Banca de DEFESA: KAROLINA OLIVEIRA GOMES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : KAROLINA OLIVEIRA GOMES
DATE: 17/07/2024
TIME: 09:00
LOCAL: On line (Plataforma Teams)
TITLE:

Physical-chemical characterization and evaluation of the antimicrobial activity of green
propolis extracts from Apis mellifera and propolis extracts from stingless bees.

KEY WORDS:

Propolis; Antioxidants; Phenolic Compounds; Microbial Sensitivity Tests; Gram-Negative Bacteria; Gram-Positive Bacteria. 

PAGES: 153
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

The bioactive compounds present in propolis extracts confer antimicrobial and antioxidant properties to these products. Therefore, the aim of this study was to perform the physicochemical characterization and evaluate the antimicrobial activity of green propolis extracts from Apis mellifera and from stingless bees, including mandaçaia (Melipona quadrifasciata), jataí (Tetragonisca angustula), borá (Tetragona clavipes), and tubuna (Scaptotrigona bipunctata), produced in the Midwest and Southern regions of Brazil. For this purpose, 11 samples were obtained, comprising 9 commercial propolis extracts (green TB, A, PC, and PW, mandaçaia MM and MPC, jataí JPC, borá, and tubuna) and 2 samples of raw propolis (mandaçaia M and jataí J) which were prepared into extracts in the laboratory. Physicochemical analyses were determined by the content of dry extract, phenolic compounds, and antioxidant activity. The antibacterial activity was determined by disk diffusion assay, Minimum Inhibitory Concentration (MIC) determination, and Minimum Bactericidal Concentration (MBC). It was observed that 7 samples (63.63%) had a dry extract content above 11%, while 4 commercial samples (36.36%) had quantities below 11%, thus not complying with Brazilian legislation. All green propolis extracts showed phenolic compound values above 0.50%, complying with Brazilian legislation. Regarding the stingless bee samples, there was considerable variation in phenolic compound values (ranging from 0 to 2.66%). In Brazil, there is still no official regulation regarding minimum values of phenolic compounds and antioxidant activity for propolis extracts from stingless bees. The propolis extracts with the highest phenolic compound values also exhibited the highest antioxidant activity (green TB and borá), showing a positive correlation between the concentration of phenolic compounds and antioxidant activity. In the disk diffusion assay, the samples did not show inhibition zones against Gram-negative bacteria. For Gram-positive bacteria, 3 samples (27.27%) that were jataí (J and JPC) and tubuna did not exhibit inhibition zones, while the other 8 samples (72.73%) showed inhibition zones ranging from 19.0 to 49.0 mm. For Gram-positive bacteria, the MIC of the samples ranged from 0.001 to 0.20 mg/mL, and the MBC ranged from 0.02 to 0.50 mg/mL. The highest antimicrobial activities were obtained for green propolis extracts (TB, PW, A), and borá. The mandaçaia sample (M) also stood out for its efficient antimicrobial activity. For Gram-negative bacteria, the MIC of the propolis extracts ranged from 0.03 to 0.20 mg/mL, and the MBC ranged from 0.15 to 0.50 mg/mL. In this study, it became evident that very low levels of phenolic compounds and antioxidant activity impaired the antimicrobial activity of the propolis extracts from tubuna and jataí. Another noteworthy result was that the propolis extracts from the native bees mandaçaia (M) and borá exhibited antimicrobial activity comparable to that of green propolis extracts (TB, PW, and A), and these were the samples with the best antibacterial activities in the study.

COMMITTEE MEMBERS:
Externa à Instituição - CAINARA LINS DRAEGER - FACELS
Presidente - 1697332 - DANIELA CASTILHO ORSI
Externo ao Programa - 1880131 - GUILHERME MARTINS GELFUSO - UnBExterna à Instituição - VANIA SILVA CARVALHO - IFGOIANO