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Antifungal Effects (antifungal + effects)
Selected AbstractsAntifungal effects of herbal essential oils alone and in combination with ketoconazole against Trichophyton spp.JOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004S. Shin Abstract Aims:, To determine the effects of herbal essential oils on Trichophyton spp. growth and to evaluate the effects of Pelargonium graveolens oil and its main components citronellol and geraniol combined with ketoconazole against Trichophyton spp. Methods and Results:, Growth inhibition of six Trichophyton spp. by herbal essential oils was accessed and the combined effects of P. graveolens oil and its main components citronellol and geraniol were evaluated using a checkerboard microtitre assay against T. schoenleinii, T. erinacei and T. soudanense. The essential oil fraction of P. graveolens and its main components, geraniol and citronellol, exhibited strong synergism with ketoconazole against T. schoenleinii and T. soudanense, with fractional inhibitory concentration (FIC) indices in the range of 0·18,0·38. Conclusions:, The antifungal effects of ketoconazole against Trichophyton spp. are enhanced significantly by administering it in combination with the essential oil fraction of P. graveolens or its main components, because of strong synergism, especially against T. soudanense and T. schoenleinii. Significance and Impact of the Study:, The combination of ketoconazole and the essential oil fraction from P. graveolens or its main components for treatment of infections caused by Trichophyton species may reduce the minimum effective dose of ketoconazole, and thus minimize the side-effects of ketoconazole. [source] Antifungal effects of aminosulphoxide and disulphide derivativesMYCOSES, Issue 3 2006Veerle Wittebolle Summary 2-Benzenesulphinyl-(1,4)-naphtoquinone and 14 derivatives were synthesised and were used to evaluate their cytotoxicity against a human myelomonocyte cell line and their antifungal activity against two yeast, i.e. Candida albicans and C. tropicalis and against two filamentous fungi such as Aspergillus niger and Fusarium oxysporum and against one dermatophyte, namely Trichophyton tonsurans. The cytotoxicity and antifungal activities were investigated in comparison with amphotericin B as reference drug. No compound was significantly more toxic than amphotericin B at 0.2 ,g ml,1. The best results of antifungal activity were obtained with GFL 10, GFL 13 and GFL 30 on C. tropicalis, F. oxysporum and T. tonsurans. For C. albicans and A. niger, there was no difference between amphotericin B and the other molecules. The sterol quantitation, the time-kill curves were carried out for these three compounds in order to confirm their action in ergosterol synthesis. Time-kill curves showed a fungistatic activity. For C. tropicalis GFL 10, GFL 13 and GFL 30 increased the growth delay better than amphotericin B, in contrast to F. oxysporum. As for T. tonsurans, GFL10 and GFL13 gave a delay, but the effect of GFL 30 was a bit less marked. [source] High-dose methylprednisolone influences the physiology and virulence of Candida albicans ambiguously and enhances the candidacidal activity of the polyene antibiotic amphotericin B and the superoxide-generating agent menadioneFEMS YEAST RESEARCH, Issue 2 2007Ágnes Gyetvai Abstract Although exposure of Candida albicans cells to high-dose (4 mM) methylprednisolone stimulated microbial growth, germination rate in serum and phospholipase release, it also promoted the recognition of C. albicans cells by polymorphonuclear leukocytes. Pretreatment of C. albicans cells with methylprednisolone did not result in any increase in the pathogenicity of the fungus in intraperitoneal and intravenous mouse assays. Therefore, the virulence of C. albicans is unlikely to increase in patients treated with comparably high-dose methylprednisolone on skin and mucosal membranes. Methylprednisolone treatments also increased the production of conjugated dienes and thiobarbituric acid-reactive substances, and the menadione sensitivity of C. albicans cells, which can be explained by a significant decrease in the specific activities of several antioxidant enzymes. The combination of methylprednisolone with oxidants, e.g. in topical applications, may be of clinical importance when the predisposition to candidiasis is high. Methylprednisolone treatments negatively affected membrane fluidity and decreased the antifungal effects of both the polyene antibiotic nystatin and the ergosterol biosynthesis inhibitor lovastatin, and also enhanced the deleterious effects of the polyene antimycotic amphotericin B on C. albicans cells. These corticosteroid,polyene drug interactions should be considered in the treatment of C. albicans infections in patients with prolonged topical application of corticosteroids. [source] Penicillium chrysogenum glucose oxidase , a study on its antifungal effectsJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004É. Leiter Abstract Aims:, Purification and characterization of the high molecular mass Candida albicans -killing protein secreted by Penicillium chrysogenum. Methods and Results:, The protein was purified by a combination of ultrafiltration, chromatofocusing and gel filtration. Enzymological characteristics [relative molecular mass (Mr) = 155 000, subunit structure ,2 with Mr,, = 76 000, isoelectric point (pI) = 5·4] were determined using SDS-PAGE and 2D-electrophoresis. N-terminal amino acid sequencing and homology search demonstrated that the antifungal protein was the glucose oxidase (GOX) of the fungus. The enzyme was cytotoxic for a series of bacteria, yeasts and filamentous fungi. Vitamin C (1·0 mg ml,1) prevented oxidative cell injuries triggered by 0·004 U GOX in Emericella nidulans cultures but bovine liver catalase was ineffective even at a GOX : catalase activity ratio of 0·004 : 200 U. A secondary inhibition of growth in E. nidulans cultures by the oxygen-depleting GOX,catalase system was likely to replace the primary inhibition exerted by H2O2. Conclusions:,Penicillium chrysogenum GOX possesses similar enzymological features to those described earlier for other Penicillium GOXs. Its cytotoxicity was dependent on the inherent antioxidant potential of the test micro-organisms. Significance and Impact of the Study:,Penicillium chrysogenum GOX may find future applications in glucose biosensor production, the disinfection of medical implants or in the food industry as an antimicrobial and/or preservative agent. [source] In vitro antifungal activity of brassinin, camalexin and two isothiocyanates against the crucifer pathogens Alternaria brassicicola and Alternaria brassicaePLANT PATHOLOGY, Issue 2 2007A. Sellam In vitro assays investigated the responses of Alternaria brassicicola and A. brassicae isolates towards two crucifer phytoalexins and two isothiocyanates (ITC) by evaluating their potential toxic effects on different fungal growth parameters. Although variable responses towards each compound was observed within the species A. brassicicola, the results obtained confirmed the antifungal effects of camalexin, brassinin, allyl- (AlITC) and benzyl- (BzITC) isothiocyanates, at different developmental stages of both Alternaria species. Irrespective of the tested isolate, the phytoalexin camalexin exhibited the greater inhibitory effect with mean EC50 values ranging from 34 µm (germ-tube elongation) to 183 µm (mycelial growth). Germ-tube elongation was more sensitive compared to conidial germination and mycelial growth, with mean EC50 values of the former of 81 µm, 520 µm and 870 µm for brassinin, BzITC and AlITC, respectively. [source] Mechanisms involved in control of Blumeria graminis f.sp. hordei in barley treated with mycelial extracts from cultured fungiPLANT PATHOLOGY, Issue 5 2002H. Haugaard Treatment with mycelial extracts, prepared from liquid cultures of Bipolaris oryzae, Pythium ultimum and Rhizopus stolonifer, protected barley (Hordeum vulgare) against powdery mildew disease caused by the fungus Blumeria graminis f.sp. hordei. The mechanisms of this protection were studied using histopathological methods and molecular analysis. Germination and appressorial formation of B. graminis were generally reduced after treatment with mycelial extracts. Although this reduction (between 12 and 62% depending on treatment and experiment) was inconsistent and only occasionally significantly different from the water-treated control, it indicated a direct antifungal effect of the extracts. In situations where the fungus succeeded in forming an appressorium, penetration efficiency and haustorium formation from these appressoria was not affected , no enhanced penetration resistance associated with papilla formation was detected. However, a post-penetration effect was observed, as B. graminis colonies on mycelial extract-treated leaves produced 50% fewer hyphae than on controls. Northern blot analyses showed earlier accumulation of defence-related gene transcripts following treatment with B. oryzae and P. ultimum mycelial extracts, and to a lesser extent R. stolonifer mycelial extract, compared with water-treated leaves. It is suggested that the protection mechanism of the mycelial extracts involves direct antifungal effects and possible induced resistance for the B. oryzae and P. ultimum mycelial extracts. [source] | ||||||||||