Title:Antifungal Activity of Condensed Tannins from Stryphnodendron adstringens: Effect on Candida tropicalis Growth and Adhesion Properties
Volume: 17
Issue: 4
Author(s): Alexandre T. Morey, Felipe C. de Souza, Jussevania P. Santos, Caibe A. Pereira, Juscelio D. Cardoso, Ricardo S.C. de Almeida, Marco A. Costa, João C.P. de Mello, Celso V. Nakamura, Phileno Pinge-Filho, Lucy M. Yamauchi and Sueli F. Yamada-Ogatta
Affiliation:
Keywords:
Adhesion, Stryphnodendron adstringens, antifungal activity, biofilm, cell surface hydrophobicity, natural product,
Tenebrio molitor.
Abstract: Candida species are some of the most common causes of fungal infection worldwide. The limited efficacy of
clinically available antifungals warrants the search for new compounds for treating candidiasis. This study evaluated the
effect of condensed tannin-rich fraction (F2 fraction) of Stryphnodendron adstringens on in vitro and in vivo growth of
Candida tropicalis, and on yeast adhesion properties. F2 exhibited a fungistatic effect with the minimum inhibitory concentration
ranging from 0.5 to 8.0 μg/mL. A significant reduction in biofilm mass was observed after either pretreatment
of planktonic cells for 2 h (mean reduction of 46.31±8.17%) or incubation during biofilm formation (mean reduction of
28.44±13.38%) with 4x MIC of F2. Prior exposure of planktonic cells to this F2 concentration also significantly decreased
yeast adherence on HEp-2 cells (mean reduction of 43.13±14.29%), cell surface hydrophobicity (mean reduction of
25.89±10.49%) and mRNA levels of the genes ALST1-3 (2.9-, 1.8- and 1.8-fold decrease, respectively). Tenebrio molitor
larvae, which are susceptible to C. tropicalis infection, were used for in vivo testing. Treatment with 128 and 256 μg/mL
F2 significantly increased the survival of infected larvae. These results indicate a combined effect of F2 on inhibition of
yeast growth and interference in yeast adhesion, which may contribute to the suppression of infection caused by C. tropicalis,
thus reinforcing the potential of the condensed tannins from S. adstringens for the development of novel antifungal
agents.
