Banca de DEFESA: RODRIGO MICHELINI DE OLIVEIRA THOMASI

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RODRIGO MICHELINI DE OLIVEIRA THOMASI
DATE: 25/02/2024
TIME: 13:30
LOCAL: Plataforma Google Meet
TITLE:

Antiviral activity of Bauhinia holophylla leaves against Zika virus

KEY WORDS:

Pata-de-vaca, antimicrobial activity, arbovirus, medicinal plant, Cerrado.

PAGES: 78
BIG AREA: Ciências Biológicas
AREA: Microbiologia
SUBÁREA: Microbiologia Aplicada
SPECIALTY: Microbiologia Médica
SUMMARY:

Zika virus (ZIKV) belongs to the Flavivirus genus and had global attention in 2015-2016. In this period an outbreak occurred in Brazil, and remains a public health concern, especially for pregnant women. Unfortunately, there is a lack of specific treatments or vaccines available for Zika virus disease making prevention the primary mode of controlling its spread. As a potential solution to this issue, medicinal plants are a rich source of bioactive compounds with numerous therapeutic properties and have been explored for their potential to treat viral infections. The Bauhinia genus has approximately 300 species, also known as 'Pata-de-vaca' or 'Unha-de-boi', that are widely distributed and often used in folk medicine to treat infections, pain and diabetes. Bauhinia holophylla has demonstrated a promising anti-Dengue activity. In light of this, considering that ZIKV and Dengue virus share many similarities, including vectors, mode of transmission and symptoms, the present study aimed to investigate the anti-Zika virus in vitro activity of the extract and fractions of Bauhinia holophylla leaves. The crude hydroethanolic extract of the leaves was obtained by extensive percolation and liquid-liquid partitions were used to produce the hydroethanolic, dichloromethane and ethyl acetate fractions. To identify the samples, phytochemical analyses were performed using high-performance liquid chromatography with a diode-array detector and mass spectrometry (HPLC-DAD-MS). In order to evaluate the cytotoxicity and antiviral activity, the 50% cytotoxicity concentration (CC₅₀) and 50% effective concentration (EC₅₀) of the extract and fractions were determined by the 3-(4, 5- dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay using Vero cells. The concentrations of the extract and fractions tested ranged from 3.12 – 200 µg/mL and selectivity index (SI) was calculated by the ratio of CC₅₀ to EC₅₀. As results, the CC₅₀ results of all samples tested were between 92.4 to 191.1 µg/mL, showing moderate cytotoxic activity according to the NCI guidelines. With an EC₅₀ less than 15.0 µg/mL and SI of 13.4, the crude extract demonstrated the strongest anti-Zika activity. The results indicated that B. holophylla has a promising anti-Zika activity, which can be primarily attributed to the presence of flavonoids. To our knowledge, the biological activity of the Bauhinia genus has not been reported previously against ZIKV. Future research is required to evaluate antiviral mechanisms as well as in vivo studies

BANKING MEMBERS:
Presidente - 395916 - ANA HORTENCIA FONSECA CASTRO
Interno - 1222762 - ALEX GUTTERRES TARANTO
Externa à Instituição - SIMONY CARVALHO MENDONÇA - UFRJ
Externa à Instituição - GABRIELA FRANCINE MARTINS LOPES