Abstract:
Antifungal activities of methanolic extracts of the leaves and fruits of some medicinal plants were evaluated by incorporating known volumes of the different extracts into molten Sabouraud Dextrose Agar (SDA) to make up for concentrations of 25 mg/ml, 50 mg/ml and 100 mg/ml respectively. Concentrations of 125 µg/ml, 250 µg/ml and 500 µg/ml of Miconazole were incorporated to serve as a positive control while 0.5 ml of DMSO served as a negative control. The plants extracts employed were from Azadirachta indica (Neem), Anacardium occidentale (Cashew), Euphorbia hirta (Asthma weed), Jatropha curcas (Physic nut), Acantus montanus (Mountain thistle) and Picralima nitida (òsúigwe in Igbo). A 2 mm agar disc cut out from the margin of actively growing cultures of each dermatophyte (Trichophyton soudanense, T.mentagrophytes, Cladosporium sp, T.rubrum and Fusarium sp) were inoculated on the agar plates containing varying concentrations of the different plant extracts, the standard antifungal agent and negative control in triplicates and incubated at 28 ºC. All the extracts exhibited antifungal activities of varying degrees with radial growth inhibitions (RGIs) ranging from 0-0.45 mm radius. Fifty percent (50 %) of the plants extracts comprising of Picralima nitida, Euphorbia hirta and Acantus montanus exhibited complete inhibition at 100 mg/ml against all the clinical isolates under investigation (p < 0.05) . Picralima nitida seed was the only plant extract with complete inhibition at 25 mg/ml against T.soudanense and T.rubrum. Picralima nitida was the closest in activity to miconazole. Azadirachta indica (Neem) was the only plant extract which did not exhibit complete inhibition against any of the clinical isolates at 100 mg/ml yet exhibited a significantly low RGI at the lowest concentration of 25 mg/ml better than others. Antifungal activities of the extracts against the clinical isolates were all found to be statistically significant with reference to miconazole.
