In vitro inhibition of Candida albicans growth by plant extracts and essential oils

Abstract

The opportunistic Candida albicans yeast strain ATCC 10261 grows at 37 °C and gives germ tubes after 3 h on corn meal agar and blood plasma. It produces chlamydospores and assimilates sucrose, dextrose, galactose, maltose, trehalose and xylose among the tested carbon sources. Other growth characters were also investigated. The agar diffusion cut plug technique revealed that 200 μl of Foeniculum vulgare Miller (fennel), Mentha piperita L. (peppermint) and Citrus limon (lemon) essential oils showed inhibitory actions. Fumigation test of the three essential oils had complete inhibition on the growth. The essential oil of Eucalyptus occidentalis End1 (eucalyptus, eucalypt) had no influence on C. albicans growth by the two tests. Meanwhile, methanol extracts of both leaves and male cones of the conifer Thuja orientalis (eastern thuya) had an inhibitory influence on the growth by two tests (cut plug and filter paper disc assay). In comparative tests the antibiotics mycostatin and dermatin had an inhibitory activity on C. albicans at the concentrations of 50–80 μg per hole. Crude methanol extract of leaves of eastern thuya (10–80 μg/ml) reduced C. albicans growth and intercellular protein nitrogen on liquid media.