Synergistic Antifungal Activity of Magnoliae Cortex and Syzyii Flos against Candida albicans

Abstract

Candida albicans is a dermal fungus of the human body that is known to cause oral candidiasis, vaginal candidiasis, and bloodstream infections in immunocompromised people or in certain environmental conditions. As cases of strains resistant to antifungal agents in C. albicans have been reported, studies using plant materials as safe antifungal agents are being actively conducted. In this study, a total of 17 edible plant extracts showed antifungal activity against C. albicans as a result of evaluating a 280-plant extract library using paper disk diffusion method. Among them, the four extracts with the strongest antifungal activity (Cinnamomi Cortex, Cinnamomi Ramulus, Magnoliae Cortex, and Syzygii Flos) were selected and evaluated for synergistic antifungal activity against C. albicans. The combination of Magnoliae Cortex and Syzygii Flos showed a synergistic activity. The antifungal activity was evaluated based on the concentrations of magnolol and eugenol, the respective components of Magnoliae Cortex and Syzygii Flos. Magnolol and eugenol showed synergistic antifungal activities at the concentration ratio of 1:25 – 1:61. The antifungal activity of these two compounds contributes 28 to 48% to the synergistic antifungal activity of the combination of Magnoliae Cortex and Syzygii Flos extract. In this study, we propose that a combination of Magnoliae Cortex and Syzygii Flos can effectively inhibit the growth of C. albicans and that magnolol and eugenol are the responsible inhibitory compounds.