Banca de DEFESA: RENAN FELIPE SILVA SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RENAN FELIPE SILVA SANTOS
DATE: 28/02/2023
TIME: 14:30
LOCAL: Remota
TITLE:

Evaluation of the antifungal activity of melaleuca leucadendron hydroalcoholic extract (MYRTACEAE) under Malassezia sp strains, causing dermatitis and otitis in dogs. 

KEY WORDS:

Dogs, Dermatopathies, Malassezia pachydermatis, Phytotherapy, Medicinal Plants.

PAGES: 63
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUBÁREA: Clínica e Cirurgia Animal
SPECIALTY: Clínica Veterinária
SUMMARY:

Malasseziosis is a disease caused by yeasts of the genus Malassezia, causing otological diseases and dermatopathies in humans and animals, being the species Malassezia pachydermatis more involved in animals. Treatment occurs with the use of azole antifungals topically or systemically. However, Malassezia already has resistance to this group of drugs, besides that azole drugs can cause toxicity reactions. The use of medicinal plants and herbal products are then presented as an alternative to conventional treatment because it presents fewer reactions to the use, and low resistance factor. Being an important area of research for new antibiotic and antifungal therapies. Thus, Melaleuca leucadendron, a plant of Australian origin, presents levels of secondary metabolites that justify its antiseptic action to various agents, such as bacteria of the genus Staphylococcus sp., Streptococcus sp. and pseudomonas, as well as fungi such as Candida sp. However, this plant is still little studied for other fungal groups. Therefore, the objective of this work is to evaluate the antifungal action of this plant for Malassezia sp strains. Samples were collected from the plant to confirm the species collected and production of a hydroalcoholic extract by the cold percological method. For this, the leaves of the plant were dried in a circulating air kiln at 40ºC for 24 hours, macerated and added 700 ml of PA alcohol and 300 ml of distilled water, being left at rest for 15 days and evaporated the solvent in a rotational evaporator. Subsequently, qualitative phytochemical analyses were performed in order to verify the presence of the following secondary metabolites: terpenes, quinones, saponins, flavonoids, phenols and alkaloids. For the fungal sensitivity test, malassezia samples were collected from animals clinically affected with dermatitis and otitis. Initially, a gare diffusion disc mycological test was performed with 10 samples and a new analysis was performed with 6 more samples by the broth microdilution method. At the end of the experiments it was verified by phytochemical analyses that the extract had the presence of phenols, terpenes, flavonoids and quinones, indicators that the extract has antiseptic and healing action. However, in both mycological tests the extract does not have an expected antifungal action, and the non-appearance of the inhibition halo in all samples and in the microdilution test was verified in all wells. It may be related to the fungal resistance factors of malassezia, its biofilm production or even differences in the concentration of secondary metabolites in the extract produced. It was concluded that although the hydroalcoholic extract of M. leucadendron does not present antifungal action for Malassezia sp. this action cannot be ruled out for other fungal species. In addition to the need for quantitative phytochemical studies to quantify the concentration of metabolites and the subtypes present in the extract that justify its lack of action against this fungal class. 

COMMITTEE MEMBERS:
Presidente - ***.101.014-** - EVILDA RODRIGUES DE LIMA - UFRPE
Externa ao Programa - 3195220 - FLAVIANE MARIA FLORENCIO MONTEIRO SILVA - UFRPEExterna à Instituição - IVANIA SOARES E LIMA
Externa à Instituição - EULINA TEREZA NERY FARIAS