Banca de DEFESA: NARA JULIANA SANTOS ARAUJO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : NARA JULIANA SANTOS ARAUJO
DATE: 05/12/2023
TIME: 14:00
LOCAL: Sala de Videoconferência da Faculdade de Medicina - UFCA (campus Barbalha)
TITLE:

Antibacterial potential and resistance reversal by Sarcomphalus joazeiro
(Mart.) Hauenschild extract and hecogenin acetate

KEY WORDS:

Saponin, Steroid Sapogenin, Efflux Pump, Biofilm, Infectious
Diseases, Natural Products.

PAGES: 133
BIG AREA: Ciências da Saúde
AREA: Saúde Coletiva
SUMMARY:

Bacterial resistance is an important public health problem, demanding the need for investment in
research in the pharmaceutical field in the search for alternatives to combat infectious diseases.
Natural products have increasingly gained prominence in this field due to the properties they
present. Among these, Sarcomphalus joazeiro has proven action in the treatment of diseases of
the respiratory and gastrointestinal tract and treatment of bacterial infections, due to the action of
secondary metabolites, such as saponins, which are substances made up of a lipophilic fraction

and a sapogenin, molecule that has antifungal, antibacterial, antiviral, anti-cancer and anti-
inflammatory activity. The present work evaluated the Antibacterial potential and reversal of

bacterial Resistance by Ethanolic Extract of Sarcomphalus joazeiro (Mart.) Hauenschild (EESJ)
and Hecogenin Acetate. An ethanolic extract of the bark was prepared and chemically
characterized using UPLC-ESI-QToF-MSE

. 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 activity modifying
the antibiotic action were carried out using the broth microdilution method. The 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 present significant antibacterial activity, with MIC ≥2048 μg/mL,
however, in combination with antibiotics, it potentiated the action of the drugs, promoting a
significant reduction in MIC as in the analysis against the S. epidermidis strain, where the MIC
of Gentamicin reduced from 16 μg/mL to 4 μg/mL, and had a relevant ability to inhibit biofilm
formation against bacterial strains, mainly against strains of S. aureus and P. aeruginosa. The
results for Hecogenin Acetate demonstrated the absence of 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
inhibiting the efflux pump, sapogenin did not show relevant activity, demonstrating an increase
in the MIC of norfloxacin against strains SA 11199-B and SA-K2068. In the evaluation of
antibiofilm capacity, it was observed that Hecogenin Acetate presented promising results for
both anti-formation activity and eradication activity. It was concluded that EESJ is mainly
composed of saponin derivatives and has important antimicrobial activity when associated with
conventional antibiotics, demonstrating enhancement of their action. It is also important to
highlight its ability to inhibit biofilm formation, especially S. aureus and Pseudomonas
aeruginosa strains. Hecogenin Acetate did not show intrinsic antimicrobial activity, however, it
showed a decrease in MIC when associated with antibiotics. In front of the efflux pumps, no
relevant reversal results were observed. Sapogenin has relevant antibiofilm activity.

COMMITTEE MEMBERS:
Interno - FRANCISCO NASCIMENTO PEREIRA JUNIOR
Externo à Instituição - HENRIQUE DOUGLAS MELO COUTINHO - URCA
Interno - IRI SANDRO PAMPOLHA LIMA
Presidente - JACQUELINE COSMO ANDRADE PINHEIRO