Banca de QUALIFICAÇÃO: LUANDA BARBARA FERREIRA CANARIO DE SOUZA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LUANDA BARBARA FERREIRA CANARIO DE SOUZA
DATA : 26/03/2019
HORA: 09:00
LOCAL: SALA 1 DO PPGCF
TÍTULO:

Influence of Eugenia uniflora Extract onAdhesionto Human Buccal Epithelial Cells, Biofilm Formation, and Cell Surface Hydrophobicity of Candida spp. from the Oral Cavity of Kidney Transplant Recipients

PALAVRAS-CHAVES:

Candida spp., oral candidiasis, kidney transplant recipients, virulence factors, Eugenia uniflora, mechanism of action

PÁGINAS: 76
GRANDE ÁREA: Ciências da Saúde
ÁREA: Farmácia
RESUMO:

Candidiasis is an important oral manifestation in renal transplant patients. Candida spp. have virulence factors that contribute to the infectious process, including the ability to adhere to epithelial cells and biofilm formation on biotic and abiotic surfaces. The extract obtained from the leaves of Eugenia uniflora [acetone:water (7:3, v/v)] has demonstrated antifungal activity against Candida spp. This study evaluated the influence of E. uniflora extract on human oral epithelial cell adhesion (HBEC), biofilm formation and cell surface hydrophobicity, as well as elucidation of the mechanism of action of this extract in Candida spp strains isolated from the oral cavity of renal transplant patients. For virulence assays evaluated in vitro, yeasts were cultured in the presence and absence of 1000 μg/mL extract. In the adhesion assay a ratio of 10:1 cells (Candida spp. X HBECs cells) was incubated for 1 hour at 37°C, 200 rpm, fixed with 10% formalin and the number of Candida cells adhered to 150 CEBH were determined under an optical microscope. The biofilms were formed in polystyrene microplates in the presence and absence of the extract. Quantification was carried out using two methodologies: with violet crystal staining and XTT (2,3-bis (2-methoxy-4-nitro-5-sulfophenyl) -2H-tetrazolium-5-carboxanilide), and then analyzed by electron microscopy of scanning. CSH was determined by the hydrocarbon adhesion test. In silico assays were performed to verify the antifungal activity of the most important compounds of E. uniflora extract. Tests such as the exogenous ergosterol binding and sorbitol osmoprotection assay were performed to evaluate the action of the extract at the membrane and fungal cell walls. We observed that the extract of E. uniflora was able to reduce the adhesion of HBECs and CSH in strains of Candida albicans and non-Candida albicans species. We verified a statistically significant reduction in the ability to form biofilm by the biofilm producing strains by both quantification methodologies employed. In the in silico assays, gallic acid, the second majoritary compound in the extract, showed antifungal activity, binding to the CPY51 enzyme present in the fungal cell, which could be one of the possible mechanisms of action of the extract, interfering with ergosterol biosynthesis. The extract discreetly increased MIC when the ergosterol binding assay was performed, ruling out direct binding of the extract to that molecule. In the presence of sorbitol, the MIC values for the extract were increased, suggesting that one of the possible mechanisms of action of E. uniflora extract is to act on the fungal cell wall. This study reinforces the idea that, in addition to inhibition of growth, E. uniflora may interfere with the expression of some virulence factors of Candida spp., and may be eventually applied as a possible antifungal agent in the future.

MEMBROS DA BANCA:
Interno - 1893445 - EUZEBIO GUIMARAES BARBOSA
Externo ao Programa - 2195251 - HUGO ALEXANDRE DE OLIVEIRA ROCHA
Presidente - 1490222 - SILVANA MARIA ZUCOLOTTO LANGASSNER