Presence Of Clotrimazole Research Articles

Colorimetric detection of clotrimazole environmental pollutant using a newly developed chemosensor; an experimental and theoretical study

ABSTRACT Clotrimazole (CTZ), as an antifungal medication, is used to treat dermatological infections in humans, and to remove fungal infections from plants in agriculture, but its widespread usage has led to pharmaceutical pollution and environmental concerns. In this study, a new bromopyrogallol red (BPR) and N i 2 + based colorimetric sensor was developed for the selective and sensitive detection of CTZ. The BPR-Ni complex showed a clear colour change from purple to violet in the presence of CTZ, and a significant change was observed in the UV-Vis spectrum. The stoichiometric ratio of 1:1 between BPR and N i 2 + was determined using the Benesi-Hildebrand method. DFT and time-dependent DFT (TD-DFT) were applied to identify the molecular and electronic structures of the BPR, BPR-Ni, and BPR-Ni-CTZ in ground and excited states. The nature of electronic excitations and charge transfers was evaluated using the natural transition orbitals (NTO). The NTO analysis reveals that the Ni atom facilitates the charge transfer process between BPR and CTZ and improves the sensitivity of the chemosensor. The quantum theory of atoms in molecules (QTAIM) was employed to determine the nature of interactions between BPR, N i 2 + , and CTZ. This study paves the way for the detection of environmentally harmful pharmaceutical pollution using simple but effective colorimetric sensors.

Delayed clearance of the pro-carcinogen benzo[a]pyrene in PLHC-1 cells when co-exposed to the antifungal drug clotrimazole and effects on the CYP1A biomarker

Cytochrome P450 1 A (CYP1A) is a key enzyme in the metabolism of the polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BaP) in animals, and a biomarker for environmental PAH exposure. The common antimycotic imidazole drug clotrimazole (CLO) has been detected in the aquatic environment and likely co-exists with BaP. Like BaP, CLO can bind to CYP1A enzymes and can act as a CYP1A inhibitor. Co-exposure of BaP with CLO significantly delayed BaP elimination in a fish liver cell line (PLHC-1). Intracellular BaP concentration was 2.4 times higher after 6 h in co-exposed cells, compared to cells exposed to BaP alone. Higher BaP concentrations in cells co-exposed to CLO positively correlated with CLO dose, indicating CLO-mediated delays in BaP clearance. After 24 h, BaP was undetectable irrespective of CLO co-exposure. In contrast, intracellular CLO concentrations remained constant over the 72 h experimental period. Co-exposure of BaP with CLO caused synergistic and time-dependent increases on the CYP1A biomarker both on CYP1A mRNA levels and on CYP1A enzyme activity, in accordance with an apparent delayed BaP elimination in the presence of CLO. These results indicate a toxicokinetic interaction between BaP and CLO on the CYP1A enzyme that delays metabolic clearance of BaP.

Clotrimazole Fluidizes Phospholipid Membranes and Localizes at the Hydrophobic Part near the Polar Part of the Membrane.

Clotrimazole (1-[(2-chlorophenyl)-diphenylmethyl]-imidazole) is an azole antifungal drug belonging to the imidazole subclass that is widely used in pharmacology and that can be incorporated in membranes. We studied its interaction with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) phospholipid vesicles by using differential scanning calorimetry and found that the transition temperature decreases progressively as the concentration of clotrimazole increases. However, the temperature of completion of the transition remained constant despite the increase of clotrimazole concentration, suggesting the formation of fluid immiscibility. 1H-NMR and 1H NOESY MAS-NMR were employed to investigate the location of clotrimazole in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) phospholipid membranes. In the presence of clotrimazole, all the resonances originating from POPC were shifted upfield, but mainly those corresponding to C2 and C3 of the fatty acyl, chains suggesting that clotrimazole aromatic rings preferentially locate near these carbons. In the same way, 2D-NOESY measurements showed that the highest cross-relaxation rates between protons of clotrimazole and POPC were with those bound to the C2 and C3 carbons of the fatty acyl chains. Molecular dynamics simulations indicated that clotrimazole is located near the top of the hydrocarbon-chain phase, with the nitrogen atoms of the imidazole ring of clotrimazole being closest to the polar group of the carbonyl moiety. These results are in close agreement with the NMR and the conclusion is that clotrimazole is located near the water–lipid interface and in the upper part of the hydrophobic bilayer.

Corrosion inhibition of zinc in 0.1 M hydrochloric acid medium with clotrimazole: Experimental, theoretical and quantum studies

Clotrimazole an antifungal drug was investigated for its corrosion inhibition action on zinc metal in 0.1 M HCl solution. Corrosion rate was determined by weight loss, potentiodynamic polarization and impedance spectroscopic techniques. Electrochemical methods (EIS and polarization) have reported inhibition efficiency of up to 90% for 500 ppm concentration of clotrimazole. Data obtained from both chemical and electrochemical studies showed that the corrosion rate of Zn decreased with increase in inhibitor concentration and also with temperature. Tafel polarization measurements showed that clotrimazole acts as mixed type of corrosion inhibitor and its adsorption on the zinc surface obeys Langmuir isotherm. Thermodynamic activation and quantum chemical parameters were calculated and discussed to describe the mechanism of adsorption. These results were supported by FTIR spectral study of corrosion product formed on the zinc surface in the presence of clotrimazole. Contact angle measurements show increased hydrophobicity of zinc surface, while SEM images of zinc surface confirmed considerable decrease of surface inhomogenities in the presence of clotrimazole.

Synergistic Anti-Candida Activity of Bengazole A in the Presence of Bengamide A †.

Bengazoles A–G from the marine sponge Jaspis sp. exhibit potent in vitro antifungal activity against Candida spp. and other pathogenic fungi. The mechanism of action (MOA) of bengazole A was explored in Candida albicans under both liquid culture and surface culture on Mueller-Hinton agar. Pronounced dose-dependent synergistic antifungal activity was observed with bengazole A in the presence of bengamide A, which is also a natural product from Jaspis sp. The MOA of bengazole A was further explored by monitoring the sterol composition of C. albicans in the presence of sub-lethal concentrations of bengazole A. The GCMS of solvent extracts prepared from liquid cultures of C. albicans in the presence of clotrimazole―a clinically approved azole antifungal drug that suppresses ergosterol biosynthesis by the inhibition of 14α-demethylase―showed reduced cellular ergosterol content and increased concentrations of lanosterol and 24-methylenedihydrolanosterol (a shunt metabolite of ergosterol biosynthesis). No change in relative sterol composition was observed when C. albicans was cultured with bengazole A. These results eliminate an azole-like MOA for the bengazoles, and suggest that another as-yet unidentified mechanism is operative.

Clotrimazole, but not dexamethasone, is a potent in vitro inhibitor of cytochrome P450 isoforms CYP1A and CYP3A in rainbow trout

The effects of clotrimazole (CLO) and dexamethasone (DEX), both detected in the aquatic environment, were assessed on inhibition of cytochrome P450 (CYP450) in hepatic microsomes of rainbow trout. Activity of three CYP450 isoforms: ethoxyresorufin O-deethylase (EROD; CYP1A), 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase (BFCOD; CYP3A) and p-nitrophenol hydroxylase (PNPH; CYP2E1-like protein) was investigated in the presence of four concentrations of CLO and DEX. Clotrimazole in a concentration range of 1–100μM decreased the activity of EROD and BFCOD. The inhibition was reversible, as pre-incubation of the microsomes with CLO, before addition of the substrate, had no effect. EROD activity was non-competitively inhibited with a Ki of 0.5μM, and BFCOD activity revealed competitive inhibition with a Ki of 0.04μM. The relatively low Ki for CLO inhibition of EROD and BFCOD activity may indicate that the ability of CYP1A and CYP3A to metabolize xenobiotics is reduced in the presence of CLO. PNPH activity was not affected by CLO. DEX showed no inhibitory potency on any investigated reaction. CLO, but not DEX, inhibited EROD and BFCOD activity by different mechanisms.

Sublingual Tacrolimus: A Pharmacokinetic Evaluation Pilot Study

To evaluate and compare the pharmacokinetic parameters of sublingual and oral tacrolimus in the presence and absence of a drug that interacts with tacrolimus at the intestinal level. Prospective, randomized, open-label, parallel-group pilot study. Large, urban, academic medical center. Six adults with end-stage renal disease who were awaiting kidney transplantation; five completed the study. Patients were randomized in a 1:1 ratio to receive tacrolimus plus a clotrimazole troche (a drug that interacts with tacrolimus at the intestinal level) or tacrolimus plus nystatin suspension. For the tacrolimus route of administration, patients first received sublingual tacrolimus for five doses; after a 2-day washout period, they received oral tacrolimus for five doses. Demographic characteristics, concomitant medications, tacrolimus dosing information, and steady-state venous whole blood specimen values after tacrolimus administration were collected. Noncompartmental pharmacokinetics were calculated from the tacrolimus blood concentrations in samples collected at multiple time points after drug administration. The area under the concentration-time curve from 0-6 hours for sublingual and oral tacrolimus ranged from 27.2-66 and 32.4-76mg·hour/L, respectively, in the tacrolimus plus clotrimazole group and from 9.3-63 and 4.9-23.2mg·hour/L, respectively, in the tacrolimus plus nystatin group. The average maximum concentration was higher during sublingual administration than during oral administration: 16.7 versus 12.9ng/ml in the tacrolimus plus clotrimazole group and 9.5 versus 6ng/ml in the tacrolimus plus nystatin group. An oral-to-sublingual tacrolimus dose conversion should be evaluated on an individual basis. A 1:1 dose conversion may be appropriate in the presence of clotrimazole, whereas a 2:1 oral-to-sublingual conversion may be appropriate when there are no concomitantly interacting drugs. These findings should be investigated further in pharmacokinetic studies conducted in solid organ transplant recipients.

Analysis, fate studies and monitoring of the antifungal agent clotrimazole in the aquatic environment

The analysis and presence of clotrimazole, an antifungal agent with logK(OW) > 4, was thoroughly studied in the aquatic environment. For that reason analytical methods based on gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry were developed and validated to quantify clotrimazole with limits of quantification down to 5 and 1 ng/L, respectively. Both methods were compared in an intercalibration exercise. The complete mass-spectrometric fragmentation pattern could be elucidated with the aid of quadrupole time of flight mass spectrometry. Since clotrimazole tends to adsorb to laboratory glassware, studies on its adsorption behaviour were made to ensure the appropriate handling of water samples, e.g. pH, storage time, pretreatment of sampling vessels or material of the vials used for final extracts. The phenomena of adsorption to suspended matter were investigated while analysing different waste-water samples. Application of the methods in various investigated wastewater and surface water samples demonstrated that clotrimazole could only be detected in the low nanogram per litre range of anthropogenic influenced unfiltered water samples after acidification to pH 2.

Stimulation of erythrocyte phosphatidylserine exposure by lead ions

Pb+ intoxication causes anemia that is partially due to a decreased life span of circulating erythrocytes. As shown recently, a Ca(2+)-sensitive erythrocyte scramblase is activated by osmotic shock, oxidative stress, and/or energy depletion, leading to exposure of phosphatidylserine at the erythrocyte surface. Because macrophages are equipped with phosphatidylserine receptors, they bind, engulf, and degrade phosphatidylserine-exposing cells. The present experiments were performed to explore whether Pb+ ions trigger phosphatidylserine exposure of erythrocytes. The phosphatidylserine exposure was estimated on the basis of annexin binding as determined using fluorescence-activated cell sorting (FACS) analysis. Exposure to Pb+ ions [> or =0.1 microM Pb(NO3)2] significantly increased annexin binding. This effect was paralleled by erythrocyte shrinkage, which was apparent on the basis of the decrease in forward scatter in FACS analysis. The effect of Pb+ ions on cell volume was virtually abolished, and the effect of Pb+ ions on annexin binding was blunted after increase of extracellular K+ concentration. Moreover, both effects of Pb+ ions were partially prevented in the presence of clotrimazole (10 microM), an inhibitor of the Ca(2+)-sensitive K+ channels in the erythrocyte cell membrane. Whole cell patch-clamp experiments disclosed a significant activation of a K(+)-selective conductance after Pb+ ion exposure, an effect requiring higher (10 microM) concentrations, however. In conclusion, Pb+ ions activate erythrocyte K+ channels, leading to erythrocyte shrinkage, and also activate the erythrocyte scramblase, leading to phosphatidylserine exposure. The effect could well contribute to the reported decreased life span of circulating erythrocytes during Pb+ intoxication.

Clotrimazole inhibits lung fibroblast proliferation in vitro: implications for use in the prevention and treatment of obliterative bronchiolitis after lung transplantation.

Immunosuppressive therapy has limited activity against the mesenchymal cell proliferation of obliterative bronchiolitis. Clotrimazole (CLT) has been shown to inhibit proliferation in normal and cancer cell lines. Here we investigate whether CLT inhibits the proliferation of lung mesenchymal cells. Proliferation of human lung fibroblasts (MRC-5) in the presence of CLT was determined by [3H]thymidine incorporation. Messenger ribonucleic acid (mRNA) expression of platelet-derived growth factor (PDGF)-B and transforming growth factor (TGF)-beta after treatment with CLT was measured by reverse transcriptase-polymerase chain reaction. Treatment of MRC-5 cells with CLT resulted in a significant reduction in proliferation as assessed by DNA incorporation and cell counts compared with dimethylsulfoxide alone. There was no cytotoxic effect associated with CLT treatment. Reverse transcriptase-polymerase chain reaction demonstrated a marked decrease in PDGF-B and TGF-beta mRNA levels in cells treated with CLT compared with those treated with dimethylsulfoxide. CLT inhibits proliferation of human lung fibroblasts. This inhibitory effect is associated with decreased levels of PDGF-B and TGF-beta mRNA expression and may have value in the prevention and treatment of obliterative bronchiolitis.

Cytochrome P-450 inhibition blocks bone resorption in vitro and in vivo

Although the cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism have been shown to lead to osteoclastic resorption, the cytochrome P450 pathway has not been implicated. We investigated the effects of the cytochrome P450 pathway in IL-1β–induced calcium release from cultured mouse calvaria in vitro in the presence of clotrimazole, a cytochrome P450 inhibitor, or l -N G -arginine methyl ester, a nitric oxide synthase inhibitor. Clotrimazole inhibited calcium release in a dose-dependent manner; however, l -N G -arginine methyl ester did not inhibit resorption. These results suggest that cytochrome P450 may be another possible mediator of IL-1β–induced bone resorption in vitro. In the in vivo portion of the study, clotrimazole was administered in the gerbil model of adaptive bone modeling. Clotrimazole inhibited osteoclast surface; however, it did not reduce the osteoclast number, mean erosion surface per osteoclast, mineralization surface, or mineral-apposition rate. These results suggest that clotrimazole may inhibit the activation of osteoclasts and that cytochrome P450–dependent enzymes may be related to osteoclast activation in vivo. (Otolaryngol Head Neck Surg 1999;120:84-91.)

INTERACTION BETWEEN FK506 AND CLOTRIMAZOLE IN A LIVER TRANSPLANT RECIPIENT

FK506, a new and powerful immunosuppressant, has become the principal drug in the immunosuppressive regimens of organ transplant recipients at the University of Pittsburgh (1–3). It is well known that transplant patients often receive multiple-drug therapy, and that many of these co-administered agents can alter the kinetics of immunosuppressive drugs, such as cyclosporine and prednisone (4,5). In this communication we report for the first time a potential interaction between FK506 and the antifungal agent clotrimazole in a liver transplant recipient.

In vitro susceptibility of Trichophyton mentagrophytes arthroconidia to clotrimazole and griseofulvin in human corneocyte suspensions

The use of corneocytes in suspension as a medium for the study of the effect of antifungal drugs on Trichophyton mentagrophytes arthroconidia was investigated. In the presence of clotrimazole or griseofulvin, arthroconidia germination in a suspension of corneocytes and in Sabouraud glucose liquid medium was significantly reduced compared with germination in drug-free media. Where antifungals were added to arthroconidia after an activation period during which germination occurred, any further germination was inhibited. The data showed that the growth of T. mentagrophytes in the presence of corneocytes offered a simple, rapid, inexpensive and relevant model for the assessment of antifungal activity of compounds for the treatment of dermatophytosis.