Degradation of the endoplasmic reticulum-anchored transcription factor MyRF by the ubiquitin ligase SCFFbxw7 in a manner dependent on the kinase GSK-3.

The ubiquitin-proteasome system regulates the abundance of many cellular proteins by mediating their targeted degradation. We previously developed a method-differential proteomics-based identification of ubiquitylation substrates (DiPIUS)-for the comprehensive identification of substrates for a given F-box protein subunit of SCF-type ubiquitin ligases. We have now applied DiPIUS to the F-box protein Fbxw7 in three cell lines (mHepa, Neuro2A, and C2C12) and thereby identified myelin regulatory factor (MyRF), an endoplasmic reticulum-anchored transcription factor that is essential for myelination of nerves in the central nervous system, as a candidate substrate of Fbxw7 specifically in mHepa cells. Co-immunoprecipitation analysis confirmed that the NH2-terminal cytoplasmic domain of MyRF interacted with Fbxw7 in these cells. Furthermore, an in vitro ubiquitylation assay revealed that MyRF undergoes polyubiquitylation in the presence of purified recombinant SCFFbxw7 In addition, the stability of MyRF in mHepa cells was increased by mutation of a putative phosphodegron sequence or by exposure of the cells to an inhibitor of glycogen synthase kinase-3 (GSK-3). We found that MyRF mRNA is not restricted to the central nervous system but is instead distributed widely among mouse tissues. Furthermore, with the use of RNA sequencing in mHepa cells overexpressing or depleted of MyRF, we identified many novel potential target genes of MyRF. Our results thus suggest that Fbxw7 controls the transcription of MyRF target genes in various tissues through regulation of MyRF protein stability in a manner dependent on MyRF phosphorylation by GSK-3.

Study to compare the efficacy and safety of fluconazole cream with flutrimazole cream in the treatment of superficial mycosis: a multicentre, randomised, double-blind, phase III trial.

Fluconazole, which is a drug of the azole family, is safely used in systemic treatment of oral and intravenous injection, but it is difficult to use fluconazole as a topical application because of its large molecular weight and strong hydrophilic property. This study is a multicentre, double-blind, randomised, non-inferiority study to compare the antifungal effect and safety of fluconazole cream 0.5% and 1% with flutrimazole cream 1% in superficial mycosis. A total of 162 subjects selected to participate in this study were equally divided into three groups and assigned to be given fluconazole cream 0.5%, fluconazole cream 1%, and flutrimazole cream 1% in the ratio of 1 : 1. The primary index of drug efficacy was determined by complete mycological cure in which no fungus was detected on KOH smear test 4 weeks after application of fluconazole. The secondary index of efficacy was defined as complete mycological cure 4 weeks after the application of fluconazole, improvement of clinical symptoms and overall effectiveness assessed by the research staff. According to this study, on comparing the efficacy of cure of superficial dermatomycosis after 4 weeks of application, both fluconazole 0.5% and fluconazole 1% cream were found to be equally effective and non-inferior to flutrimazole 1% cream. Given the effectiveness and safety of the drug, both fluconazole 0.5% and 1% cream might be said to be optimal concentration in the treatment of superficial dermatomycosis.

Clotrimazole scaffold as an innovative pharmacophore towards potent antimalarial agents: design, synthesis, and biological and structure-activity relationship studies.

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.

Design and synthesis of potent antimalarial agents based on clotrimazole scaffold: exploring an innovative pharmacophore.

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.

Sensitive and selective LC-MS/MS assay for quantitation of flutrimazole in human plasma.

OBJECTIVE: A highly sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of flutrimazole in human plasma. This study was to investigate the application of sensitive and selective LC-MS/MS method for quantitation of flutrimazole in human plasma. MATERIALS AND METHODS: The analysis and internal standard were extracted with ether and hexane (v:v, 1:1) followed by a rapid isocratic elution with a 0.1% formic acid/methanol (v:v, 20:80) on a C18 column (50 mm × 2.1 mm I.D.) and subsequent analysis by mass spectrometry in the multi-reaction-monitoring mode. The precursor to production transitions of m/z 279.0 → 183.1 and m/z 441.0 → 295.1 were used to measure the analyte and the internal standard. RESULTS: The assay was linear over the concentration range of 0.996-99.6 ng•mL-1 for flutrimazole in human plasma. The lower limit of quantification was 0.996 ng•mL-1 and the extraction recovery was larger than 78.83% for flutrimazole. The inter- and intra-day precision of the method at three concentrations was less than 9.26%. CONCLUSIONS: The LC-MS/MS method was firstly applied to quantitation of flutrimazole in human plasma.

Antifungal activity of silver nanoparticles and clotrimazole against Candida spp

Abstract The aim of present study was calculate the Minimum inhibitory concentrations (MICs) of silver nanoparticles and clotrimazole for Candida species and their interaction by the adaptation of standarized methods. The MICs values of clotrimazole were 9 E-04-3 E-03 ug/ml, 0.1-0.6 ug/ml, 3 E-03- 0.1 ug/ml and 3 E-03-0.3 ug/ml for Candida albicans susceptible to fluconazole, Candida albicans resistance to fluconazole, Candida krusei and Candida parapsilosis respectively. The MICs values of silver nanoparticles were 26.50- 53 ug/ml; 26.50-106 ug/ml; 106-212 ug/ ml and 26.50- 53 ug/ml for Candida albicans susceptible to fluconazole, Candida albicans resistance to fluconazole, Candida krusei and Candida parapsilosis respectively. Synergism between clotrimazole and silver nanoparticles was measured by checkerboard BMD (broth microdilution) test and shown only for C. albicans susceptible to fluconazole because the fractional inhibitory concentrations (FICs) values were 0.07 - 0.15 ug/ml. Indifference was shown for the other species tested because the FICs values were between 0.5 - 2- 3.06 ug/ml. The results suggest synergistic activity depending on the fungus species analysed, however we recommend the incorporation of others measurement methodologies to confirm our results. As for measurement methodologies of MICs of silver nanoparticles and clotrimazole international normative were respected to guarantee reproducible and comparable results.

Wedelolactone enhances osteoblastogenesis by regulating Wnt/ß-catenin signaling pathway but suppresses osteoclastogenesis by NF-κB/c-fos/NFATc1 pathway.

Bone homeostasis is maintained by formation and destruction of bone, which are two processes tightly coupled and controlled. Targeting both stimulation on bone formation and suppression on bone resorption becomes a promising strategy for treating osteoporosis. In this study, we examined the effect of wedelolactone, a natural product from Ecliptae herba, on osteoblastogenesis as well as osteoclastogenesis. In mouse bone marrow mesenchymal stem cells (BMSC), wedelolactone stimulated osteoblast differentiation and bone mineralization. At the molecular level, wedelolactone directly inhibited GSK3ß activity and enhanced the phosphorylation of GSK3ß, thereafter stimulated the nuclear translocation of ß-catenin and runx2. The expression of osteoblastogenesis-related marker gene including osteorix, osteocalcin and runx2 increased. At the same concentration range, wedelolactone inhibited RANKL-induced preosteoclastic RAW264.7 actin-ring formation and bone resorption pits. Further, wedelolactone blocked NF-kB/p65 phosphorylation and abrogated the NFATc1 nuclear translocation. As a result, osteoclastogenesis-related marker gene expression decreased, including c-src, c-fos, and cathepsin K. In ovariectomized mice, administration of wedelolactone prevented ovariectomy-induced bone loss by enhancing osteoblast activity and inhibiting osteoclast activity. Together, these data demonstrated that wedelolactone facilitated osteoblastogenesis through Wnt/GSK3ß/ß-catenin signaling pathway and suppressed RANKL-induced osteoclastogenesis through NF-κB/c-fos/NFATc1 pathway. These results suggested that wedelolacone could be a novel dual functional therapeutic agent for osteoporosis.

Frozen conformers of clotrimazole: reaction of imadazole with 1-Chloro-9-hydroxy-9-phenylxanthene.

1-Chloro-9-hydroxy-9-phenylxanthene reacts with imidazole at 180 degrees to form a 5:1 mixture of the 9-(imidazo-1-yl)- and 9-(imidazo-2-yl)-1-chloro-9-phenylxanthenes. These products lack significant antifungal activity.

Mycosporine-like amino acids in the marine dinoflagellate Gyrodinium dorsum: induction by ultraviolet irradiation.

Cultures of the marine dinoflagellate Gyrodinium dorsum have been exposed to polychromatic radiation (photosynthetically active radiation and UV) from a solar simulator for up to 72 h. Different irradiance spectra in the ultraviolet are produced by inserting cut-off filters between lamp and samples. The mycosporine-like amino acid (MAA) content and composition are investigated by spectroscopic and chromatographic analysis. The study reveals that G. dorsum contains a complex mixture of several aminocyclohexenimine-MAAs and one aminocyclohexenone-MAA. UV irradiation around 320 nm induces an increase in the concentration of all MAAs in the samples. In contrast, exposure to short-wavelength UV-B radiation results in decreased overall MAA production. Furthermore, there is a spectral shift in the absorption of the MAA mixture towards shorter wavelengths, indicating that short-wavelength UV-B induces an altered MAA composition. The amount of MAAs is normalized to the chlorophyll a concentration.

Optimization of 4-aminoquinoline/clotrimazole-based hybrid antimalarials: further structure-activity relationships, in vivo studies, and preliminary toxicity profiling.

Despite recent progress in the fight against malaria, the emergence and spread of drug-resistant parasites remains a serious obstacle to the treatment of infections. We recently reported the development of a novel antimalarial drug that combines the 4-aminoquinoline pharmacophore of chloroquine with that of clotrimazole-based antimalarials. Here we describe the optimization of this class of hybrid drug through in-depth structure-activity relationship studies. Antiplasmodial properties and mode of action were characterized in vitro and in vivo, and interactions with the parasite's 'chloroquine resistance transporter' were investigated in a Xenopus laevis oocyte expression system. These tests indicated that piperazine derivatives 4b and 4d may be suitable for coadministration with chloroquine against chloroquine-resistant parasites. The potential for metabolism of the drugs by cytochrome P450 was determined in silico, and the lead compounds were tested for toxicity and mutagenicity. A preliminary pharmacokinetic analysis undertaken in mice indicated that compound 4b has an optimal half-life.

Design, synthesis, and antifungal activity of triazole and benzotriazole derivatives.

This study describes the design, synthesis and evaluation of a novel series of 1,2,4-triazole and benzotriazole derivatives as inhibitors of cytochrome P450 14alpha-demethylase (14DM). The chemical structures of the new compounds were confirmed by elemental and spectral ((1)H NMR, (13)C NMR, Mass) analyses. Compounds were designed by a generating virtual library of compounds and docking them into the enzyme active site. Furthermore, they were found to have in vitro activity against Microsporum canis, Trichophyton mentagrophyte, Trichophyton rubrum, Epidermophyton floccosum, and Candida albicans comparable to fluconazole and clotrimazole.

Flutrimazole shampoo 1% versus ketoconazole shampoo 2% in the treatment of pityriasis versicolor. A randomised double-blind comparative trial.

Flutrimazole is an imidazole derivative that has been proven to be efficient in superficial skin fungal infections. The aim of this randomised double-blind study was to compare for the first time, the efficiency and safety of flutrimazole 1% shampoo versus ketoconazole 2% shampoo in the treatment of tinea versicolor. Study population consisted of 60 patients with pityriasis versicolor diagnosed clinically and through direct microscopy and culture. Patients were randomly assigned to two groups: one instructed to apply flutrimazole shampoo 1% and one instructed to apply ketoconazole shampoo 2% both on head and body for 14 days. Patients were re-evaluated 14 days after the end of treatment clinically and through direct microscopy and culture. Twenty-one of 26 patients (80.8%) in the ketoconazole and 22 of 29 patients (75.9%) in the flutrimazole group had both visual healing and negative mycological evaluation. Comparison of the response between the two groups with the Yates' corrected chi-square was found statistically not significant (chi(2) = 0.19, d.f. = 1, P = 0.91). None of the patients in the two groups reported any adverse effects. Fourteen (53%) patients in the ketoconazole group and 23 (79%) in the flutrimazole group assessed the shampoos as cosmetically acceptable regarding texture, smell and foam properties. Flutrimazole shampoo 1% appears to present efficacy comparable with ketoconazole 2% in the treatment of tinea versicolor.

Genetic neural network modeling of the selective inhibition of the intermediate-conductance Ca2+ -activated K+ channel by some triarylmethanes using topological charge indexes descriptors.

Selective inhibition of the intermediate-conductance Ca(2+)-activated K(+ )channel (IK (Ca)) by some clotrimazole analogs has been successfully modeled using topological charge indexes (TCI) and genetic neural networks (GNNs). A neural network monitoring scheme evidenced a highly non-linear dependence between the IK (Ca) blocking activity and TCI descriptors. Suitable subsets of descriptors were selected by means of genetic algorithm. Bayesian regularization was implemented in the network training function with the aim of assuring good generalization qualities to the predictors. GNNs were able to yield a reliable predictor that explained about 97% data variance with good predictive ability. On the contrary, the best multivariate linear equation with descriptors selected by linear genetic search, only explained about 60%. In spite of when using the descriptors from the linear equations to train neural networks yielded higher fitted models, such networks were very unstable and had relative low predictive ability. However, the best GNN BRANN 2 had a Q ( 2 ) of LOO of cross-validation equal to 0.901 and at the same time exhibited outstanding stability when calculating 80 randomly constructed training/test sets partitions. Our model suggested that structural fragments of size three and seven have relevant influence on the inhibitory potency of the studied IK (Ca) channel blockers. Furthermore, inhibitors were well distributed regarding its activity levels in a Kohonen self-organizing map (KSOM) built using the inputs of the best neural network predictor.

The role of hydrogen bond acceptor groups in the interaction of substrates with Pdr5p, a major yeast drug transporter.

The yeast ABC (ATP-binding cassette protein) multidrug transporter Pdr5p transports a broad spectrum of xenobiotic compounds, including antifungal and antitumor agents. Previously, we demonstrated that substrate size is an important factor in substrate-transporter interaction and that Pdr5p has at least three substrate-binding sites. In this study, we use a combination of whole cell transport assays and photoaffinity labeling of Pdr5p with [(125)I]iodoarylazidoprazosin in purified plasma membrane vesicles to study the behavior of two series of novel substrates: trityl (triphenylmethyl) and carbazole derivatives. The results indicate that site 2, defined initially by tritylimidazole efflux, requires at least a single hydrogen bond acceptor group (electron pair donor). In contrast, complete inhibition of rhodamine 6G efflux and [(125)I]iodoarylazidoprazosin binding at site 1 requires substrates with three electronegative groups. Carbazole and trityl substrates with two groups show saturating, incomplete inhibition at this site. This type of inhibition is frequently observed in bacterial multidrug-binding proteins that use a pocket with multiple binding sites. The presence of multiple sites with different requirements for substrate-Pdr5p interaction may explain the broad specificity of xenobiotic compounds transported by this protein.

Percutaneous absorption and skin distribution of [14C]flutrimazole in mini-pigs.

The percutaneous absorption and skin distribution of a skin cream containing 1% 14C-labelled 1-[(fluorophenyl) (4-fluorophenyl) phenylmethyl]-1H-imidazole (flutrimazole, UR-4056, CAS 119006-77-8) was studied in minipigs. The same dose of flutrimazole was administered i.v. and topically (as a cream) on scarified skin according to a crossover protocol. Samples of urine and faeces were taken at various intervals after administration, and radioactivity was measured. The percentage of radioactivity accumulated in urine after topical and intravenous administration were 1.46% and 41.7%, respectively. In faeces, the percentage of radioactivity observed was 6.0% after intravenous administration, and none was detected after topical application. In order to study the distribution and penetration of [14C]flutrimazole, the cream was applied to intact and scarified skin. At various intervals after administration, skin samples were taken. The samples for the autoradiographic studies were cut transversely, and for the measurement of the levels of radioactivity at different skin depths, slices were cut parallel to the cutaneous layers. The results obtained indicate that [14C]flutrimazole penetrates quickly into the different epidermic layers and is retained mainly in the strata spinosum, granulosum and basale. The stratum basale possibly acts as a selective barrier preventing the penetration of the compound into the dermis. The percentage of radioactivity in the stratum corneum is lower than that detected in all the other epidermic layers taken together. The stratum corneum offers low resistance to penetration by the flutrimazole, which very probably crosses the epidermic strata by a transcellular route.

Local and systemic tolerance of flutrimazole skin creams following single and repeated topical application in healthy volunteers.

A double-blind, randomized phase I study was performed in 21 healthy volunteers to evaluate the dermal tolerance of skin creams containing 1% and 2% 1-[(2-fluorophenyl)(4-fluorophenyl)phenylmethyl]-1H-imidazole (flutrimazole, UR-4056, CAS 119006-77-8) or only the excipient, versus a commercial skin cream containing 1% clotrimazole. The study was carried out using the patch-test procedure performed in three stages: 1. single application in the back skin; 2. induction period (usage test) using three skin areas on the volar side of the forearm of each subject, where skin cream samples were applied once a day for a period of three weeks; and 3. after a wash-out period of two weeks, challenge applications in the back and forearm skin. The systemic tolerance of the formulations was also tested. There was no evidence of allergic sensitization after the application of flutrimazole creams, or their excipients, with signs of mild and doubtful skin reactions being observed in few subjects with all formulations. Furthermore, no systemic side effects after topical administration were detected throughout the study.

Toxicity studies with flutrimazole.

Studies with 1-[(2-fluorophenyl)(4-fluorophenyl)phenylmethyl]-1H- imidazole (flutrimazole, CAS 119006-77-8), a new topical imidazole antifungal agent, have been carried out to investigate the acute toxicity of the active substance in mice and rats, as well as the acute ocular and dermal irritation in rabbits, the dermal tolerance after repeated dose (21 days) applications in rabbits, and the sensitising, photoallergic and phototoxic potential in guinea pigs using 1% flutrimazole cream. LD50 values after oral or intraperitoneal administration were greater than or equal to 1000 mg/kg in both mice and rats, which reveal a very low acute toxicity of flutrimazole. No differences were found between the excipient and 1% flutrimazole cream in the acute ocular and dermal irritation studies in rabbits, the irritation indexes being indicative of no lesions due to flutrimazole. Cumulative dermal irritation studies in rabbits showed an improved local tolerance of a skin cream containing 1% flutrimazole as compared to a commercial skin cream containing 1% clotrimazole. The irritation indexes were 1.2 and 3.7, respectively (p less than 0.01). The corresponding histophatological findings confirmed the better local tolerance of 1% flutrimazole cream. Furthermore, it has been found that flutrimazole cream lacks sensitising potential (Magnusson and Kligman test), is also devoid of phototoxic potential and does not induce photoallergic reactions in guinea pigs, these data being confirmed by histopathological studies. These results, together with the very slight systemic absorption rate of flutrimazole from the 1% topical drug form, clearly show that no restrictions should be taken in the use of the cream for reasons of systemic toxicity or dermal tolerance.

Pharmacokinetic study of [14C]flutrimazole after oral and intravenous administration in dogs. Comparison with clotrimazole.

This trial involved a comparative study using 6 Beagle dogs on the pharmacokinetics of 14C-labelled 1-[(2-fluorophenyl)(4-fluorophenyl)phenylmethyl]-1H-imidazole (flutrimazole, CAS 119006-77-8) and [14C]clotrimazole labelled in the imidazole ring. On the basis of a cross-over trial, each animal received a dose of 5 mg/kg (approx. 100 microCi) [14C]flutrimazole and [14C]clotrimazole, both intravenously and orally. The levels in plasma, urine and faeces of the total radioactivity, unchanged drug and the [14C]imidazole formed by metabolization of the unchanged drug were determined. Flutrimazole presented a biological half-life (t1/2) of 14.4 +/- 3.8 h and a clearance (Cl) of 6.7 +/- 0.8 l/h, while the values for clotrimazole were very different: t1/2 4.6 +/- 0.8 h and Cl: 13.6 +/- 1.0 l/h. After oral administration a fraction of absorbed dose (f) of 78 +/- 21% and bioavailability of 8.9 +/- 6.1% were calculated for flutrimazole. For clotrimazole, these were: 52 +/- 10% and 4.9 +/- 1.9%, respectively. Both drugs showed a significant first-pass effect, with 90% of the absorbed dose being metabolized before reaching the systemic circulation. The total recovery of radioactivity in faeces and urine 5 days after i.v. and oral administration was 58% and 68%, respectively, for [14C]flutrimazole, and 81% and 79% for [14C]clotrimazole. In both cases, most of the radioactivity was recovered in the faeces. The high radioactivity obtained in faeces after i.v. administration of both drugs confirms biliary elimination. For both flutrimazole and clotrimazole, less than 1% of the total recovered in the urine after i.v. administration was recovered as unchanged drug.(ABSTRACT TRUNCATED AT 250 WORDS)