Antifungal bioactivity of selected medicinal plants used in treatment of fungal infections in the Lake Victoria Basin, Kenya

Abstract

Opportunistic fungal infections are common in immunocompromised patients especially those with HIV/AIDS. The Lake Victoria Basin has some of the highest prevalence rates of HIV/AIDS hence high prevalence of these fungal infections. At least 10% of HIV/AIDS patients die of opportunistic fungal infections. Various herbs/herbal preparations claimed to treat fungal infections were collected and tested for their antifungal activity. Out of 25 samples collected, six plants were selected for bioactivity analysis based on preliminary results. Extractions were done using hot water, cold water and organic solvents Dichloromethane (CH2CL2)/Methanol (MeOH) in the ratio 1:1. Antifungal activity was tested on a yeast fungus, Candida albicans and a filamentous fungus, Aspergillus niger using disc diffusion technique. Dichloromethane and Methanol (1:1) extracts of Toddalia asiatica (root), Rhamnus staddo (root) , Momordica foetida (shoot), Podocarpus falcatus (bark), Aloe sp (secculent leaves), Gladiolus dalenii (bulb) showed activity against one or both of the test organisms. P. falcatus showed the highest activity (77.77% mean inhibition) against A.niger while M. foetida showed the highest activity (77.78% mean inhibition) against C. albicans. G. dalenii extracts inhibited spore production in A. niger up to day 5. Commercially used antifungal drugs, Ketaconazole and Griseofulvin (Cosmos Pharmaceuticals) were used as standards. Compounds responsible for the activity were identified using silica gel Thin Layer Chromatography (TLC) and appropriate spraying agents. Alkaloids and flavanoids were the major antifungal components reported. Results of this study indicate the possibility of developing plant-based drugs, from ethnomedicinal surveys, to help in longterm management of Aspergillosis and Candidiasis, which are the frequent complications encountered in HIV-AIDS patients.