Antiviral activity of Myracrodruon urundeuva against rotavirus

Myracrodruon urundeuva Allemão, Anacardiaceae, is a medicinal plant widely found in Brazil, especially in the northern region. In our previous study, the ethanolic extract from leaves of M. urundeuva showed antiviral activity against simian rotavirus SA-11. Here, the crude extract was subjected to fractionations in order to subsequently work with more concentrated and pure bioactive compounds, which were analyzed by TLC and HPLC methods to support a better understanding of their virucidal effect. The antiviral activity was evaluated using a rotavirus infection model in MA-104 cells treated with the maximum non-cytotoxic concentration of the crude extract and its fractions. Data were expressed as the percentage inhibition of viral replication calculated by the inhibition of cytopathic effect in the treated cells compared to untreated controls after 48 h of incubation. First, we conducted a fractionation, generating five fractions (F1–F5) which were submitted to antiviral assay. Then, the fraction that showed the highest virucidal effect (F3, PI = 75%) was subjected to a larger partition, yielding eighteen subfractions, which were submitted to new antiviral assays. Terpenes, flavonoids and tannins were the major secondary metabolites detected by TLC analysis in F3. SF1, a flavonoid-enriched fraction, showed the strongest in vitro activity against rotavirus (PI = 92%), preventing cytopathic effect. Chromatographic profiles were obtained by HPLC for the crude extract and SF1, the most potent subfraction. Overall, our data point to the potential anti-rotavirus activity of flavonoid-enriched fraction (SF1) of M. urundeuva leaves, corroborating the traditional use of this species to treat diarrhea and broadening our perspectives on in vivo assays in mice with SF1 isolated or associated with other fractions.