RESUMO
The present study describes the chemical composition, antifungal and antioxidant activity of Pelargonium graveolens essential oil. The essential oil profile was determined by GC and GC-MS. The main compounds were citronellol (24.54%), geraniol (15.33%), citronellyl formate (10.66%) and linalool (9.80%). Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) were recorded using the microdilution and macrodilution methods. Commercial antimycotic bifonazol was used as a control. The concentration of 0.25-2.5 mg/ml showed fungicidal activity. The most resistant fungi were Mucor mucedo and Aspergillus species. The antioxidant activity of pure essential oil was evaluated by means of the 2,2-diphenyl-1-picrylhydrazil (DPPH) radical assay. The essential oil of P. graveolens was able to reduce DPPH radicals into the natural DPPH-H form, and this activity was dose-dependent. The oil exhibited antioxidant activity and reduced DPPH to 50% at EC50 value of 0.802 mg/ml of oil solution.
RESUMO
BACKGROUND: Although standardized broth dilution methods for antifungal susceptibility testing are available, easier testing procedures are desirable. We evaluated the E-test (AB disk, Sweden) as a possible alternative instead of NCCLS (National Committee for Clinical Laboratory Standards) broth macrodilution method. METHODS: Fifty-two bloodstream isolates of Candida spp. (including 11 C. albicans, 13 C. tropicalis, 18 C. parapsilosis, 1 C. glabrata, 4 C. krusei, 2 C. pelliculosa, 2 C. lipolytica, and 1 C. guilliermondii) were tested. Amphotericin B and fluconazole MICs for each isolate were determined by both NCCLS broth macrodilution method and E-test. The results of E-test for Candida spp. were compared with those of NCCLS macrodilution method. For selecting plating media for E-test, we compared E-test results in two different media (RPMI and Casiton medium) using five ATCC Candida strains. RESULTS: As E-test media, we selected RPMI medium for amphotericin B and Casitone medium for fluconazole because of higher agreement with NCCLS method. The E-test and NCCLS method of 52 Candida spp. yielded a very narrow range of MICs (0.064-2.0 microgram/mL) for amphotericin B and a broad range of MICs (0.5-64 microgram/mL) for fluconazole. The agreements of E-test within one doubling dilutions of the macrodilution reference were 90.4% (24h and 48h) for amphotericin B, and 90.4% (24h) and 96.2% (48h) for fluconazole. CONCLUSION: The E-test is a valuable alternative to the NCCLS macrodilution method for amphotericin B and fluconazole susceptibility testing of Candida species.