In vitro antifungal activities of medicinal plants used for treatment of candidiasis in Pader district, Northern Uganda

Abstract

Background The emergence of multidrug resistant Candida species to available drugs has led to renewed interest in the use of herbal medicines globally. This study scientifically verified antifungal effectiveness of five commonly used plant species in Pader district, against selected pathogenic candida strains. Methods Powdered roots of Momordica foetida, Sansevieria dawei and Distimake dissectus; and stem barks of Khaya anthotheca and Mitragyna rubrostipulata were extracted sequentially using petroleum ether and methanol, respectively; and total water extraction at 24.4 °C (maceration), 60 °C (decoction) and boiling water at 87 °C (hot water infusion). Extracts and their combinations, positive controls (amphotericin B, and fluconazole) and negative control (80% dimethyl sulfoxide, verified to be tolerable concentration to the tested Candida species) were screened and verified for their antifungal activity against Candida albicans (ATCC: American Type Culture Collection reference strain 10231, ATCC 90028, 0770a and 0796), C. glabrata (VVc 004, ATCC 2950) and C. tropicalis (ATCC 750 and 0210) using agar well diffusion and broth micro-dilution, respectively. Results Aqueous extract (24.4 °C) of M. rubrostipulata (ZOI: 18.00 ± 1.00 to 38.33 ± 0.17; MIC: 3.13 ± 0.00 to 20.83 ± 4.17; MFC: 12.50 ± 0.00 to 200.00 ± 0.00), methanol extract of K. anthotheca (10.11 ± 0.31 to 15.11 ± 0.65; 1.04 ± 0.26 to 12.50 ± 0.00; 12.50 ± 0.00 to 100.00 ± 0.00), and combination of aqueous extract (60 °C) of D. dissectus + methanol extract of K. anthotheca (7.89 ± 0.26 to 19.67 ± 0.37; 0.78 ± 0.00 to 50.00 ± 0.00; 12.50 ± 0.00 to 200.00 ± 0.00) exhibited broad spectrum antifungal activities and were fungistatic against all tested Candida species, which comprised 8 clinical/control and susceptible/resistant strains. None of the conventional drugs used demonstrated broad spectrum antifungal activity across all tested Candida species/strains. Conclusion Methanol extract of K. anthotheca, aqueous extract (24.4 °C) of M. rubrostipulata, and combination of aqueous extract (60 °C) of D. dissectus + methanol extract of K. anthotheca could be effective in the treatment of candidiasis. They demonstrated potential broad spectrum antifungal activity against different species and strains of tested Candida than the fluconazole and amphotericin B drugs. Their fungistatic nature showed their ability to inhibit fungal growth. Hence, these extracts/extract combination can offer better treatment option for candidiasis if they are standardized and also their active curative compounds isolated and made into antifungal drugs.