Screening of traditionally used South African plants for antifungal activity against Candida albicans

Abstract

Twenty-four South African medicinal plants were screened against Candida albicans standard strain ATCC 10231 and two clinical isolates from a 5-month-old baby and an adult, in an attempt to find a traditional remedy to treat oral candidiasis, which is prevalent in HIV-patients. Allium sativum L. and Tulbaghia violacea L. aqueous bulb extracts had MIC values of 0.56 and 3.25mg/ml respectively, whilst Polygala myrtifolia L. leaves and Glycyrrhiza glabra L. rhizome extracts had MIC values of 1.56 mg/ml when tested against the 5-month-old isolate. Fresh water extracts stored at 4, 23 and 33 degrees C over a period of a week, were used to determine the stability of these extracts. Allium sativum and Tulbaghia violacea maintained activity at 4 degrees C, but not at higher temperatures, whereas Polygala myrtifolia and Glycyrrhiza glabra lost activity within a day even at 4 degrees C. The unpleasant taste of the two species with a garlic smell, could however not be masked, and as the smell following the eating of the two species would lead to HIV-patients being recognised, these two plants where not considered for further investigation. Therefore, Polygala myrtifolia and Glycyrrhiza glabra are being further investigated for use as an oral mouthwash in clinics and homes.