Enhanced antifungal activity of ketoconazole by Euphorbia characias latex against Candida albicans

The in vitro suseptibility of Candida albicans to ketoconazole and Euphorbi a characias latex alone or in combination was tested using the macrobroth d ilution method. The MIC 80% of crude latex and ketoconazole are respectivel y 159 mug protein/ml and 0.3901 mug/ml. This method permits us to determine an affinity constant K-aff for crude latex (0.015 mug(-1) protein ml) and ketoconazole (23.828 mug(-1) ml). The utilization of a mixture of latex at several concentrations (7.8-15.62-31.25-62.5 and 125 tg protein/ml) and ket oconazole indicates a synergistic effect between latex and ketoconazole. Fo r latex concentrations of 31.25 and 62.5 mug protein/ml the MIC 80% of keto conazole were inferior (0.194 and 0.183 mug/ml respectively) to that obtain ed with ketoconazole alone (0.390 mug/ml). A synergistic effect is therefor e obtained between ketoconazole on the one hand and two concentrations of E uphorbia characias latex. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.