Anticandidal activity of ten selected medicinal plants from Southern and North Central provinces of Sri Lanka
Candida is a commensal yeast which normally resides on the human body causing mild to serious infections and is the most frequent cause of fungal infections worldwide. Antifungals prescribed for the treatment of candidiasis have side effects and have become incompetent due to emerging resistance of fungi. Therefore, effective novel antifungals are required to overcome this obstacle. This study aimed to determine the anticandidal activity of selected medicinal plants used in ayurveda, against Candida albicans ATCC12420 and Candida glabrata ATCC 90030. Plants for the study were selected from Southern and North- Central provinces of Sri Lanka. Methanol extractions prepared from each plant were subjected to antifungal susceptibility testing (AFST) against both Candida species, according to the NCCLS guidelines. Fluconazole and dichloromethane were used as positive and negative controls respectively. The minimum fungicidal concentration (MFC) was determined for each plant extract by broth microdilution method. The initial concentration of 200 mg/mL of plant extract showed no clear zone of inhibition thus fungicidal activity could not be determined by disc diffusion method, however there was a reduced density of the lawn of growth with Citrus aurantiifolia, Cinnamomum verum, Phyllanthus emblica and Psidium guajava against C. glabrata and for C. verum against C. albicans. MFC was determined using doubling dilution of plant extracts with concentrations ranging from (500 mg/mL – 15.62mg/mL). A MFC of 31.25mg/mL for C. albicans were given by the plant extracts C. verum, C. longa and P. guajava. While a MFC of 31.25mg/mL was observed for C. glabrata with the plants extracts of S. grandiflora, C. verum, P. emblica and P. guajava. Leaf extracts of both C. verum and P. guajava have good antifungal activity against C. albicans and C. glabrata.