Avaliação do potencial antiviral de produtos naturais

Abstract

Viral diseases are a huge problem for public health systems. What complicates the situation ofthese diseases is the lack of appropriate and specific medicines, as well as the resistance ofstrainsto available treatments and the lack of vaccinesto deal with these infections. Within thiscontext, diseases caused by Mayaro virus (MAYV) and Herpes simplex virus type II (HSV-2),are important infections from the health point of view in Brazil. The purpose of this work was to evaluate the antiviral activity of natural products against MAYV and HSV-2 viruses. The methodology has based on cytotoxicity assessment tests using MTT and potential antiviral activity using different methodological strategies. The results showed that most of the analyzedsamples were not cytotoxic at the highest concentrations tested or had cytotoxicity values at 50% (CC50) between >500 and <0.625 µg/mL. The potential of the antiviral against HSV-2 strain 333 of the total alkaloid fraction (FAT) of Fusaea longifolia (Aubl.) Saff. Moreover, theoil resin of Copaifera sp. has demonstrated which had selectivity indexes (IS) equal to 5.2. Bothsamples were promising mainly in relation to the virucidal activity presented values of 50% Virucidal Concentration of 76.42±18.86 and 78.60±16.88, respectively. In the FAT addition time assay, inhibition in viral replication was observed in the first hours of viral replication. The activity of FAT against HSV-333 may be related mainly to the alkaloids liriodenine and O-methylmoschatoline, which were identified structurally by mass spectrometry. Regarding theantiviral activity against the MAYV virus, it was found that a large part of the samples did notinhibit or had low percentages of inhibition of replication of this virus. The most promising samples were the ethanolic extract of Rosmarinus sp. (leaves), the dichloromethane fraction of Passiflora coccinea Aubl. and the dichloromethane fraction of Tagetes erecta L. (flower) whichshowed the highest percentages inhibitions against the MAYV virus, 35.50%±0.21,46.23%±1.41 and 55.15%±7.01, respectively.