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Provedor de dados: |
BJM
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País: |
Brazil
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Título: |
Chlorhexidine: beta-cyclodextrin inhibits yeast growth by extraction of ergosterol
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Autores: |
Teixeira,K. I. R.
Araújo,P. V.
Sinisterra,R. D.
Cortés,M. E.
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Data: |
2012-06-01
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Ano: |
2012
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Palavras-chave: |
Chlorhexidine
Β-cyclodextrin
Membrane-drug interactions
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Resumo: |
Chlorhexidine (Cx) augmented with beta-cyclodextrin (β-cd) inclusion compounds, termed Cx:β-cd complexes, have been developed for use as antiseptic agents. The aim of this study was to examine the interactions of Cx:β-cd complexes, prepared at different molecular ratios, with sterol and yeast membranes. The Minimal Inhibitory Concentration (MIC) against the yeast Candida albicans (C.a.) was determined for each complex; the MICs were found to range from 0.5 to 2 µg/mL. To confirm the MIC data, quantitative analysis of viable cells was performed using trypan blue staining. Mechanistic characterization of the interactions that the Cx:β-cd complexes have with the yeast membrane and assessment of membrane morphology following exposure to Cx:β-cd complexes were performed using Sterol Quantification Method analysis (SQM) and scanning electron microscopy (SEM). SQM revealed that sterol extraction increased with increasing β-cd concentrations (1.71 × 10³; 1.4 × 10³; 3.45 × 10³, and 3.74 × 10³ CFU for 1:1, 1:2, 1:3, and 1:4, respectively), likely as a consequence of membrane ergosterol solubilization. SEM images demonstrated that cell membrane damage is a visible and significant mechanism that contributes to the antimicrobial effects of Cx:β-cd complexes. Cell disorganization increased significantly as the proportion of β-cyclodextrin present in the complex increased. Morphology of cells exposed to complexes with 1:3 and 1:4 molar ratios of Cx:β-cd were observed to have large aggregates mixed with yeast remains, representing more membrane disruption than that observed in cells treated with Cx alone. In conclusion, nanoaggregates of Cx:β-cd complexes block yeast growth via ergosterol extraction, permeabilizing the membrane by creating cluster-like structures within the cell membrane, possibly due to high amounts of hydrogen bonding.
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Tipo: |
Info:eu-repo/semantics/article
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Idioma: |
Inglês
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Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000200047
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Editor: |
Sociedade Brasileira de Microbiologia
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Relação: |
10.1590/S1517-83822012000200047
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Formato: |
text/html
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Fonte: |
Brazilian Journal of Microbiology v.43 n.2 2012
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Direitos: |
info:eu-repo/semantics/openAccess
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