Banca de QUALIFICAÇÃO: DAMIANA ANTONIA DE FATIMA NUNES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : DAMIANA ANTONIA DE FATIMA NUNES
DATE: 23/10/2020
TIME: 09:00
LOCAL: Campus Centro Oeste Dona Lindu e Campus Alto Paraopeba (Via plataforma digital)
TITLE:

PROSPECTING ANTI-VIRAL ACTIVITY AGAINST ARBOVIRUS ZIKA AND MAYARO IN EXTRACTS AND COMPOUNDS ISOLATED FROM MAYTENUS QUADRANGULATA (CELASTRACEAE)

KEY WORDS:

ZIKV, MAYV, Maytenus sp., Antiviral

PAGES: 91
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Recently, the rate of appearance of some arboviruses has increased. Among them, there are cases referring to the Zika virus (ZIKV) and the Mayaro virus (MAYV) that started to have an increasing number of notifications. So far, there are no antiviral drugs or vaccines against these viruses, stimulating the search for antivirals, mainly due to the aggravations of these diseases that can be disabling to the patient. Molecules from plants stand out in this search, among them, those originating from the genus Maytenus, which presents compounds with well-described biological activities, making the species of the group candidates for prospecting for antivirals. The objective of this work was to prospect antivirals against the Mayaro and Zika viruses in extracts and compounds derived from leaves and branches of Maytenus quadrangulata. Initially, the cytotoxic concentration was determined for 50% of the cells (CC₅₀), using different extracts from the plant. Then, the effective protective concentration for 50% of the infected cells (EC50) and the selectivity index (IS) were obtained. The EHF, EAF and EAG extracts showed low cytotoxicity, with CC₅₀ of 547, 953,> 1000 ug / mL, respectively. As for the antiviral action against ZIKV, the EC50 occurred at concentrations of 25, 11 and 56 μg / mL, respectively. For MAYV, only EAF and EAG were effective, with EC50 of 12 and 101 μg / mL, respectively. The IS values were above 4, as recommended in the literature. In search of the principles of action, tests were performed with compounds isolated from the EHF extract. Despite the promising action of the extract, none of its isolates showed activity separately, indicating a possible synergistic action, which will be confirmed. The EAF and EAG extracts, which also showed antiviral action, were characterized by phytochemistry, and showed predominantly catechins in their composition, with greater antiviral selectivity for EAF. For this extract, the antiviral action was confirmed by other assays, showing a marked reduction in the viral cytopathic effect (ECP), reduction in the formation of viral plaques and inhibition of virus production in the culture supernatant, even when high viral load was used in infection. Finally, the characterization of possible mechanisms of action was initiated, with a virucidal effect for both viruses, not affecting the adsorption and penetration stages. Our data, taken together, show that M. quadrangulata extracts are effective in inhibiting ZIKV and MAYV, possibly due to the action of catechins, which, by binding to viral and non-cellular elements, are able to inactivate viruses even in high load. This study is the first to examine the antiviral effect and the mechanisms exerted by M. quadrangulata extracts on ZIKV and MAYV.

BANKING MEMBERS:
Interna - 395916 - ANA HORTENCIA FONSECA CASTRO
Interna - 1742677 - JAQUELINE MARIA SIQUEIRA FERREIRA
Interno - 1673648 - JOSE CARLOS DE MAGALHAES
Externo à Instituição - BRUNO EDUARDO FERNANDES MOTA - UFMG
Externo à Instituição - LEONARDO CAMILO DE OLIVEIRA - UFMG