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Previous issue date: 2015-03-13 === A dengue ? uma doen?a de notifica??o compuls?ria e cerca de 50 a 100 milh?es de casos s?o
registrados anualmente. Possui amplo espectro cl?nico e ? transmitida ao homem atrav?s da
picada dos mosquitos do g?nero Aedes, tendo como principal vetor a esp?cie Aedes aegypti. O
agente etiol?gico da doen?a ? o v?rus dengue (DENV) pertencente ao g?nero Flavivirus,
fam?lia Flaviviridae e s?o conhecidos quatro sorotipos antigenicamente distintos (DENV-1,
DENV-2, DENV-3 e DENV-4). Atualmente o tratamento da dengue ? apenas de suporte, feito
atrav?s de intensa hidrata??o. Ainda n?o existe uma vacina comprovadamente eficaz ou
tratamento espec?fico, o estudo de poss?veis antivirais que possam diminuir a viremia no
paciente ? de alt?ssima relev?ncia, uma vez que a carga viral ? um dos fatores associado ao
aparecimento das formas graves da doen?a (febre hemorr?gica da dengue e s?ndrome do
choque da dengue). No presente estudo n?s avaliamos o potencial antiviral de extratos brutos
obtidos a partir das folhas das plantas do Nordeste brasileiro Annona muricata (graviola) e
Spondias mombin (caj?) contra o DENV-2 em cultura de c?lulas C6/36 e Vero. A avalia??o
da a??o dos extratos brutos foi feita por meio da quantifica??o da carga viral atrav?s da PCR
em Tempo Real (qRT-PCR) e pela t?cnica de contagem de unidades formadoras de placa
(PFU). As concentra??es dos extratos de ambas as plantas utilizadas foram: 0,01, 0,1 e
1mg/mL. As culturas de c?lulas infectadas foram submetidas ao tratamento com os extratos
durante os per?odos de 24-168h horas (7 dias). C?lulas Vero tratadas com o extrato da S.
mombin n?o apresentaram redu??o na carga viral. Em contrapartida, quando estas c?lulas
foram tratadas com o extrato da A. muricata, uma hora ap?s infec??o, observou-se uma
redu??o significativa na carga viral nas primeiras horas (24h), quando comparadas com as
c?lulas n?o tratadas utilizadas como controle positivo. Ao serem tratadas em intervalos de 24
horas apresentaram uma redu??o na carga viral nos dias subsequentes (at? o s?timo dia). N?o
foi observada redu??o na carga viral em c?lulas C6/36 tratadas com ambos os extratos. De
acordo com os nossos resultados, o extrato da planta A. muricata possui potencial antiviral
promissor contra a infec??o pelo DENV-2 em cultura de c?lulas Vero. === Dengue is a reportable disease and about 50 to 100 million cases are reported annually. It has
a wide clinical spectrum and is transmitted to humans through the bite of Aedes mosquitos,
the main vector the Aedes aegypti species. The causative agent of disease is dengue virus
(DENV) belonging to the genus Flavivirus, family Flaviviridae and are known four
antigenically distinct serotypes (DENV-1, DENV-2, DENV-3 and DENV-4). Currently the
treatment of dengue is supportive, made by intense hydration. Although there is no proven
effective vaccine or specific treatment, the study of potential antiviral drugs that can reduce
viremia in patients is very high importance, since the viral load is one of the factors associated
with the development of severe forms of the disease (hemorrhagic fever dengue and dengue
shock syndrome). In the present study we evaluated the antiviral potential of crude extracts
obtained from the leaves of plants in Northeastern Brazil Annona muricata (soursop) and
Spondias mombin (caja) against DENV-2 in cultured C6/36 and Vero. The evaluation of the
activity of the crude extracts was performed by the quantification of viral load by RT-PCR
(qRT-PCR) and counting technique of plaque forming units (PFU). The concentrations of
extracts of both plants used were 0.01, 0.1 and 1 mg/mL. The infected cell cultures were
subjected to treatment with the extracts during periods of 24-168h hours (7 days). Vero cells
treated with the S. mombin extract showed no reduction in viral load. In contrast, when these
cells were treated with the extract of A. muricata, one hour after infection, significant
reductions in viral load in the first hour was observed (24 h) when compared to untreated cells
used as positive control. When they are treated at 24 hour intervals showed a reduction in
viral load in subsequent days (until day). There was no reduction in viral load in C6/36 cells
treated with both extracts. According to our results, the plant extract has antiviral A. muricata
promising potential against infection by DENV-2 in Vero cell culture.
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