Inhibitive effect on phagocytosis of Candida albicans induced by pretreatment with quercetin via actin cytoskeleton interference

ObjectiveTo investigate the anti-inflammatory effect of pretreatment with quercetin on macrophages after Candida albicans infection.MethodsRAW 264.7 macrophages were used as a target cell line. Cell viability after treatment with quercetin at different time points was detected by Carboxyfluorescein diacetate, succinimidyl ester. Phagocytic function of macrophages was determined by a fluorometric assay. Cytokine tumor necrosis factor α (TNF-α) production was measured by enzyme-linked immunosorbent assay. F-actin cytoskeleton of L929 cells was stained by Alexa Fluor® 488-phalloidin.ResultsPretreatment with quercetin decreased cell viability only at the highest concentration of 37 µg/mL 2, 24, and 48 h after the treatment. The phagocytic efficiency of macrophages pretreated with quercetin was significantly decreased in a time- and dose-dependent manner. F-actin labeling showed that the actin cytoskeleton of the cells started to break down 2 h after treatment. Moreover, it notably inhibited cytokine TNF-α production after Candida albicans infection.ConclusionPretreatment with quercetin induced an anti-inflammatory effect against Candida albicans infection in macrophages.