Resumen:
BSTRACTContext: Biofilm formation is an important problem, since this growth mode confers resistance to drugsusually used in therapeutics.Objective: In vitro antifungal activity of extracts obtained from Heterophyllaea pustulata Hook f. (Rubiaceae)were studied against Candida tropicalis biofilms, evaluating the effect of irradiation and the oxidative andnitrosative stresses as possible mechanisms of action.Materials and methods: Hexane, benzene, ethyl acetate and ethanol extracts were evaluated at three concentrations(0.2, 0.1 and 0.05mg/mL) over mature biofilm, under darkness and irradiation. After 48 h ofincubation, biofilm quantitation was performed by the O?Toole and Kolter method. Reactive oxygen species(ROS) was measured by nitro-blue tetrazolium (NBT) reaction and reactive nitrogen intermediates (RNI) bythe Griess reagent. Superoxide dismutase activation (SOD, NBT assay) and total antioxidant system (FRAPtest) were studied.Results: Only the benzene extract at 0.2mg/mL reduced t