobin levels. Adverse effects were limited to mild/moderate dysuria in all subjects, and a reversible increase in plasma alanine transaminase and aspartic transaminase levels in two subjects treated with 30 mg clotrimazole/kg/d. This is the first in vivo evidence that the Gardos channel causes dehydration of sickle erythrocytes, and that its pharmacologic inhibition provides a realistic antisickling strategy.
Oropharyngeal candidiasis (OPC) is a common opportunistic infection in human immunodeficiency virus (HIV)-infected patients and other immunocompromised hosts. Clotrimazole troches are widely used in the treatment of mucosal candidiasis. However, little is known about the potential contribution of clotrimazole resistance to the development of refractory mucosal candidiasis. We therefore investigated the potential emergence of resistance to clotrimazole in a prospectively monitored HIV-infected pediatric population receiving this azole. Adapting the National Committee for Clinical Laboratory Standards M27-A reference method for broth antifungal susceptibility testing of yeasts to clotrimazole, we compared MICs in macrodilution and microdilution assays. We further analyzed the correlation between these in vitro findings and the clinical response to antifungal therapy. One isolate from each of 87 HIV-infected children was studied by the macrodilution and microdilution methods. Two inoculum sizes were tested by the macrodilution method (10(3) and 10(4) CFU/ml) in order to assess the effect of inoculum size on clotrimazole MICs. The same isolates also were tested using a noncolorimetric microdilution method. Clotrimazole concentrations ranged from 0.03 to 16 microg/ml. Readings were performed after incubation for 24 and 48 h at 35 degrees C. For 62 (71.2%) of 87 clinical isolates, the MICs were low (< or =0.06 microg/ml). The MIC for 90% of the strains tested was 0.5 microg/ml, and the highest MIC was 8 microg/ml. There was no significant difference between MICs at the two inoculum sizes. There was 89% agreement (+/-1 tube) between the microdilution method at 24 h and the macrodilution method at 48 h. If the MIC of clotrimazole for an isolate of C. albicans was > or =0.5 microg/ml, there was a significant risk (P < 0.001) of cross-resistance to other azoles: fluconazole, > or = 8 microg/ml (relative risk [RR] = 8.9); itraconazole, > or =1 microg/ml (RR = 10). Resistance to clotrimazole was highly associated with clinically overt failure of antifungal azole therapy. Six (40%) of 15 patients for whom the clotrimazole MIC was > or =0.5 microg/ml required amphotericin B for refractory mucosal candidiasis versus 4 (5.5%) of 72 for whom the MIC was <0.5 microg/ml (P = 0.001; 95% confidence interval = 2.3 to 22; RR = 7.2). These findings suggest that an interpretive breakpoint of 0.5 microg/ml may be useful in defining clotrimazole resistance in C. albicans. The clinical laboratory's ability to determine MICs of clotrimazole may help to distinguish microbiologic resistance from the other causes of refractory OPC, possibly reducing the usage of systemic antifungal agents. We conclude that resistance to clotrimazole develops in isolates of C. albicans from HIV-infected children, that cross-resistance to other azoles may develop concomitantly, and that this resistance correlates with refractory mucosal candidiasis.
Cytochrome P450 14alpha-sterol demethylases (CYP51) are essential enzymes in sterol biosynthesis in eukaryotes. CYP51 removes the 14alpha-methyl group from sterol precursors such as lanosterol, obtusifoliol, dihydrolanosterol, and 24(28)-methylene-24,25-dihydrolanosterol. Inhibitors of CYP51 include triazole antifungal agents fluconazole and itraconazole, drugs used in treatment of topical and systemic mycoses. The 2.1- and 2.2-A crystal structures reported here for 4-phenylimidazole- and fluconazole-bound CYP51 from Mycobacterium tuberculosis (MTCYP51) are the first structures of an authentic P450 drug target. MTCYP51 exhibits the P450 fold with the exception of two striking differences-a bent I helix and an open conformation of BC loop-that define an active site-access channel running along the heme plane perpendicular to the direction observed for the substrate entry in P450BM3. Although a channel analogous to that in P450BM3 is evident also in MTCYP51, it is not open at the surface. The presence of two different channels, with one being open to the surface, suggests the possibility of conformationally regulated substrate-in/product-out openings in CYP51. Mapping mutations identified in Candida albicans azole-resistant isolates indicates that azole resistance in fungi develops in protein regions involved in orchestrating passage of CYP51 through different conformational stages along the catalytic cycle rather than in residues directly contacting fluconazole. These new structures provide a basis for rational design of new, more efficacious antifungal agents as well as insight into the molecular mechanism of P450 catalysis.
The advent of the human immunodeficiency virus infection and the increasing prevalence of compromised individuals in the community due to modern therapeutic advances have resulted in a resurgence of opportunistic infections, including oral candidoses. One form of the latter presents classically as a white lesion of "thrush" and is usually easily diagnosed and cured. Nonetheless, a minority of these lesions appears in new guises such as erythematous candidosis, thereby confounding the unwary clinician and complicating its management. Despite the availability of several effective antimycotics for the treatment of oral candidoses, failure of therapy is not uncommon due to the unique environment of the oral cavity, where the flushing effect of saliva and the cleansing action of the oral musculature tend to reduce the drug concentration to sub-therapeutic levels. This problem has been partly circumvented by the introduction of the triazole agents, which initially appeared to be highly effective. However, an alarming increase of organisms resistant to the triazoles has been reported recently. In this review, an overview of clinical manifestations of oral candidoses and recent advances in antimycotic therapy is given, together with newer concepts, such as the post-antifungal effect (PAFE) and its possible therapeutic implications.
Resistance to azole antifungals continues to be a significant problem in the common fungal pathogen Candida albicans. Many of the molecular mechanisms of resistance have been defined with matched sets of susceptible and resistant clinical
isolates from the same strain. Mechanisms that have been identified include alterations in the gene encoding the target enzyme
ERG11 or overexpression of efflux pump genes including CDR1, CDR2, and MDR1. In the present study, a collection of unmatched clinical isolates of C. albicans was analyzed for the known molecular mechanisms of resistance by standard methods. The collection was assembled so that approximately
half of the isolates were resistant to azole drugs. Extensive cross-resistance was observed for fluconazole, clotrimazole,
itraconazole, and ketoconazole. Northern blotting analyses indicated that overexpression of CDR1 and CDR2 correlates with resistance, suggesting that the two genes may be coregulated. MDR1 overexpression was observed infrequently in some resistant isolates. Overexpression of FLU1, an efflux pump gene related to MDR1, did not correlate with resistance, nor did overexpression of ERG11. Limited analysis of the ERG11 gene sequence identified several point mutations in resistant isolates; these mutations have been described previously. Two
of the most common point mutations in ERG11 associated with resistance, D116E and E266D, were tested by restriction fragment length polymorphism analysis of the isolates
from this collection. The results indicated that the two mutations occur frequently in different isolates of C. albicans and are not reliably associated with resistance. These analyses emphasize the diversity of mechanisms that result in a phenotype
of azole resistance. They suggest that the resistance mechanisms identified in matched sets of susceptible and resistant isolates
are not sufficient to explain resistance in a collection of unmatched clinical isolates and that additional mechanisms have
yet to be discovered.
Infections with the sexually transmitted protozoan Trichomonas vaginalis are usually treated with metronidazole, a 5-nitroimidazole drug derived from the antibiotic azomycin. Metronidazole treatment is generally efficient in eliminating T. vaginalis infection and has a low risk of serious side effects. However, studies have shown that at least 5% of clinical cases of trichomoniasis are caused by parasites resistant to the drug. The lack of approved alternative therapies for T. vaginalis treatment means that higher and sometimes toxic doses of metronidazole are the only option for patients with resistant disease. Clearly, studies of the treatment and prevention of refractory trichomoniasis are essential. This review describes the mechanisms of metronidazole resistance in T. vaginalis and provides a summary of trichomonicidal and vaccine candidate drugs.
The mechanism of antimalarial activity of clotrimazole was studied placing emphasis on its role in inhibiting hemoperoxidase for inducing oxidative stress in Plasmodium falciparum. Clotrimazole, in the presence of H2O2, causes irreversible inactivation of the enzyme, and the inactivation follows pseudo-first order kinetics, consistent with a mechanism-based (suicide) mode. The pseudo-first order kinetic constants are ki = 2.85 microM, k(inact) = 0.9 min(-1), and t(1/2) = 0.77 min. The one-electron oxidation product of clotrimazole has been identified by EPR spectroscopy as the 5,5'-dimethyl-1-pyrroline N-oxide (DMPO) adduct of the nitrogen-centered radical (aN = 15 G), and as DMPO protects against inactivation, this radical is involved in the inactivation process. Binding studies indicate that the clotrimazole oxidation product interacts at the heme moiety, and the heme-clotrimazole adduct has been dissociated from the inactivated enzyme and identified (m/z 1363) by mass analysis. We found that the inhibition of hemoperoxidase increases the accumulation of H2O2 in P. falciparum and causes oxidative stress. Furthermore, the inhibition of hemoperoxidase correlates well with the inhibition of parasite growth. The results described herein indicate that the antimalarial activity of clotrimazole might be due to the inhibition of hemoperoxidase and subsequent development of oxidative stress in P. falciparum.
Clotrimazole (CLT) is an antimycotic imidazole derivative that is known to inhibit cytochrome P-450, ergosterol biosynthesis and proliferation of cells in culture, and to interfere with cellular Ca(2+) homeostasis. We found that CLT inhibits the Ca(2+)-ATPase of rabbit fast-twitch skeletal muscle (SERCA1), and we characterized in detail the effect of CLT on this calcium transport ATPase. We used biochemical methods for characterization of the ATPase and its partial reactions, and we also performed measurements of charge movements following adsorption of sarcoplasmic reticulum vesicles containing the ATPase onto a gold-supported biomimetic membrane. CLT inhibits Ca(2+)-ATPase and Ca(2+) transport with a K(I) of 35 mum. Ca(2+) binding in the absence of ATP and phosphoenzyme formation by the utilization of ATP in the presence of Ca(2+) are also inhibited within the same CLT concentration range. On the other hand, phosphoenzyme formation by utilization of P(i) in the absence of Ca(2+) is only minimally inhibited. It is concluded that CLT inhibits primarily Ca(2+) binding and, consequently, the Ca(2+)-dependent reactions of the SERCA cycle. It is suggested that CLT resides within the membrane-bound region of the transport ATPase, thereby interfering with binding and the conformational effects of the activating cation.
Pathogenic yeasts from the genus Candida can cause serious infection in humans particularly, in immunocompromised patients and are now recognized as major agents of hospital acquired (nosocomial) infections. In the recent years, there has been a marked increase in the incidence of treatment failures in candidiasis patients receiving long-term antifungal therapy, which has posed a serious problem in its successful use in chemotherapy. Candida cells acquire drug resistance (MDR) during the course of the treatment. The mechanisms of resistance to azole antifungal agents have been elucidated in Candida species and can be mainly categorized as (i) changes in the cell wall or plasma membrane, which lead to impaired drug (azole) uptake; (ii) alterations in the affinity of the drug target Erg11p (lanosterol 14alpha-demethylase) especially to azoles or in the cellular content of Erg11p due to target site mutation or overexpression of the ERG11 gene; and (iii) the efflux of drugs mediated by membrane transport proteins belonging to the ATP-binding cassette (ABC) transporters, namely CDR1 and CDR2 or to the major facilitator superfamily (MFS) transporter, CaMDR1. Many such manifestations are associated with the formation of Candida biofilms including those occurring on devices like indwelling intravascular catheters. Biofilm-associated Candida show uniform resistance to a wide spectrum of antifungal drugs. A combination of different resistance mechanisms is responsible for drug resistance in clinical isolates of Candida species.
New antifungals are needed in the medicine because of more aggressive and invasive diagnostic and therapeutic methods used, rapid emergence of resistant and new opportunistic fungi, increasing number of patients suffering from immunosuppressive situations e.g., AIDS, transplantation, cancer, etc. Several classes of new antifungal agents are discussed here including some new members of known families. Voriconazole, posaconazole and ravuconazole, are novel triazoles that inhibit the ergosterol synthesis. These drugs overcome problems associated with the ineffectivity of fluconazole against some Aspergillus spp. or the variable bioavailability of itraconazole. Echinocandins (caspofungin, anidulafungin and micafungin) represent a new family of antifungal agents that inhibit 1,3-beta-glucan synthase. Nikkomycins targeting the chitin synthase, show activity against Histoplasma capsulatum and Blastomyces dermatitidis. Sordarin derivatives that block the fungal protein synthesis can be considered as a promising new class of antifungal agents for the treatment of Candida and Pneumocystis infections.
Buccal bioadhesive films, releasing topical drugs in the oral cavity at a slow and predetermined rate, provide distinct advantages over traditional dosage forms. The aim of present study was to prepare and evaluate buccal bioadhesive films of clotrimazole for oral candidiasis. The film was designed to release the drug at a concentration above the minimum inhibitory concentration for a prolonged period of time so as to reduce the frequency of administration of the available conventional dosage forms. The different proportions of sodium carboxymethylcellulose and carbopol 974P (CP 974P) were used for the preparation of films. Carbopol was used to incorporate the desired bioadhesiveness in the films. The films were prepared by solvent casting method and evaluated for bioadhesion, in vitro drug release and effectiveness against Candida albicans. In vitro drug release from the film was determined using a modified Franz diffusion cell while bioadhesiveness was evaluated with a modified two-arm balance using rabbit intestinal mucosa as a model tissue. Films containing 5% CP 974P of the total polymer were found to be the best with moderate swelling along with favorable bioadhesion force, residence time and in vitro drug release. The microbiological studies revealed that drug released from the film could inhibit the growth of C. albicans for 6 h. The drug release mechanism was found to follow non-Fickian diffusion.
The ability of opportunistic pathogenic Candida species to persist and invade specific niches in the human host depends on their resistance to natural growth inhibitors and antifungal therapy. This work describes the role of the Candida glabrata drug:H(+) antiporter CgTpo3 (ORF CAGL0I10384g) in this context.
Deletion and cloning of CgTPO3 was achieved using molecular biology tools. C. glabrata strain susceptibility was assayed based on growth in liquid and solid media and through MIC determination. Radiolabelled compound accumulation or HPLC were used for the assessment of the role of CgTpo3 as a drug or polyamine transporter. Quantitative RT-PCR was used for expression analysis.
CgTpo3 was found to confer resistance to azole drugs in C. glabrata. This protein was found to be localized to the plasma membrane and to decrease the intracellular accumulation of [(3)H]clotrimazole, playing a direct role in its extrusion from pre-loaded C. glabrata cells. CgTPO3 was further found to confer resistance to spermine, complementing the susceptibility phenotypes exhibited by the deletion of its Saccharomyces cerevisiae homologue, TPO3. In spermine-stressed C. glabrata cells, CgTPO3 is transcriptionally activated in a CgPdr1-dependent manner, contributing to a decrease in the intracellular concentration of this polyamine. Clotrimazole exposure was found to lead to the intracellular accumulation of spermine, and pre-exposure to this polyamine was found consistently to lead to increased clotrimazole resistance.
Altogether, these results point to a significant role for CgTpo3 in azole drug resistance and in the tolerance to high polyamine concentrations, such as those found in the urogenital tract.
This study investigates fabrication of clotrimazole (CZ)-composited electrospun Polyvinylpyrrolidone/Hydroxypropyl-β-cyclodextrin (PVP/HPβCD) blended nanofiber mats for oral candidiasis applications.
PVP/HPβCD blended nanofiber mats containing clotrimazole were electrospun and characterized using SEM, DSC and XRPD. The solvent system ethanol: water: benzyl alcohol (EtOH:H2O:BzOH) with a 70:20:10 ratio was optimal for the electrospinning process. Various amounts of CZ were loaded into the nanofiber mats. The nanofiber mats was further investigated for drug release, antifungal activity and cytotoxicity.
The fiber diameters in the mats were in the nanometer range. The DSC and XRPD revealed a molecular dispersion of amorphous CZ in the nanofiber mats. The loading capacity increased when CZ content was raised. A fast dissolved and released of CZ from the nanofibers mat was achieved. The ability of the CZ-loaded nanofiber mats to kill the Candida depended on the amount of CZ in the mats; moreover, the CZ-loaded nanofibers killed the Candida significantly faster than the CZ powder and lozenges with low cytotoxicity.
CZ-loaded nanofiber mats were successfully electrospun. They exhibited rapid antifungal activity in vitro relative to CZ powder and lozenges. Further in vivo studies are needed to investigate for their application in oral candidiasis.
Oxymyoglobin reacts with imidazole, substituted imidazoles, and hydroquinone to give metmyoglobin. The kinetics of these reactions have been studied. The rates are first order in both reactants, and second-order rate constants are reported. At pH 8.2, k1 for imidazole is 2.5 ± 0.3 × 10−3 M−1 sec−1 and for hydroquinone is 4 ± 0.4 × 10−1 M−1 sec−1. The rates are independent of pH for imidazole but increase rapidly with pH for hydroquinone. The mechanism for all these reactions is thought to involve the two-electron reduction of molecular oxygen to peroxide with concurrent oxidation of both the protein and the reactant. An analogous mechanism has been suggested previously [1] for the reaction of oxyhemoglobin with hydroquinone. It has previously been shown [6] that imidazole can mediate the transfer of electrons to heme proteins by forming a transient reduced radical. The present results indicate that it can also form a transient oxidized radical under mild conditions. This dual capability may be important in biological electron-transfer processes.
Nanopharmaceuticals have the potential to revolutionise medical treatment by permitting the design of more potent, less toxic "smart" therapeutics, ultimately leading to personalised medicine. This review summarises the challenges and potential uses of nanodelivery system for the topical drug therapy of vaginal diseases. The vaginal route of drug administration remains a challenge in the development of novel drug therapies, including nanomedicines. We attempted to provide an unbiased overview of currently investigated nanodelivery systems, some of which remain to be extensively studied under laboratory conditions, and some of which are already in clinical trials. Most nanodelivery systems are aimed at improving the treatment of vaginal infections, including HIV prevention. Promising new approaches in nanopharmaceutical design are discussed in this review, as well as the controversies related to mucoadhesiveness of nanopharmaceuticals.
Invasive fungal infections are an important cause of morbidity and mortality in immunocompromised children. Increases in the incidence of systemic mycoses have been observed during the last 2 decades. Treatment of invasive fungal infections has improved through a better knowledge and application of current treatment strategies and through the development of new antifungal compounds. The purpose of this review is to provide antifungal treatment recommendations for pediatric patients that can help clinicians find the most suitable treatment for each specific case.
New trans-platinum complexes of clotrimazole (CTZ) have been prepared and characterized. Their interaction with DNA and activity against
tumour cell lines were evaluated. [Pt (CTZ)2I2] (1) was synthesized by the reaction of K2PtCl4, KI and CTZ, and [Pt(CTZ)2Cl2] (2) by direct reaction of K2PtCl4 with CTZ. These complexes were characterized by a combination of elemental analysis, molar conductivity, UV–Vis, IR, and
NMR spectroscopy in one and two dimensions. DNA–platinum complex interactions were studied by spectroscopic, thermal denaturation
and viscosity titration measurements. Covalent interaction studies were also performed. From these results we suggest that
complexes 1 and 2 interact with the minor groove of DNA. Both complexes showed growth inhibitory effects on four out of the six tumour cells
lines with GI50 (50% growth inhibition) values in the 5–25μM range, but there was no indication of cytotoxicity over the range of concentrations
tested.
Cell adhesion molecules play a pivotal role in chronic inflammation and pathological angiogenesis. In the present study, we investigated the inhibitory effects of clotrimazole (CLT) on tumor necrosis factor (TNF)-alpha-induced changes in adhesion molecule expression. CLT dose-dependently inhibited monocyte chemoattractant protein-1 (MCP-1), intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) expressions in TNF-alpha-stimulated HT29 colonic epithelial cells. This inhibitory action of CLT correlated with a significant reduction in TNF-alpha-induced adhesion of monocytes to HT29 cells, which was comparable to the inhibitory effects of anti-ICAM-1 and VCAM-1 monoclonal antibodies on monocyte-epithelial adhesion. These inhibitory actions of CLT were, at least in part, attributable to the inhibition of redox sensitive NF-kappaB activation, as CLT inhibited TNF-alpha-induced ROS generation as well as NF-kappaB nuclear translocation and activation in HT29 cells. Furthermore, the inhibition of TNF-alpha-induced monocyte adhesion was also mimicked by the specific NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC). Inflammatory mediators including TNF-alpha have known to promote angiogenesis, which in turn further contributes to inflammatory pathology. Therefore, we additionally evaluated whether CLT modulates TNF-alpha-induced angiogenesis using in vivo chick chorioallantoic membrane (CAM) assay. The CAM assay showed that CLT dose-dependently attenuated TNF-alpha-induced angiogenesis, and the effect was correlated with decreased inflammation of the CAM tissue. In conclusion, our results suggest that CLT can inhibit TNF-alpha-triggered expression of adhesion molecules, ICAM-1 and VCAM-1, and angiogenesis during inflammation.
The ergosterol biosynthesis-inhibiting (EBI) antifungals constitute the most important group of compounds developed for the control of fungal diseases in man. Currently, representatives of two classes of EBI antifungals are available: the squalene epoxidase inhibitors and those that interfere with cytochrome P450-dependent ergosterol synthesis. The allylamines (eg, terbinafine) inhibit squalene epoxidase in sensitive fungi, Trichophyton mentagrophytes being the most sensitive species. The most important developments have come from the introduction of the N-substituted imidazoles and triazoles, the so-called azole antifungals. Most of the currently available imidazoles (eg, miconazole, clotrimazole, econazole) and the triazole derivative terconazole are mainly for topical treatment. Ketoconazole was the first azole derivative orally active against yeasts, dermatophytes and dimorphic fungi. The new triazole, itraconazole, appears to be among the most promising orally active systemic agents. All the azole antifungals inhibit the cytochrome P450-dependent, 14 alpha-demethylase, a key enzyme in the synthesis of ergosterol, the main sterol in most fungal cells. Of all the azoles tested, itraconazole shows the highest affinity for the cytochrome P450 involved. It is about three and ten times more active in vitro than miconazole and the bis-triazole, fluconazole, respectively. Itraconazole's high affinity for the fungal P450 originates from its triazole group as well as from the nonligating lipophilic tail.
A 60-year-old man with allergic contact dermatitis to clotrimazole (Lotrimin) is described. Results of patch tests confirmed the reaction to clotrimazole itself and not the vehicle. After negative results of patch tests to other imidazoles, the patient was treated with econazole without complications. A brief review of contact dermatitis to clotrimazole and other imidazoles is included.
Cell proliferation is critically dependent on the regulated movement of ions across various cellular compartments. The antimycotic drug clotrimazole (CLT) has been shown to inhibit movement of Ca2+ and K+ across the plasma membrane. Our results show that CLT inhibits the rate of cell proliferation of normal and cancer cell lines in a reversible and dose-dependent manner in vitro. Moreover, CLT depletes the intracellular Ca2+ stores and prevents the rise in cytosolic Ca2+ that normally follows mitogenic stimulation. In mice with severe combined immunodeficiency disease (SCID) and inoculated intravenously with MM-RU human melanoma cells, daily subcutaneous injections of CLT induced a significant reduction in the number of lung metastases. Modulation of early ionic mitogenic signals and potent inhibition of cell proliferation both in vitro and in vivo are new and potentially useful clinical effects of CLT.
Clotrimazole (CLT), a member of the antifungal imidazole family of compounds, has been found to inhibit both calcium (Ca2+)-activated 86Rb and potassium (K) fluxes of human red cells and to inhibit red cell binding of 125I-charybdotoxin (ChTX) [11]. We have now used patch-clamp techniques to demonstrate reversible inhibition of whole cell KCa2+ currents in murine erythroleukemia (MEL) cells by submicromolar concentrations of CLT. Inhibition was equivalent whether currents were elicited by bath application of the Ca2+ ionophore A23187 or by dialyzing cells with a pipette solution containing micromolar concentrations of free Ca2+. The extent of inhibition of whole cell MEL KCa2+ currents was voltage-dependent, decreasing with increasing test potential. We also determined the single channel basis of the CLT inhibition in MEL cells by demonstrating the inhibition of a calcium-activated, ChTX-sensitive K channel by CLT in outside-out patches. The channel was also blocked by the des-imidazolyl metabolite of CLT, 2-chlorophenyl-bisphenyl-methanol (MET II) [15], thus demonstrating that the imidazole ring is not required for the inhibitory action of CLT. Single KCa2+ channels were also evident in inside-out patches of MEL cells. Block of K current by CLT was not unique to MEL cells. CLT also inhibited a component of the whole cell K current in PC12 cells. Channel specificity of block by CLT was determined by examining its effects on other types of voltage-sensitive currents. CLT block showed the following rank order of potency: K currents in PC12 cells > Ca2+ currents in PC12 cells > Na currents in sympathetic neurons. These results demonstrate that direct inhibition of single KCa2+ by CLT can be dissociated from inhibition of cytochrome P-450 in MEL cells.
The structure of the title compound, 1-[(2-chlorophenyl)diphenylmethyl]-1H-imidazole, C22H17ClN2, has been determined. The molecular conformation showed a weathercock-type structure and the three phenyl rings are almost perpendicular to the imidazole ring. The distances between the centres of the three phenyl rings and the centre of the imidazole ring are in the range 4.52-4.54 A.
The ionic mechanism of clotrimazole, an imidazole antimycotic P-450 inhibitor, was examined in rat anterior pituitary GH3 cells. In perforated-patch whole-cell recording experiments, clotrimazole reversibly caused an inhibition of the Ca2+-activated K+ current in a dose-dependent manner. The IC50 value of the clotrimazole-induced inhibition of I(K(Ca)) was 3 microM. In the outside-out configuration of single channel recording, application of clotrimazole (10 microM) into the bath medium did not change the single channel conductance of large conductance Ca2+-activated K+(BK(Ca)) channels, but it suppressed the channel activity significantly. The change in the kinetic behavior of BK(Ca) channels caused by clotrimazole in these cells is found to be due to a decrease in mean open time and an increase in mean closed time. Other structurally distinct P-450 inhibitors (e.g. ketoconazole or econazole) also effectively suppressed the amplitude of I(K(Ca)). Clotrimazole (10 microM) blocked both the inactivating and non-inactivating components of the voltage-dependent K+ outward current (I(K(V))), but it produced a slight reduction of L-type Ca2+ inward current (I(Ca,L)) without altering the current-voltage relationship of I(Ca,L). Clotrimazole (10 microM) also increased the firing rate of action potentials. These results provide direct evidence that clotrimazole is capable of suppressing the activity of BK(Ca) channel in GH3 cells. Because of the non-selective inhibitory effect of clotrimazole on I(K(Ca)) and I(K(V)), this inhibition is mainly, if not entirely, due to a direct channel blockade. Thus, the present study implies that the blockade of these ionic channels by clotrimazole would affect hormonal secretion and neuronal excitability.
The effect of clotrimazole on Ca2+ signaling in Madin Darby canine kidney (MDCK) cells was investigated by using fura-2 as a Ca2+ indicator. Clotrimazole (1-30 microM) induced a concentration-dependent [Ca2+]i increase. The [Ca2+]i increase comprised an initial rise and a slow decay. External Ca2+ removal partly inhibited the Ca2+ signals by reducing both the initial rise and the decay phase, indicating that clotrimazole triggered both Ca2+ influx and Ca2+ release. Pretreatment with 30 microM clotrimazole in Ca2+-free medium abolished the Ca2+ release induced by thapsigargin (1 microM), an endoplasmic reticulum Ca2+ pump inhibitor, and conversely, pretreatment with thapsigargin prevented clotrimazole from releasing more Ca2+. This suggests that the thapsigargin-sensitive Ca2+ store is the source of clotrimazole-induced Ca2+ release. Clotrimazole (10 microM) triggered Mn2+ quench of fura-2 fluorescence which was partly inhibited by 1 mM La3+. Addition of 3 mM Ca2+ induced a [Ca2+]i increase after preincubation with 10 microM clotrimazole in Ca2+-free medium, indicating that clotrimazole activated capacitative Ca2+ entry. However, 10 and 30 microM clotrimazole inhibited 1 microM thapsigargin-induced capacitative Ca2+ entry by 21% and 74%, respectively. Pretreatment with 40 microM aristolochic acid to inhibit phospholipase A2 reduced 30 microM clotrimazole-induced Ca2+ release by 51%, but inhibiting phospholipase C with 2 microM U73122 had little effect. This implies that clotrimazole induces Ca2+ release in an IP3-independent manner, which could be modulated by phospholipase A2-coupled events.
The pharmacology of the slow afterhyperpolarization (sAHP) was studied in cultured rat hippocampal pyramidal neurones.
Clotrimazole, its in vivo metabolite, 2‐chlorophenyl‐bisphenyl‐methanol (CBM) and the novel analogues, UCL 1880 and UCL 2027, inhibited the sI AHP with similar IC 50 s (1 – 2 μ M ).
Clotrimazole and CBM also inhibited the high voltage‐activated (HVA) Ca ²⁺ current in pyramidal neurones with IC 50 s of 4.7 μ M and 2.2 μ M respectively. UCL 1880 was a less effective Ca ²⁺ channel blocker, reducing the HVA Ca ²⁺ current by 50% at 10 μ M . At concentrations up to 10 μ M , UCL 2027 had no effect on the Ca ²⁺ current, indicating that its effects on the sI AHP were independent of Ca ²⁺ channel block.
Clotrimazole also inhibited both the outward holding current (IC 50 =2.8 μ M ) present at a potential of −50 mV and the apamin‐sensitive medium AHP (mAHP; IC 50 ∼amp;10 μ M ). The other clotrimazole analogues tested had smaller effects on these two currents. The present work also shows that 100 n M UCL 1848, an inhibitor of apamin‐sensitive conductances, abolishes the mAHP.
Currents were recorded from HEK293 cells transfected with hSK1 and rSK2. The SK currents were very sensitive to inhibition by UCL 1848 but were not significantly reduced by the sI AHP inhibitor, UCL 2027 (10 μ M ). 10 μ M UCL 1880 reduced the hSK1 current by 40%.
UCL 2027 appears to be the first relatively selective blocker of the sAHP to be described. Furthermore, the ability of UCL 2027 to block the sAHP with minimal effect on SK1 channel activity questions the role of this channel in the sAHP.
British Journal of Pharmacology (2001) 132 , 889–898; doi: 10.1038/sj.bjp.0703895
Clinical needs for novel antifungal agents have altered steadily with the rise and fall of AIDS-related mycoses, and the change in spectrum of fatal disseminated fungal infections that has accompanied changes in therapeutic immunosuppressive therapies. The search for new molecular targets for antifungals has generated considerable research using modern genomic approaches, so far without generating new agents for clinical use. Meanwhile, six new antifungal agents have just reached, or are approaching, the clinic. Three are new triazoles, with extremely broad antifungal spectra, and three are echinocandins, which inhibit synthesis of fungal cell wall polysaccharides--a new mode of action. In addition, the sordarins represent a novel class of agents that inhibit fungal protein synthesis. This review describes the targets and mechanisms of action of all classes of antifungal agents in clinical use or with clinical potential.
The classical pathway for induction of cytochrome P4501A (CYP1A) by xenobiotics is ligand binding to the aryl hydrocarbon receptor (AhR). High-affinity AhR ligands are planar polyaromatic molecules such as the prototypic ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The present work investigated the ability of the imidazole derivative, clotrimazole [1-(2'chlorotrityl)imidazole, CLO], to induce CYP1A in cultured rainbow trout (Oncorhynchus mykiss) hepatocytes at the catalytic activity (determined as 7-ethoxyresorufin-O-deethylase, EROD) and at the transcriptional level. CLO resulted in a significant increase of hepatocyte EROD activity and CYP1A mRNA at a concentration of 1.56 microM. Computational studies on the molecular structure of CLO show that CLO is unlikely to take a planar conformation. Further indications that CLO does not behave like a planar AhR ligand come from the experimental observation that co-incubation of trout hepatocytes with CLO and the AhR antagonist, alpha-naphthoflavone (alpha-NF), did not result in an inhibition of CLO induction of CYP1A mRNA, whereas alpha-NF was able to inhibit CYP1A induction by the prototpyic, planar AhR ligand, beta-naphthoflavone. The experimental findings on CLO agree with previous results obtained for another non-planar imidazole derivative, 1-benzylimidazole (BIM). Further, computational studies showed that the non-planar imidazoles, BIM and CLO, are highly similar with respect to some electrostatic properties, namely the dipole moment and the molecular electrostatic potential (MEP). Overall our experimental and computational studies suggest that transcriptional activation of CYP1A by the imidazole derivatives CLO and BIM is mediated by a mechanism different to that of prototypic CYP1A inducers such as the planar AhR-ligands.
The antifungal antibiotic clotrimazole (CLT) shows therapeutic effects on cancer, sickle cell disease, malaria, etc. by inhibiting membrane intermediate-conductance Ca2+-activated K+ channels (IKCa). However, it is unclear whether this drug would affect human cardiac K+ currents. The present study was therefore designed to investigate the effects of CLT on transient outward K+ current (Ito1), and ultra-rapid delayed rectifier K+ current (IKur) in isolated human atrial myocytes, and cloned hERG channel current (IhERG) and recombinant human cardiac KCNQ1/KCNE1 channel current (IKs) expressed in HEK 293 cells.
It was found that CLT inhibited Ito1 with an IC50 of 29.5 μM, accelerated Ito1 inactivation, and decreased recovery of Ito1 from inactivation. In addition, CLT inhibited human atrial IKur in a concentration-dependent manner (IC50=7.6 μM).
CLT substantially suppressed IhERG (IC50=3.6 μM), and negatively shifted the activation conductance of IhERG. Moreover, CLT inhibited IKs (IC50=15.1 μM), and positively shifted the activation conductance of the current.
These results indicate that the antifungal antibiotic CLT substantially inhibits human cardiac repolarization K+ currents including Ito1, IKur, IhERG, and IKs. However, caution is recommended when correlating the observed in vitro effects on cardiac ion currents to the clinical relevance.
British Journal of Pharmacology (2006) 147, 289–297. doi:10.1038/sj.bjp.0706590
New palladium complexes of chloroquine (CQ) and clotrimazole (CTZ) have been prepared, characterized, and evaluated against four tumor cell lines in vitro. [Pd (CQ)2Cl2] (1) was synthesized by the reaction of PdCl2(CH3CN)2 with CQ, and the [Pd (CTZ)2Cl2] (2) complex by a similar reaction. The new compounds were characterized by a combination of FAB-MS (fast atom bombardment-mass spectrum), elemental analysis, molar conductivity, IR, and NMR spectroscopy. The solid-state structure of 2 has been determined by X-ray crystallography. 2 crystallizes in the monoclinic space group P(2(1)/c), with a = 21.100(4) A, b = 13.408(3) A, c = 22.642(5) A. The structure refinement converged at R1 = 0.0728, wR2 = 0.1918. The cytotoxicity of these two complexes for the tumor cell lines, PANC-1, SKBR-3, MDA-MB231 and HT-29, was compared with that of the original ligands. Ligation of palladium to CTZ led to an increase in the IC50, although a three-fold reduction in the IC50 of CQ was observed on ligation to the metal when tested against the MDA-MB231 cell line.
Since clotrimazole, known as an antifungal drug, exerts diverse actions on cellular functions, it is expected that clotrimazole can be used for other purposes. This antifungal drug protects the cells overloaded with Ca(2+) by A23187, a calcium ionophore. Therefore, the agent may prevent the cells from death induced by heavy metals such as CdCl(2), PbCl(2), or HgCl(2) that are respectively proposed to increase intracellular Ca(2+) concentration. To test this possibility, we have examined the effect of clotrimazole on the cells simultaneously treated with CdCl(2), PbCl(2), or HgCl(2) using rat thymocytes and a flow cytometer with fluorescent probes. The simultaneous application of clotrimazole and CdCl(2) significantly decreased cell viability, even though the concentrations of both were ineffective at affecting the viability. The significant decrease in cell viability was not due to the inhibition of Ca(2+)-ATPase and Ca(2+)-dependent K(+) channels that were induced by clotrimazole. The simultaneous application increased the population of cells with phosphatidylserine exposed on membrane surface, indicating the change in asymmetrical distribution of membrane phospholipids. Furthermore, the cytotoxicity induced by the combination of clotrimazole and CdCl(2) under nominally Ca(2+)-free condition was more profound than that under normal Ca(2+) condition. Therefore, the membrane may be a target for the cytotoxic action of clotrimazole and CdCl(2) that were simultaneously applied. It is also the case for PbCl(2), but not the case for HgCl(2). It is concluded that clotrimazole can modulate the cytotoxicity of some heavy metals.
Identification of new molecular scaffolds structurally unrelated to known antimalarials may represent a valid strategy to overcome resistance of P. falciparum (Pf) to currently available drugs. We describe herein the investigation of a new polycyclic pharmacophore, related to clotrimazole, to develop innovative antimalarial agents. This study allowed us to discover compounds characterized by a high in vitro potency, particularly against Pf CQ-resistant strains selectively targeting free heme, which are easy to synthesize by low-cost synthetic strategies.
Following the generation of transgenic mouse models of sickle cell disease, pre-clinical trials have shown the beneficial effects of various potential therapeutic molecules for the acute or chronic manifestations of the disease. Several molecules are upon evaluation in phase I to phase III clinical trials. These therapeutic approaches target: 1) membrane cation transport systems and channels involved in sickle cell dehydration; 2) adherence of erythrocytes to endothelium; 3) activation of circulating and endothelial cells participating in the vasoocclusive events and local ischemia. The Gardos channel (calcium activated potassium channel KCNN4) is inhibited by the clotrimazole metabolite ICA17043, in phase III trial. The K-Cl co-transport (KCC1/3/4) activated by the depletion of erythrocyte magnesium is inhibited by Magnesium pidolate; dipyridamole inhibits ion transports upon deoxygenation. Sulfasalazyne (inhibitor of the NF-jB pathway) inhibits the abnormal activation of endothelial cells. Nitric oxide (NO) is the most potent vasodilator. It prevents the activation of leucocytes, platelets and endothelial cells in patients with sickle cell disease and vascular remodelling. The L-arginine, the NO precursor, provides could be beneficial in sickle cell patients.
Many kinds of radicals are stable enough to isolate, handle, and store without any special precautions. The diversity in molecular architectures of these stable radicals is sufficiently large that the common factors governing radical stability/persistence, geometric and electronic structure, association/dimerization preferences, and reactivity have generally not been well articulated or appreciated. This review provides a survey of the major classes of stable or persistent organic/organomain group radicals with a view to presenting a unified description of the interdependencies between radical molecular structure and properties.
Despite therapeutic advances, vulvovaginal candidosis remains a common problem worldwide, affecting all strata of society. Understanding of anti-candida host defence mechanisms in the vagina has developed slowly and, despite a growing list of recognised risk factors, a fundamental grasp of pathogenic mechanisms continues to elude us. The absence of rapid, simple, and inexpensive diagnostic tests continues to result in both overdiagnosis and underdiagnosis of vulvovaginal candidosis. I review the epidemiology and pathogenesis of this infection, and also discuss management strategies.
Pathogenic Candida species remain a significant medical problem despite the availability of antifungal therapies. Two key issues must be addressed to improve the treatment of life-threatening systemic Candida infections. First, advanced diagnostic tools are required to facilitate the early identification of these infections, when therapeutic intervention is more likely to be effective. Second, improved antifungal therapies are needed. These therapies, which might include combinations of antifungals, need to be less toxic to the patient and more potent in killing a broader range of Candida species. Recent advances in unravelling the genomics of these species should facilitate efforts to achieve these goals. We discuss the contribution of genomics to the development of novel antifungals and new diagnostic tools.
There has been an increase in rare mould infections in recent decades. These infections have been reported primarily in severely immunocompromised patients. The emergence of these organisms is multifactorial and can be related to more intense immunosuppression, the prolonged survival of patients who have what were previously fatal diseases, and the selective pressure of broad spectrum antifungal agents used for prophylaxis or therapy. Among these rare mould infections, the Zygomycetes are the most commonly encountered, and in some institutions the increase in these organisms appears to be associated with the use of voriconazole. Aspergillus terreus, a species that is resistant to amphotericin B, and less frequently, A. ustus and A. lentulus, have been noted increasingly as causes of invasive aspergillosis in tertiary care centres in the US. Several species of Scedosporium with innate resistance to many antifungal agents have emerged as major causes of disseminated mould infections that are frequently very difficult to treat. Among patients who have haematological malignancies, are neutropenic or have received a haematopoietic stem cell transplant, infections due to Fusarium species respond poorly to many antifungal agents. Dematiaceous, or brown-black, fungi, most often associated with chronic localised infections, are now increasingly reported as a cause of disseminated infection in immunosuppressed hosts.
Concomitant with the increased number of infections with these rare moulds, several new mould-active antifungal agents have been developed. The new expanded spectrum azole, voriconazole, has changed our approach to moulds such as S. apiospermum, Fusarium species and A. terreus that are amphotericin B resistant. Posaconazole, the most recently approved expanded spectrum azole, is the first drug in the azole class to show activity against the Zygomycetes and has proven extremely useful for step-down therapy after initial treatment with amphotericin B. It is not known whether posaconazole is effective as primary therapy for zygomycosis; the use of this agent for that purpose awaits clinical trials with the recently developed intravenous formulation of posaconazole.
We describe herein the design, synthesis, biological evaluation, and structure-activity relationship (SAR) studies of an innovative class of antimalarial agents based on a polyaromatic pharmacophore structurally related to clotrimazole and easy to synthesize by low-cost synthetic procedures. SAR studies delineated a number of structural features able to modulate the in vitro and in vivo antimalarial activity. A selected set of antimalarials was further biologically investigated and displayed low in vitro toxicity on a panel of human and murine cell lines. In vitro, the novel compounds proved to be selective for free heme, as demonstrated in the beta-hematin inhibitory activity assay, and did not show inhibitory activity against 14-alpha-lanosterol demethylase (a fungal P450 cytochrome). Compounds 2, 4e, and 4n exhibited in vivo activity against P. chabaudi after oral administration and thus represent promising antimalarial agents for further preclinical development.
Martindale: the complete drug reference
- S C Sweetman
Sweetman, S.C.(eds) (2007). Martindale: the complete drug
reference. p. 764. London: Pharmaceutical Press.