195 - Isoquercitrin, a phytochemical derived from Aster yomena, improves convetional antibiotics affect through reactive oxygen species accumulation in Candida albicans

Abstract

Isoquercitrin, one of phytochemical isolated from aerial parts of Aster yomena, has been reported to has antifungal activity. However, the synergistic effect and mechanism of isoquercitrin in combination with conventional antifungal agents are poorly understood. Therefore, synergistic antifungal effect between isoquercitrin and conventional antifungal agents were investigated. The interaction between isoquercitrin and antifungal agents was evaluated using checkerboard assay. Combinations of isoquercitrin with amphotericin B and fluconazole showed synergistic interaction against Candida albicans but combination with flucytosine showed no interaction. This synergism was shown to induce intracellular reactive oxygen species (ROS) accumulation and oxidative stress. To determine whether synergy-induced ROS affect cells, N-acetylcysteine (NAC) was used. Accumulated ROS caused membrane damage and apoptosis. In summary, isoquercitrin exhibited synergistic antifungal effect with antifungal agents through ROS accumulation. The synergistic effect between isoquercitrin and antifungal agents suggests the combinations of these compounds are a potential antifungal agent.