Banca de DEFESA: JOAO HENRIQUE DE OLIVEIRA REIS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JOAO HENRIQUE DE OLIVEIRA REIS
DATE: 03/12/2021
TIME: 09:00
LOCAL: Plataforma Conferencia Web - RNP
TITLE:

Chemical and biological characterization of red propolis extracts from Northeast Brazil search for different extraction methods

KEY WORDS:

Red propolis, supercritical fluid extraction, ultrasound, geographic origin, cytotoxicity, antioxidant activity.

 

PAGES: 98
BIG AREA: Outra
AREA: Tecnologia e Inovação
SUMMARY:

Introduction: Propolis is a natural compound of wide application in the food, pharmaceutical and cosmetic areas, being a complex resin produced by bees through the mixture of exudates from different plants, wax and salivary secretions. Variations in the chemical composition, and consequently, in the biological activity of propolis extracts, are associated with many factors. Objective: In this study, the influence of the extraction method and geographic origin on the composition of red propolis extracts obtained by conventional (ethanolic) and ultrasound-assisted extraction were evaluated, as well as the process conditions for obtaining extracts using the supercritical fluid extraction (SFE). Methodology: Initially, conventional (ethanolic) and ultrasound-assisted extraction methods were used to extract active propolis compounds from different regions of Northeast Brazil (Sergipe, Alagoas, Bahia, and Rio Grande do Norte). Contents of phenolic compounds, flavonoids, in vitro antioxidant activity, concentration of markers (formononetin and kaempferol) and cytotoxicity to human tumor cell lines (HCT116 - human colon, HL60 - leukemia, PC3 – carcinoma of the prostate and SNB19 – glioblastoma) were determined and comparatively evaluated for the twelve extracts obtained from six different samples. Additionally, red propolis extracts were obtained by SFE from a sample from Alagoas using different process conditions. To determine the process parameters applying SFE, were studied and obtained the Global Extraction Curves (OEC), S/F (mass of CO₂/mass of propolis), percentage of co-solvent (ethanol - 0, 1, 2 and 4%) and the global yield isotherms (GYI - Global Yield Isotherms) as a function of different pressures (250, 350 and 450 bar) and temperatures (31.7, 40 and 50°C). The total phenolic compounds, antioxidant activity and the content of formononetin, naringenin and kaempferol in the extracts obtained under different conditions used (SFE) were investigated. Results: As a result of this study, significant variations were identified (p>0.05) in the content of the compounds investigated in red propolis extracts, confirming that the chemical composition varies according to the region where the samples were collected. The highest concentration of the compounds of interest and the highest in vitro antioxidant activity were shown by extracts obtained from samples from the state of Alagoas (A1, A2, B1 and B2), which is currently the only one in Brazil that has a certificate of origin. Formononetin and kaempferol were identified in all samples. The highest concentrations of formononetin were identified in the extracts obtained by ultrasound, indicating a greater selectivity for the extraction of this compound by this method. Regarding the cytotoxic activity, for the HCT-116 strain, all extracts showed inhibition greater than 90%, while for the HL-60 and PC3 strains the lowest identified inhibition was 80%. In general, there was no significant difference (p>0.05) in antiproliferative potential when comparing extraction methods. The results showed that the composition of Brazilian red propolis varies significantly depending on the geographic origin and that the method used influences the resulting compounds that are present in the propolis. Regarding to the application of SFE as an extractive method, within the parameters investigated, the best conditions found were an S/F of 131 and the use of ethanol at the highest concentration (4%), which resulted in higher extract yields and higher content of antioxidant compounds. Formononetin, the main biomarker of red propolis, was the compound found in the highest amounts in extracts obtained by SFE under all conditions used. As expected, the temperature and pressure conditions also influenced the process yield, with 350 bar and 40°C being the best conditions for obtaining bioactive compounds from a red propolis sample. Conclusion: The new results for red propolis found in this study show that it is possible to obtain extracts with high antioxidant potential using alternative technologies, as well as that the geographical origin, the type of method used and the process conditions influence the quality of the extract obtained.

BANKING MEMBERS:
Externo à Instituição - ALEX ALISSON BANDEIRA SANTOS - Senai
Externo à Instituição - ANIBAL DE FREITAS SANTOS JUNIOR - UNEB
Externa ao Programa - 4725209 - CAROLINA OLIVEIRA DE SOUZA
Externo à Instituição - JEANCARLO PEREIRA DOS ANJOS - Senai
Presidente - 287294 - LUZIMAR GONZAGA FERNANDEZ