Banca de QUALIFICAÇÃO: NARA JULIANA SANTOS ARAUJO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : NARA JULIANA SANTOS ARAUJO
DATE: 22/09/2023
TIME: 14:00
LOCAL: Faculdade de Medicina - Campus Barbalha
TITLE:

ANTIBACTERIAL POTENTIAL AND REVERSAL OF BACTERIAL RESISTANCE OF Sarcomphalus EXTRACT joazeiro (Mart.) HAUENSCHILD AND ACETATE OF HECOGENIN

KEY WORDS:

Bacterial Resistance, Efflux Pump, Biofilm, Infectious Diseases, Natural Products

PAGES: 11
BIG AREA: Ciências da Saúde
AREA: Saúde Coletiva
SUMMARY:

Bacterial resistance is a phenomenon that has been consolidated as an important public
health problem, demanding the need for investment in research in the pharmaceutical
area in the search for alternatives to combat infectious diseases. Natural products have
gained more and more prominence in this field due to the properties they present.
Among the clinically relevant natural products, we mention Sarcomphalus joazeiro,
which has proven action in the treatment of respiratory tract diseases, gastrointestinal
system pathologies, treatment of bacterial infections and other illnesses. Such
characteristics are attributed to its secondary metabolites, such as saponins, which are
substances with emulsifying properties consisting of a lipophilic fraction and a
sapogenin, a molecule that has antifungal, antibacterial, antiviral, anticancer and antiinflammatory activity. The present work evaluated the antibacterial potential and
reversal of bacterial resistance of Ethanol Extract of Sarcomphalus joazeiro (Mart.)
Hauenschild (EESJ) and of Hecogenin Acetate. An ethanolic extract of the bark was
prepared and chemically characterized by UPLC-ESI-QToF-MSE. In order to carry out
microbiological tests, strains of Enterococcus faecalis, Staphylococcus epidermidis,
Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus
aureus and strains SA-1199, SA-1199B with overexpression of the NorA efflux pump
and SA-K2068 with overexpression of MepA pump for efflux pump inhibition assays
determined by subinhibitory concentration and in microdilution plates. The
determination of the minimum inhibitory concentration (MIC) and modifying activity of
the antibiotic action were performed using the broth microdilution method. Biofilm
assays were evaluated using the crystal violet method. The results of the chemical
characterization of EESJ showed the presence of 24 peaks of constituents, with the
majority presence of saponin derivatives. EESJ did not show significant antibacterial
activity, with MIC ≥2048 μg/mL, however, in combination with antibiotics, it
potentiated the action of drugs, promoting a significant MIC reduction as in the analysis
against the strain of S. epidermidis, where the MIC of gentamicin reduced from 16
μg/mL to 4 μg/mL, and relevant ability to inhibit biofilm formation against bacterial
strains, especially against strains of S. aureus and P. aeruginosa. The results for
Hecogenin Acetate showed no relevant antibacterial activity, however the association
with antibiotics reveals the decrease in MIC being more significant against the P.
Aeruginosa strain, where a reduction was observed in all antibiotics evaluated. In the
inhibition of the efflux pump, sapogenin did not show relevant activity, demonstrating
an increase in norfloxacin MIC against strains SA 11199-B and SA-K2068. It was
concluded that the EESJ is mainly composed of saponin derivatives and have important
antimicrobial activity when associated with conventional antibiotics, demonstrating
potentiation in their action. It is also important to highlight its ability to inhibit biofilm
formation, especially of the strain of S. aureus and Pseudomonas aeruginosa.
Hecogenin acetate did not show intrinsic antimicrobial activity, however, it showed a
decrease in MIC when associated with antibiotics. With the efflux pumps, no relevant
reversal results were observed.

BANKING MEMBERS:
Interno - FRANCISCO NASCIMENTO PEREIRA JUNIOR
Presidente - JACQUELINE COSMO ANDRADE PINHEIRO
Externa à Instituição - MARIA FLAVIANA BEZERRA MORAIS BRAGA - URCA