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Antifungal Properties of Crude Extracts, Fractions, and Purified Compounds from Bark of Curatella americana L. (Dilleniaceae) against Candida Species.

Mendes de Toledo CE, Santos PR, Palazzo de Mello JC, Dias Filho BP, Nakamura CV, Ueda-Nakamura T - Evid Based Complement Alternat Med (2015)

Bottom Line: The combinatory effects between subfractions and isolated compounds and effects on cell morphology, virulence factors, and exogenous ergosterol were also evaluated.The addition of exogenous ergosterol to yeast culture did not interfere in the antifungal activity of the extract and its fractions.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.

View Article: PubMed Central - PubMed

Affiliation: 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.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Effect of exogenous ergosterol (0–200 µg/mL) on the MIC of amphotericin B (◆), CE and subfraction F2#6 (▲), and subfraction F2#5 (×) against C. albicans.
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fig2: Effect of exogenous ergosterol (0–200 µg/mL) on the MIC of amphotericin B (◆), CE and subfraction F2#6 (▲), and subfraction F2#5 (×) against C. albicans.

Mentions: In evaluating the effect on ergosterol, the CE and F2 subfractions maintained their antifungal effects, even in the presence of different concentrations of ergosterol in the growth medium (Figure 2), suggesting that its mode of action is not the same as amphotericin B. Amphotericin B is a polyene that acts on the induction of membrane permeability to potassium, sodium, hydrogen, and nanoelectrolytes in the phospholipid bilayer and forms a complex with fungal ergosterol located in the membrane, resulting in the leakage of intracellular components and subsequent cell death [36]. Because of substrate competition, the increasing concentration of ergosterol in the medium is inversely proportional to its antifungal activity, meaning that the ergosterol concentration is essential for maintenance of the efficacy of amphotericin B. These results show that the extracts, fractions, and subfractions do not depend on ergosterol for their antifungal action, reinforcing the notion that they have a fungistatic effect.


Antifungal Properties of Crude Extracts, Fractions, and Purified Compounds from Bark of Curatella americana L. (Dilleniaceae) against Candida Species.

Mendes de Toledo CE, Santos PR, Palazzo de Mello JC, Dias Filho BP, Nakamura CV, Ueda-Nakamura T - Evid Based Complement Alternat Med (2015)

Effect of exogenous ergosterol (0–200 µg/mL) on the MIC of amphotericin B (◆), CE and subfraction F2#6 (▲), and subfraction F2#5 (×) against C. albicans.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4548135&req=5

fig2: Effect of exogenous ergosterol (0–200 µg/mL) on the MIC of amphotericin B (◆), CE and subfraction F2#6 (▲), and subfraction F2#5 (×) against C. albicans.
Mentions: In evaluating the effect on ergosterol, the CE and F2 subfractions maintained their antifungal effects, even in the presence of different concentrations of ergosterol in the growth medium (Figure 2), suggesting that its mode of action is not the same as amphotericin B. Amphotericin B is a polyene that acts on the induction of membrane permeability to potassium, sodium, hydrogen, and nanoelectrolytes in the phospholipid bilayer and forms a complex with fungal ergosterol located in the membrane, resulting in the leakage of intracellular components and subsequent cell death [36]. Because of substrate competition, the increasing concentration of ergosterol in the medium is inversely proportional to its antifungal activity, meaning that the ergosterol concentration is essential for maintenance of the efficacy of amphotericin B. These results show that the extracts, fractions, and subfractions do not depend on ergosterol for their antifungal action, reinforcing the notion that they have a fungistatic effect.

Bottom Line: The combinatory effects between subfractions and isolated compounds and effects on cell morphology, virulence factors, and exogenous ergosterol were also evaluated.The addition of exogenous ergosterol to yeast culture did not interfere in the antifungal activity of the extract and its fractions.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.

View Article: PubMed Central - PubMed

Affiliation: 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.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus