Antiviral activity of Myracrodruon urundeuva against rotavirus

ABSTRACT 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.

Antimicrobial, antiviral and cytotoxic activity of extracts and constituents from Polygonum spectabile Mart.

Polygonum spectabile is used in Brazil for treatment of several infection diseases. Extracts and constituents isolated from this species were evaluated for cytotoxicity and effects on 15 bacterias and yeasts as well on 4 viruses strains (HHV-1, VACV-WR, EMCV, DEN-2). Less polar extracts were effective against Staphylococcus aureus, Bacillus subtillis, Micrococcus luteus, M. canis and Tricophyton mentagrophytes and T. rubrum. Two known chalcones and 3-O-ß-D-glucosyl-ß-sitosterol were isolated. The ethanol extract was the only one to show antiviral activity (CE50 < 30 µg/ml). One chalcone has inhibited the growth of several bacteria and was significantly active against dermathophytes. The 3 compounds isolated have shown moderate cytotoxicity against Vero and LLCMK(2) cells (CC(50) < 50 µg/ml). These results support the use of P. spectabile as antimicrobial agent.

Avaliação da qualidade de amostras comerciais de folhas e tinturas de guaco / Evaluation of the quality of commercial samples of leaves and tinctures of guaco

O mercado brasileiro de fitoterápicos encontra-se em crescente expansão, porém a falta de padronização e a má qualidade da matéria-prima vegetal constituem um problema crucial na produção de fitoterápicos de qualidade. Neste trabalho, foram avaliadas drogas vegetais constituídas de folhas (amostras A, B, C) e tinturas (amostras D, E, F) de guaco, adquiridas no Mercado Central e em farmácias de manipulação de Belo Horizonte, respectivamente. Realizaram-se testes físicoquímicos de caracterização organoléptica, determinação de matéria estranha, teores de água e cinzas totais para as amostras de drogas vegetais e caracterização organoléptica, medidas de pH e de densidade para as amostras de tinturas. Foram obtidos os perfis cromatográficos por CCD e CLAE-FR e fez-se a quantificação da cumarina (marcador químico), por CLAE-FR. As amostras analisadas apresentaram um ou mais dos parâmetros avaliados fora dos valores preconizados pela farmacopéia brasileira, evidenciando-se a necessidade da realização do controle de qualidade de matérias-primas vegetais, para se obter medicamentos fitoterápicos de qualidade, eficientes e seguros.

The Brazilian market of herbal medicine is in increasing expansion; however, the lack of standardization and the bad quality of the plant raw materials constitute a crucial problem for the production of quality herbal medicines. In this work, herbal drugs consisting of leaves (samples A, B, C) and tinctures (samples D, E, F) of guaco purchased in the Central Market and from pharmacies in Belo Horizonte, respectively, were evaluated. Physical-chemical tests such as organoleptic characterization, determination of foreign matter, total ash and water content were performed on the samples of herbal drugs. The organoleptic characterization, measures of pH and density of the tincture samples were also determined. TLC and RP-HPLC profiles of the herbal drugs and tinctures were obtained and the quantification of coumarin (used as a marker compound) by RP HPLC was determined. The analyzed samples showed one or more of the evaluated parameters outside of the values recognized by the Brazilian Pharmacopoeia. This demonstrates the need for the quality control of the plant raw materials, in order to guarantee quality and safety in herbal medicine.