Latest medical literature on oxistat

Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new oxistat research articles will be listed here shortly after becoming available to us.

Medical research on oxistat

Molecular properties of oxyconazole and tioconazole as the criteria for their bioavailability estimation.

Acta Pol Pharm. 2008 Jan-Feb; 65(1): 123-4
Grudzień M, Krakowiak N, Pluciński F, Mazurek AP
The use of hydration and solvatation free enthalpies (DeltaG(h), DeltaG(s)) as parameters describing water solubility and permeability of drugs was proved to be suitable quantities. The free enthalpies of hydration and solvation by water and chlorobenzene molecules at the Hartree-Fock (6-31G*) level applying PCM model were calculated for oxyconazole and tioconazole. The oxyconazole and tioconazole differ in water and chlorobenzene solubility, what is reflected in calculated DeltaG values and electrostatic potential. These characteristics discriminate both compounds with respect to water solubility and permeability. It may be concluded that the DeltaG values of hydration and solvation adequately reflect the water solubility and permeability of oxyconazole and tioconazole.

[In vitro comparison of antifungal activity of oxiconazole and econazole against yeast.]

Rev Iberoam Micol. 1998 Sep; 15(3): 118-24
Hamilton AJ, Gómez BL
Monoclonal antibodies (MoAbs) have had a major impact on many areas of biomedical research and almost since their advent have been used in the characterisation and identification of diagnostically important antigens of fungal pathogens. Their main significance lies in three, often inter-related areas: a) the definition and characterisation of antigens for use in detection of antibody responses, b) their direct use in the detection of diagnostically useful antigen in body fluids c) their application in immunohistochemical diagnosis. The degree to which MoAbs have been applied varies between fungal pathogens, and they have now been used, for example, in the serodiagnosis of Aspergillus spp., Cryptococcus neoformans, Histoplasma capsulatum and Paracoccidioides brasiliensis. Their use in producing diagnostic tests for other fungi such as Sporothrix schenckii and Penicillium marneffei has been more restricted but considerable potential exists for further development.

Imidazole antifungals, but not triazole antifungals, increase membrane Zn2+ permeability in rat thymocytes Possible contribution to their cytotoxicity.

Toxicology. 2008 Jun 27; 248(2-3): 142-50
Matsui H, Sakanashi Y, Oyama TM, Oyama Y, Yokota S, Ishida S, Okano Y, Oyama TB, Nishimura Y
The use of zinc as a nutritional supplement has become common in many countries. Since zinc has diverse actions, it may be difficult to predict its synergistic and/or antagonistic action in simultaneous presence of drug(s). The combination of imidazole antifungals, but not triazole antifungals, with 3-30 microM ZnCl2 significantly increased the lethality of rat thymocytes. Since intracellular Zn2+ exerts various actions on the process of cell death, there is a possibility that imidazole antifungals, but not triazole antifungals, increases concentration of intracellular Zn2+ ([Zn2+]i). To test the possibility, we examined the effects of imidazole and triazole antifungals on [Zn2+]i of rat thymocytes in absence and presence of extracellular Zn2+ by the use of FluoZin-3, a fluorescent Zn2+ indicator. Imidazole antifungals (clotrimazole, econazole, and oxiconazole) increased the [Zn2+]i in the presence of extracellular Zn2+ while it was not the case for triazole antifungals (itraconazole and fluoconazole). Thus, it is suggested that imidazole antifungals increase the membrane permeability of Zn2+. The potency order in the augmentation of FluoZin-3 fluorescence by imidazole antifungals in the presence of extracellular Zn2+ was the same as that in their cytotoxic action. Therefore, the cytotoxic action of imidazole antifungals may be related to their action on membrane Zn2+ permeability.

Tetrahydronaphthyl azole oxime ethers: The conformationally rigid analogues of oxiconazole as antibacterials.

Eur J Med Chem. 2008 Jan 25;
Bhandari K, Srinivas N, Shiva Keshava GB, Shukla PK
A series of novel (Z)- and (E)-2-imidazolo-/triazolo-methyl tetrahydronaphthyl oxime ethers (7-28) were synthesized as conformationally constrained analogues of oxiconazole and evaluated for antifungal and antibacterial activities. Many of these derivatives exhibited potent antibacterial activity and surprisingly none of them was active against fungal strains. The SAR studies showed that imidazole oxime ethers were more active than the corresponding triazole oxime ethers. Imidazole derivatives 8, 11, 12, 15, 18, 19, 21 and 23 exhibited high inhibitory activity with 1.56-0.39mug/mL MIC values against Klebsiella pneumoniae, Escherichia coli and Staphylococcus aureus. These compounds represent new structure scaffolds that can be further optimized to give new antibacterial agents with structures significantly different from those of existing classes of antibiotics.

Azole antimycotics differentially affect rifampicin-induced pregnane X receptor-mediated CYP3A4 gene expression.

Drug Metab Dispos. 2008 Feb; 36(2): 339-48
Svecova L, Vrzal R, Burysek L, Anzenbacherova E, Cerveny L, Grim J, Trejtnar F, Kunes J, Pour M, Staud F, Anzenbacher P, Dvorak Z, Pavek P
Azole antifungal drug ketoconazole has recently been demonstrated as an inhibitor of a ligand-induced pregnane X receptor (PXR)-mediated transcriptional regulation of the CYP3A4 gene through disruption of PXR interaction with steroid receptor coactivator (SRC)-1. In contrast, other clotrimazole-derived antifungal agents are known as potent inducers of CYP3A4 through PXR. In the present study, we examined effects of azole antimycotics clotrimazole, ketoconazole, econazole, oxiconazole, miconazole, fluconazole, and itraconazole on PXR-mediated expression of CYP3A4. We investigated individual effects of the tested azoles as well as their action on rifampicin-induced PXR-mediated transactivation and expression of CYP3A4 in LS174T cell line and primary human hepatocytes, their interactions with PXR ligand-binding domain, and azole-mediated recruitment of SRC-1 to PXR. In addition, applying the pharmacodynamic approach and dose-response analysis, we aimed to describe the nature of potential interactions of tested azole antimycotics coadministered with a prototypical PXR ligand rifampicin in transactivation of CYP3A4 gene. We describe additive and antagonistic interactions of partial and full agonists of PXR nuclear receptor in the therapeutic group of azole antimycotics in rifampicin-mediated transactivation of CYP3A4. We show that oxiconazole is a highly efficacious activator of CYP3A4 transactivation, which could be antagonized by rifampicin in a competitive manner. In addition, we show that activation of the CYP3A4 promoter is a complex process, which is not exclusively determined by azole-PXR interactions, and we suggest that the ability of some azoles to affect recruitment of SRC-1 to PXR modulates their net effects in transactivation of CYP3A4 both in the absence or presence of rifampicin.

[In vitro comparison of antifungal activity of oxiconazole and econazole against yeast.]

Rev Iberoam Micol. 1998 Jun; 15(2): 75-7
Pereiro MJ, Iglesias-Grobas A, Pérez JT
Oxiconazole was compared in vitro with econazole in tests with 400 yeasts strains. Tests were performed by measurement of growth inhibition by both microdilution in Sabouraud broth and a Shadomy' agar diffusion systems. The sensitivity/resistance percentages were similar in Candida albicans strains. Oxiconazole showed a higher activity than that of econazole in Candida spp. and yeasts other than Candida.

Combination of surgical avulsion and topical therapy for single nail onychomycosis: a randomized controlled trial.

Br J Dermatol. 2007 Aug; 157(2): 364-8
Grover C, Bansal S, Nanda S, Reddy BS, Kumar V
BACKGROUND: Conventional therapy of onychomycosis is prolonged and often frustrating, which is why combination therapy involving topical, oral and surgical measures has been advocated as the treatment of choice. There are no controlled studies evaluating the efficacy of nail avulsion followed by topical antifungal therapy. OBJECTIVES: To evaluate the efficacy of combined surgical and topical therapy for onychomycosis. METHODS: Forty patients with single nail onychomycosis [28 with distal and lateral subungual onychomycosis, seven with total dystrophic onychomycosis (TDO) and five with proximal subungual onychomycosis] were randomly assigned to four treatment groups. Each group received avulsion of the involved nail, followed by ketoconazole 2% cream without (group I) or with occlusion (group II), or oxiconazole 1% cream without (group III) or with occlusion (group IV). Topical therapies were applied twice daily. The patients were reviewed monthly and treatment was continued until the regrowth of completely normal nail (mycologically negative). In cured cases, further monthly review was carried out for at least 6 months, without any form of therapy. At each visit direct microscopic examination was repeated. RESULTS: There was a high dropout rate, with seven patients (group I), six patients (group II), six patients (group III) and eight patients (group IV) completing the treatment protocol. Out of these, mycological cure was achieved in three (43%) patients in group I, four (67%) in group II, two (33%) in group III and six (75%) in group IV. All the cases of TDO failed to respond to this therapy. Overall, 15 of 27 (56%) patients were cured with this approach. On further follow up, recurrence of onychomycosis was recorded in two patients in group I. No side-effects or long-term complications of the nail avulsion were encountered. Important limitations encountered in the present study included a small sample size, a high dropout rate (32%) and poor patient compliance. CONCLUSIONS: Contrary to earlier reports, surgical nail avulsion with topical antifungal agents was not found to be a very encouraging modality for the treatment of onychomycosis. Both oxiconazole and ketoconazole delivered comparable results. Occlusion improved the treatment outcome, although the difference was not statistically significant. As a subtype, TDO showed poorest response. Surgical nail avulsion followed by topical antifungal therapy cannot be generally recommended for the treatment of onychomycosis.

Oxime and oxime ether derivatives of 1,4-benzothiazine related to oxiconazole.

ChemMedChem. 2007 Aug; 2(8): 1208-13
Milanese L, Giacchè N, Schiaffella F, Vecchiarelli A, Macchiarulo A, Fringuelli R
The synthesis, in vitro antifungal activity, and molecular docking experiments of some oxime and oxime ether derivatives of azole 1,4-benzothiazine are reported herein, with the aim of evaluating the influence of a partially constrained scaffold that is structurally related to Oxiconazole and bearing the 1,4-benzothiazine moiety, on the inhibition of Candida albicans CYP51.

Species distribution and antifungal susceptibilities of dermatophytes during a one year period at a university hospital in Turkey.

Mycoses. 2007 Mar; 50(2): 125-9
Ozkutuk A, Ergon C, Yulug N
Dermatophyte infections have been considered to be a major public health problem in many parts of the world. The aim of this study was to determine the causative agents of dermatophytoses and their antifungal susceptibilities in a Turkish University Hospital, west of Turkey. A total of 926 patients suspected to have dermatophytic lesions were examined over a period of 1 year (2001-2002). Samples collected from skin, hair and nails were submitted to direct microscopical examination using KOH and Calcofluor white stain, cultured on Sabouraud dextrose agar and Mycosel agar. The prevalence of dermatophytoses was 7.34% (68/926). Trichophyton rubrum was the most frequent dermatophyte isolated (56%) followed by T. mentagrophytes (38%), T. violaceum (1.5%), T. verrucosum (1.5%), Microsporum canis (1.5%) and Epidermophyton floccosum (1.5%). Tinea pedis (47%) was the most common type of infection, followed by tinea unguium (29%), tinea inguinalis (15%), tinea corporis (7.4%) and tinea capitis (1.6%). Secondary, we have tested 68 strains of dermatophytes against four antifungal agents following mainly the National Committee for Clinical Laboratory Standards M38-P standard for filamentous fungi. In general, all antifungals were shown to be highly effective and itraconazole and naftifine appeared more active than ketoconazole and oxiconazole.

Identification of new human pregnane X receptor ligands among pesticides using a stable reporter cell system.

Toxicol Sci. 2006 Jun; 91(2): 501-9
Lemaire G, Mnif W, Pascussi JM, Pillon A, Rabenoelina F, Fenet H, Gomez E, Casellas C, Nicolas JC, Cavaillès V, Duchesne MJ, Balaguer P
Pregnane X receptor (PXR, NR1I2) is activated by various chemically unrelated compounds, including environmental pollutants and drugs. We proceeded here to in vitro screening of 28 pesticides with a new reporter system that detects human pregnane X receptor (hPXR) activators. The cell line was obtained by a two-step stable transfection of cervical cancer HeLa cells. The first transfected cell line, HG5LN, contained an integrated luciferase reporter gene under the control of a GAL4 yeast transcription factor-binding site. The second cell line HGPXR was derived from HG5LN and stably expressed hPXR ligand-binding domain fused to GAL4 DNA-binding domain (DBD). The HG5LN cells were used as a control to detect nonspecific activities. Pesticides from various chemical classes were demonstrated, for the first time, to be hPXR activators: (1) herbicides: pretilachlor, metolachlor, and alachlor chloracetanilides, oxadiazon oxiconazole, and isoproturon urea; (2) fungicides: bupirimate and fenarimol pyrimidines, propiconazole, fenbuconazole, prochloraz conazoles, and imazalil triazole; and (3) insecticides: toxaphene organochlorine, permethrin pyrethroid, fipronil pyrazole, and diflubenzuron urea. Pretilachlor, metolachlor, bupirimate, and oxadiazon had an affinity for hPXR equal to or greater than the positive control rifampicin. Some of the newly identified hPXR activators were also checked for their ability to induce cytochrome P450 3A4 expression in a primary culture of human hepatocytes. HGPXR, with HG5LN as a reference, was grafted onto nude mice to assess compound bioavailability through in vivo quantification of hPXR activation. Altogether, our data indicate that HGPXR cells are an efficient tool for identifying hPXR ligands and establishing pesticides as hPXR activators.