Banca de DEFESA: IVANILDO INÁCIO DA SILVA JÚNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : IVANILDO INÁCIO DA SILVA JÚNIOR
DATE: 27/02/2024
TIME: 10:00
LOCAL: Online via Google Meet
TITLE:

DEVELOPMENT OF NANOTECHNOLOGICAL PRODUCTS BASED ON ESSENTIAL OILS WITH ANTIMICROBIAL ACTION AGAINST MICROORGANISMS CAUSING BOVINE MASTITIS AND EVALUATION OF THEIR TOXICITY IN A ZEBRAFISH (Danio rerio) MODEL

KEY WORDS:

Embryogenesis; Phytotherapy; Nanoparticle; Staphylococcus aureus; Teratogenesis.

PAGES: 37
BIG AREA: Ciências Biológicas
AREA: Farmacologia
SUMMARY:

Milk plays an essential role in the Brazilian agribusiness economy. However, bovine mastitis, mainly caused by bacteria such as Staphylococcus aureus, poses a concern due to economic losses and challenges in control, especially because of antibiotic resistance. To address these challenges, the use of vegetable oils as a phytotherapeutic alternative has been explored, focusing on their antimicrobial efficacy. However, the direct application of these oils is limited, leading to the use of nanotechnological approaches to improve their bioavailability. This study evaluated the antimicrobial activity of essential oils, such as lemongrass, thyme, and oregano, against Staphylococcus aureus strains through agar disk diffusion testing, followed by the production and determination of the minimum inhibitory concentration (MIC) of chitosan nanoparticles containing these essential oils against S. aureus strains. Nine formulations were produced, three for each essential oil. The MIC was determined for both the essential oils and the produced nanoparticles (NPs). Lemongrass NPs (C1), thyme NPs (T3), and oregano NPs (O3) obtained MICs of 2,500 µg/mL, 1,250 µg/mL, and 156 µg/mL, respectively. Additionally, this study investigated the toxicity of these essential oils on zebrafish embryos and larvae. The results showed that all three essential oils caused a reduction in epiboly, indicating an impact on embryonic development. LC50 values were calculated for lemongrass (3.7 µg/mL), thyme (14.4 µg/mL), and oregano (5.3 µg/mL). Morphometric analysis revealed a reduction in the standard length of larvae at higher concentrations of all essential oils. Furthermore, exposure to essential oils resulted in alterations in the swimming behavior of zebrafish larvae during locomotor testing. These findings underscore the need for a cautious approach in the use of essential oils, especially during early developmental stages, raising concerns about the risks associated with excessive and unsupervised use of these compounds. However, they also reveal that nanotechnological products produced from essential oils can serve as a therapeutic alternative in combating diseases such as bovine mastitis, providing a phytotherapeutic approach that aligns with the global demand for reducing and replacing antibiotic use.

COMMITTEE MEMBERS:
Presidente - PABYTON GONCALVES CADENA
Interno - PAULO ROBERTO ELEUTERIO DE SOUZA
Externo ao Programa - 1929164 - FRANCISCO DE ASSIS LEITE SOUZA - UFRPEExterno à Instituição - EDUARDO PACHECO RICO - UNESC
Externo à Instituição - YURI MATEUS LIMA DE ALBUQUERQUE