Evaluation of synergistic anticandidal activity of Galenia africana extract and fluconazole against Candida albicans and Candida glabrata

• Published in: Journal of herbal medicine 2022-03, Vol.32, p.100503, Article 100503
• Main Authors: Ng’uni, Tiza L., dos Santos Abrantes, Pedro Miguel, McArthur, Carole, Klaasen, Jeremy A., Fielding, Burtram C.
• Format: Article
• Language: English
• Subjects: Antifungal resistance; Broth microdilution; Candida species; Disk diffusion; Galenia africana; Susceptibility testing
• ISSN: 2210-8033
• DOI: 10.1016/j.hermed.2021.100503

[Display omitted] •Galenia africana exhibited anticandidal activity against the Candida species.•Synergistic interaction observed against C. albicans in the combination study.•Cell damage and decrease in cell size observed after G. africana treatment.•Cell damage potentially contributed to the synergistic interaction.•New information for the development of novel antifungal agents. Candida infections have increased in recent years and are causing a serious public health concern. In addition, Candida species are becoming resistant to numerous antifungal drugs. It is for this reason that alternative treatment options are being explored, using medicinal plants, to curb this trend of drug resistance. The aim of this study was to evaluate the anticandidal activity of an ethanolic extract of Galenia africana (G. africana) alone and particularly in combination with fluconazole (FLC) against Candida albicans and Candida glabrata. The anticandidal activity was evaluated using various techniques. The minimum inhibitory concentration (MIC) of the extract was 6.25 mg/mL for both Candida strains. A synergistic effect was observed when G. africana was combined with FLC, against C. albicans and an indifferent effect against C. glabrata when interpreted by the fractional inhibitory concentration index (FICI) (0.36 and 1.002 for C. albicans and C. glabrata, respectively). Microscopic analysis revealed cell damage and decrease in cell size after G. africana treatment. Collectively, these results suggest that G. africana possessed antifungal activity against the Candida strains and a synergistic effect with FLC. Cell damage observed possibly contributed to this synergistic effect. This provides new information for the development of new antifungal agents.