doctoralThesis
Atividade antiviral de extratos brutos, ricos em polissacarídeos sulfatados, obtidos de macroalgas marrons e verdes contra o vírus dengue 2
Fecha
2016-06-14Registro en:
BEZERRA, Fabiana Lima. Atividade antiviral de extratos brutos, ricos em polissacarídeos sulfatados, obtidos de macroalgas marrons e verdes contra o vírus dengue 2. 2016. 135f. Tese (Doutorado em Bioquímica) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2016.
Autor
Bezerra, Fabiana Lima
Resumen
Dengue is considered the most important human arboviruses, and is a serious
public health problem. This disease is endemic in tropical and subtropical
regions, reaching more than 100 countries, which means the half of world
population, and those epidemies have been appellant. It is estimated that
Dengue virus could cause 390 millions of infections each year, and is an
important cause of morbidity. Although this scenario, actually doesn’t exist a
dengue antivirals still. Sorts of studies have showed antivirus activity of
seaweed sulfated polysaccharides against enveloped viruses, which action
seems to be associated to initials steps of infection process. In this study, was
evaluated the potential antiviral activity of crude extracts rich in sulfated
polysaccharides obtained from the brown algae Dyctiota menstrualis
(EBDMens) and Dyctiota mertensii (EBDM), and green algae Codium
isthmocladium (EBCl) and Caulerpa sertularioides (EBCS), tested against
Dengue virus 2 (DENV-2) in Vero cell line, by using different methodological
strategies (simultaneous treatment, post-infection treatment, cell pre-treatment,
virus pre-treatment, adsorption, post-adsorption and penetration). The extracts
cytotoxicity was evaluated by MTT reduction assay. The study of antiviral
activity was determinated by quantifying viral RNA load using RT-qPCR, after
120 hours of infection. None extract has showed toxicity against Vero Cells in
MTT reduction assay with 100 μg/mL concentration. All extracts have shown
antiviral activity when added during the first 90 minutes of infection, and a
significant reduction of viral RNA number of copies after 120 hours. The
EBDMens and EBDM extracts were more efficient to cell and virus pretreatment
assays, and the first has showed higher antiviral activity than EBDM
during viral adsorption. The EBCI and EBCS extracts have presented antiviral
activity very similar in cell pre-treatment assay. EBCI was more efficient in the
reduction of DENV-2 adsorption in Vero cell. However, EBCS has showed more
efficient in cell pre-treatment and penetration assays. Between the extracts
evaluated, EBCS seems to be more effective against DENV-2. These results
have showed potential action of extracts rich in sulfated polysaccharides with
antivirus activity, suggesting that they act in the initials steps of infection
process of DENV-2.