Data/hora: 07/06/2024 02:48:40

Provedor de dados: | 58
País: | Brazil
Título: | Chlorhexidine: beta-cyclodextrin inhibits yeast growth by extraction of ergosterol
Autores: | Teixeira,K. I. R.; Araújo,P. V.; Sinisterra,R. D.; Cortés,M. E.
Data: | 2012-06-01
Ano: | 2012
Palavras-chave: | Chlorhexidine; Β-cyclodextrin; Membrane-drug interactions.
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.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000200047
Editor: | Sociedade Brasileira de Microbiologia
Relação: | 10.1590/S1517-83822012000200047
Formato: | text/html
Fonte: | Brazilian Journal of Microbiology  v.43 n.2 2012
Fonte: | info:eu-repo/semantics/openAccess