Antifungal activity of phenolic compounds identified in flowers from North Eastern Portugal against Candida species

Aim: To evaluate the antifungal effect of gallic acid, catechin, luteolin and quercetin, phenolic compounds identified from flowers of North Eastern Portugal, against Candida planktonic and biofilm cells. Materials & methods: The MICs were determined in Candida planktonic cells and the effect of phenolic compounds on Candida biofilms was assessed through quantification of colony-forming units. Results: MIC values demonstrated that gallic acid presented the highest effect against all Candida species. Catechin showed a similar effect against Candida albicans American Type Culture Collection (ATCC) 90028 cells. In addition, gallic acid and quercetin had demonstrated only a minimal effect against Candida species biofilms. Conclusion: Gallic acid affected the growth of the different planktonic Candida species in all concentrations used; still, catechin showed a similar effect against C. albicans ATCC 90028 and Candida glabrata ATCC 2001 cells. In addition, only gallic acid and quercetin demonstrated a slight effect against all Candida species biofilms.