The antioxidant activity of a prenyl flavonoid alters its antifungal toxicity on Candida albicans biofilms

PERALTA MARIANA; ORTEGA MARIA GABRIELA ; CABRERA J.L; PARAJE MG

FOOD AND CHEMICAL TOXICOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2018

0278-6915

The antioxidant effect of 8PP, a prenylflavonoid from Dalea elegans on Candidaalbicans biofilms, was investigated. We previously reported that sensitive (SCa) and resistant C. albicans (RCa) biofilms were strongly inhibited by this compound, in a dosedepending manner (50 µM-100 µM), with a prooxidant effect leading to accumulation of endogenous oxidative metabolites and increased antioxidant defenses. In this work, the antifungal activity of high concentrations of 8PP (200-1000 µM), the cellular stress imbalance and the architecture of biofilms were evaluated. Biofilms were studied by crystalviolet and confocal scanning laser microscopy (CSLM) with COMSTAT analysis.Superoxide anion radical, the activity of the superoxide dismutase and the total antioxidant capacity were measured. Intracellular ROS were detected by a DCFH-DA and visualized by CSLM; reactive nitrogen intermediates by Griess.An antioxidant effect was detected at 1000 µM and levels of oxidant metabolitesremained low, with major changes in the SCa. COMSTAT analysis showed that biofilms treated with higher concentrations exhibited different diffusion distances with altered topographic surface architectures, voids, channels and pores that could change the flow inside the matrix of biofilms. We demonstrate for first time, a concentration-dependent antioxidant action of 8PP, which can alter its antifungal activity on biofilms.