Ethnobotanical Survey, Bioactivity and Safety of Medicinal Plants used in the Management of Candidiasis in Pader District, Northern Uganda

Abstract

Background: The emergence of resistant Candida species to most conventional drugs has led to resurgence in herbal usage. Objectives: This study documented anti-candida plants in Pader district, assessed their antifungal activities and safety. Methods: Ethnobotanical data of potential anti-candida plants was collected using questionnaires among 63 herbalists identified by snowball technique. Four focus group discussions (FGDs) were used to ascertain community’s perceptions on the use of anti-candida plants using interview guide. Roots/ stem barks of five priority anti-candida plants: Sansevieria dawei Stapf, Momordica foetida Schumach., Distimake dissectus (Jacq.) A. R. Simões & Staples, Khaya anthotheca (Welw.) C.DC. and Mitragyna rubrostipulata (K.Schum.) Havil. were collected and extracted using petroleum ether, methanol and total water extraction. Agar well diffusion and broth micro dilution methods were respectively used to screen and verify antifungal activity of these plants against resistant and susceptible strains of Candida albicans, Candida glabrata and Candida tropicalis. Toxicity assessment of methanolic stem bark extracts of K. anthotheca was done according to OECD guidelines 425 and 407 for acute and sub-acute toxicity evaluation respectively. Results: Thirty-two plant species were documented for treatment of candidiasis. Five priority plants were Momordica foetida (26), Sansevieria dawei (20), Khaya anthotheca (15), Mitragyna rubrostipulata (05) and Distimake dissectus (05), of which, the aqueous extract at 24.4 oC of M. rubrostipulata (ZOI: 18.00±1.00 - 38.33±0.17; MIC: 3.13±0.00 - 20.83±4.17), methanol extract of K. anthotheca (10.11±0.31 -15.11±0.65; 1.04±0.26-12.50±0.00), and combination of aqueous extract at 60 oC of D. dissectus + methanol extract of K. anthotheca (7.89±0.26 - 19.67±0.37; 0.78±0.00- 50.00±0.00) exhibited activity against all tested Candida species, unlike the positive controls that cleared only some. Generally, the methanolic stem bark extract of K. anthotheca was safe at LD50 ˃ 5000mg/kg b.w, and was well tolerated at 125mg/kg b.w at sub-acute. However, higher subacute doses of 250 and 500 mg/kg b.w were toxic to the liver and stomach. Conclusion: Thirty two plants used by Pader communities against candidiasis were documented. Methanol extract of K. anthotheca, aqueous extract at 24.4 oC of M. rubrostipulata, and combination of aqueous extract at 60 oC of D. dissectus + methanol extract of K. anthotheca demonstrated activity against all Candida species tested. The most efficacious plant, K. anthotheca was generally safe at acute (LD50 ˃ 5000mg/kg body weight) and subacute (125mg/kg of body weight) toxicity tests. However, the long term treatment with higher extract doses above 250 mg/kg was toxic to the liver and stomach. Thus, long term administration of the extract at high doses should be done with cautions of the likely side effects.