2-methoxycinnamaldehyde and Candidiasis

This work evaluates the antifungal activity of two essential oil components against 28 clinical isolates (17 sensitive, 11 resistant) and 3 standard laboratory strains of Candida. Growth of the organisms was significantly effected in both solid and liquid media at different test compound concentrations. The minimum inhibitory concentrations (MICs) of Isoeugenol (compound 1) against 31 strains of Candida ranged 100-250 μg/ml and those of o -methoxy cinnamaldehyde (compound 2) ranged 200-500 μg/ml, respectively. Insight studies to mechanism suggested that these compounds exert antifungal activity by targeting H(+)-ATPase located in the membranes of pathogenic Candida species. At their respective MIC(90) average inhibition of H(+)-efflux for standard, clinical and resistant isolates caused by compound 1 and compound 2 was 70%, 74%, 82% and 42%, 42% and 43%. Respective inhibition of H(+)-efflux by fluconazole (5 μg/ml) was 94%, 92% and 10%. Inhibition of H(+)-ATPase leads to intracellular acidification and cell death. SEM analysis of Candida cells showed cell membrane breakage and alterations in morphology. Haemolytic activity on human erythrocytes was studied to exclude the possibility of further associated cytotoxicity.

Topics: Acrolein; Antifungal Agents; Candida; Candidiasis; Erythrocytes; Eugenol; Humans; Microbial Sensitivity Tests; Oils, Volatile; Proton-Translocating ATPases

The antifungal activity of the essential oil from Cinnamomum cassia, alone or combined with amphotericin B, a drug widely used for most indications despite side-effects was investigated. The composition of the oil was analysed by GC/MS and characterized by its very high content of cinnamaldehyde (92.2%). The minimal inhibitory concentration (MIC 80%), used to evaluate the antifungal activity against Candida albicans, was determined by a macrobroth dilution method followed by a modelling of fungal growth. The essential oil of Cinnamomum cassia exhibited strong antifungal effect (MIC 80% = 0.169 microL/mL and K(aff) = 18,544 microL/mL). A decrease of the MIC 80% of amphotericin B was obtained when the culture medium contained essential oil concentrations ranging from 0.08 to 0.1 microL/mL. The strongest decrease (70%) was obtained when the medium contained 0.1 microL/mL of essential oil. This potentiation of amphotericin B obtained in vitro may show promise for the development of less toxic and more effective therapies especially for the treatment of HIV infection.

Topics: Acrolein; Amphotericin B; Antifungal Agents; Candida albicans; Candidiasis; Cinnamates; Cinnamomum aromaticum; Drug Synergism; Gas Chromatography-Mass Spectrometry; Microbial Sensitivity Tests; Oils, Volatile; Phytotherapy; Plant Extracts; Regression Analysis