Ação dos extratos de Byrsonima verbascifolia Rich. ex A. Juss contra rotavírus

Abstract

Rotaviruses belong to the family Reoviridae. Seven groups have been identified (A-G). The group A predominates in nature and is responsible for cases of diarrhea in humans. Rotavirus is the major causative agent of diarrhea and mortality in children under 5 years with an incidence of 100 million cases. Transmission occurs through fecal-oral route, person / person or by ingestion of contaminated food and water. Treatment is palliative and aims to maintain and restore the electrolyte balance of the patient. In this sense, the search for specific treatments are potential areas in the field of research. It is known that many herbal medicines may improve the processes of phagocytosis and still have microbicidal activity, being able to inhibit viral replication. The search for new antiviral drugs is one of the strategies to control this type of diarrhea, and plants and natural compounds have great applicability in therapy against Rotavirus. Thus, this study aims to evaluate the antiviral activity of crude and fractionated extracts of murici (B. verbascifolia) against Rotavirus. To determine the maximum concentration not cytotoxic crude and fractionated extracts, MA-104 cells were incubated with different concentrations of the extracts. The analysis was performed by optical microscope observation of morphological alterations, comparing cells treated and untreated. The maximum concentration of the extract that did not cause morphological changes were considered non-toxic. In the antiviral assay, 20 TCID50 of the reference virus (SA-11) were incubated in a monolayer of MA-104 cells, with crude and fractionated extracts at concentration of 25g/mL. The lowest cytotoxic effect was observed at concentrations of 50g/mL for crude extract and for its fractions. The antiviral assays with the crude extract showed 100% of antiviral activity against rotavirus. Afterwards the crude extract was fractionated (F1-F4) and new antiviral tests were performed. The percentage of inhibition (PI) of the extracts was verified using RT-PCR and virus titration techniques. There was a reduction in antiviral activity after the extract was fractionated, and the fractions F1 and F3 showed the highest activities with PI of 69% and 75%, respectively. The phytochemical characterization of these extracts revealed the presence of flavonoids, tannins, saponins and terpenes. The greater antiviral activity of crude extract and the decrease of activity after the fractionation may be related to the proportion of constituents and to a possible synergism between them. Our results open perspectives for the development of a treatment for rotavirus infection. Which could be need in the Unique System of Health (SUS). This system aims to guarantee access to health, in full, universal and free to all brazilian population.