A study of plants used to manage candida infections in Tanzania

Abstract

Candidiasis is one of the major opportunistic infections in individuals living with HIV infection especially those with severe immunosupression. The control of candidiasis is faced with several problems including, the limited number of effective drugs, the slow rate at which new drugs are being developed, the side effects and cost associated with these drugs. Furthermore relapse of candidiasis and resistance of Candida species to commonly used drugs are other important impeding factors in the management of candidiasis. These difficulties associated with the management of Candida infections necessitate the development of new anti-fungal agents in order to widen the spectrum of activities against Candida and combat strains expressing resistance to the available anti- fungal agents. In view of the above facts, this study was carried out on 56 plantsspecies collected from four regions in the Eastern part of Tanzania namely Coast, Dar es Salaam, Morogoro and Tanga. The specific objectives ofthe study were; (i) to screen plants growing in Tanzania for anticandida activity, (ii) to isolate the compounds active against Candida, (iii) to elucidate their structures and (iv) to determine their minimum inhibitory concentrations (MICs). A total of 63 aqueous methanolic extracts, prepared from 56 plant species collected based on 'interviews with traditional healers and literature search were screened against Candida albicans standard strain ATCC 90028 using bioautography agar overlay method. Twenty-eight out of the 63 plant extracts, belonging to 27 plant species and constituting 48% of all the plants collected were found to be active. Furthermore twenty (55.5%) out of 36 plants, obtained through interviewing traditional healers, were found active. Albizia anthelmintica root bark and Combretum zeyheri leaves were given priority for detailed chemical investigation and isolation of bioactive compounds. Albizia anthelmintica which was collected from two traditional healers, had not been previously evaluated for antifungal activity and became the most active of all plants screened. Combretum zeyheri was collected based on literature reports that it was active on several Candida species in three different countries in Africa and in this study it showed two