Antifungal Properties of Crude Extracts, Fractions, and Purified Compounds from Bark of Curatella americana L. (Dilleniaceae) against Candida Species.
The ethnomedicinal plant Curatella americana L. (Dilleniaceae) is a common shrub in the Brazilian cerrado, in which crude extract showed antifungal activity in a preliminary study. In this work, the antifungal and cytotoxic properties of the crude extract, fractions, and isolated compounds from C. americana were evaluated against the standard yeast strains Candida albicans, C. tropicalis, and C. parapsilosis, clinical isolates, and fluconazole-resistant strains. The combinatory effects between subfractions and isolated compounds and effects on cell morphology, virulence factors, and exogenous ergosterol were also evaluated. The MIC obtained against the Candida species including fluconazole-resistant strain ranged from 15.3 to 31.3 µg/mL for crude extract, 3.9 to 15.6 µg/mL for ethyl acetate fraction, and 7.8 to 31.3 µg/mL for subfractions. The isolated compounds identified as 4'-O-methyl-catechin, epicatechin-3-O-gallate, and 4'-O-methyl-catechin-3-O-gallate showed lower antifungal activity than the crude extract and fractions (MIC ranging from 31.3 to 125.0 µg/mL). The addition of exogenous ergosterol to yeast culture did not interfere in the antifungal activity of the extract and its fractions. Synergistic antifungal activity was observed between subfractions and isolated compounds. The effects on virulence factors and the different mechanisms of action compared to fluconazole and nystatin suggest that this ethnomedicinal plant may be an effective alternative treatment for candidiasis.
Laboratory of Microbiology Applied to Natural and Synthetic Products, State University of Maringá, Colombo Avenue 5790, 87020-900 Maringá, PR, Brazil ; Faculty of Medicine and Pharmacy, Ingá College, Rodovia PR317, 6114, 87035-510 Maringá, PR, Brazil.
Cleyton Eduardo
CE
Mendes de Toledo
Laboratory of Microbiology Applied to Natural and Synthetic Products, State University of Maringá, Colombo Avenue 5790, 87020-900 Maringá, PR, Brazil.
Patrícia Regina
PR
Santos
Laboratory of Pharmacognosy-Palafito, State University of Maringá, Colombo Avenue 5790, 87020-900 Maringá, PR, Brazil.
João Carlos
JC
Palazzo de Mello
Laboratory of Microbiology Applied to Natural and Synthetic Products, State University of Maringá, Colombo Avenue 5790, 87020-900 Maringá, PR, Brazil.
Benedito Prado
BP
Dias Filho
Laboratory of Microbiology Applied to Natural and Synthetic Products, State University of Maringá, Colombo Avenue 5790, 87020-900 Maringá, PR, Brazil.
Celso Vataru
CV
Nakamura
Laboratory of Microbiology Applied to Natural and Synthetic Products, State University of Maringá, Colombo Avenue 5790, 87020-900 Maringá, PR, Brazil.
Tânia
T
Ueda-Nakamura