Avaliação do potencial antiviral da Annona muricata (Graviola) e Spondias mombin (Cajá) contra o vírus dengue-2 em cultura de células

Abstract

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.