Banca de QUALIFICAÇÃO: KAREN SARTORI JEUNON GONTIJO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : KAREN SARTORI JEUNON GONTIJO
DATE: 03/07/2023
TIME: 13:30
LOCAL: Campus Centro Oeste Dona Lindu e Campus Alto Paraopeba (https://meet.google.com/mac-ndvw-qof)
TITLE:

Investigating the presence of action against Mayaro virus in plant species Tecoma stans, Smilax brasiliensis and Phyllanthus brasiliensis

KEY WORDS:

Keywords: Alphavirus; Arbovirus; Antivirals; Medicinal Plants

PAGES: 74
BIG AREA: Multidisciplinar
AREA: Biotecnologia
SUMMARY:

Until a few decades ago, the Mayaro virus (MAYV) was restricted to the sylvatic cycle, primarily between non-human primates and Haemagogus mosquitoes. Clinical infections in humans were considered accidental and limited to riverside populations. However, in recent decades, there has been an increase in the number of human cases of Mayaro fever, even with underreporting, especially in large urban centers. Recent reports indicate that MAYV, previously endemic only in the northern region of Brazil, has now been detected or suspected in at least 11 states, with Goiás being notable. This scenario suggests a geographical expansion of the virus, reaching urban areas beyond its previously known regions. Currently, there are no specific antiviral drugs or licensed vaccines against MAYV, which stimulates the search for antiviral treatments. In this line, plant extracts and compounds represent promising avenues for research. The aim of this study was to investigate the presence of antiviral activity in extracts from Tecoma stans, Smilax brasiliensis, and Phyllanthus brasiliensis species on MAYV-infected cells. Before conducting antiviral tests, cytotoxicity assays were performed to determine the 50% cytotoxic concentration (CC₅₀) of the extracts. Then, the effective concentration for 50% protection of infected cells (EC₅₀) against MAYV and the selectivity index (SI) for the different extracts were determined. For those with promising antiviral activity, further characterization of possible mechanisms of action and active principles was carried out. The results so far indicate that Tecoma stans extracts do not possess activity against MAYV. For Smilax brasiliensis, extracts containing fatty acids (AG) and fatty acid methyl esters (FAME) showed antiviral action with CE₅₀ values of 6.03 and 1.96 µg/mL, and SI of 7.3 and 75.68, respectively. For Phyllanthus brasiliensis, all four evaluated extracts showed robust antiviral activity, with CE₅₀ values ranging from 1.4 to 6.0 µg/mL and SI ranging from 90 to 337. Subsequent studies focused on the P. brasiliensis species, which demonstrated that hexane (16HEX) and hydroethanolic (19HET-60 and 22HET-95) extracts exhibited virucidal activity against MAYV, whereas the ethanol extract (18ET-100) had no effect on viral particles. When evaluating the antiviral action of these extracts during the viral adsorption stage, 19HET-60 and 22HET-95 showed a strong inhibitory effect. However, during the viral penetration stage, which is dependent on cellular enzymes, only 22HET-95 demonstrated effectiveness against MAYV. Therefore, the results so far indicate that P. brasiliensis is the most promising species, with compounds that can affect not only the viral particle (virucidal effect) but also cellular elements or pathways in the infection cycle. As only 22HET-95 showed viral inhibition in all evaluated mechanisms, initially, further studies will be conducted with this extract and two of its isolated compounds to identify active principles and any pharmacologically interesting products with antiviral action against the Mayaro virus.

BANKING MEMBERS:
Presidente - 1673648 - JOSE CARLOS DE MAGALHAES
Interna - 1742677 - JAQUELINE MARIA SIQUEIRA FERREIRA
Externo à Instituição - SERGIO OLIVEIRA DE PAULA - UFV
Externa à Instituição - CINTIA LOPES DE BRITO MAGALHÃES - UFOP