The infusion of Baccharis spicata (Lam. ) Baill (Asteraceae) has antiviral activity against hepatitis B virus without cytotoxic effects against several cell lines / La infusión de Baccharis spicata (Lam. ) Baill (Asteraceae) posee actividad antiviral contra el virus de la hepatitis B sin efectos citotóxicos contra varias líneas celulares

Medicinal plants are used to cure diseases, and their replacement is frequent and affects public health. The genus Baccharis has representatives within the medicinal flora of Argentina, although the replacement of the species of this genus known under the vulgar name of "carqueja" by Baccharis spicata has been detected i n herbalists or markets of herbal products. The genotoxic safety of this species has been established in previous work of our group. The aim of this study was to evaluate the antiviral activity of an infusion made from B. spicata leaves against hepatitis B virus with the HepG2.2.15 cellular system and to determine cytotoxicity in HepG2.2,15, A549 and Vero cell lines. Infusion of B. spicata was active to inhibit HBV replication with an EC 50 of 22.54 µg/mL and a CC 50 of 190 µg/mL.

Las plantas medicinales son empleadas para la cura de enfermedades, y su sustituc ión es frecuente y afecta a la salud pública. El género Baccharis posee representantes dentro de la flora medicinal de Argentina, aunque se ha detectado la sustitución de las especies de dicho género conocidas bajo el nombre vulgar de "carqueja" por Baccha ris spicata en herboristerías o mercados de productos herb arios . Se ha establecido la seguridad genotóxica de esta especie en trabajos previos de nuestro grupo. Este estudio buscó evaluar la actividad antiviral de una infusión elaborada a partir de hojas de B. spicata frente al virus de la hepatitis B con el sistema celular HepG2.2.15 y determinar la citotoxicidad en las líneas celulares HepG2.2.15, A549 y Vero. La infusión de B. spicata fue activa para inhibir la replicación del virus con un EC 50 de 22.54 µg/mL y un CC 50 de 190 µg/mL.

The role of the glycosyl moiety of myricetin derivatives in anti-HIV-1 activity in vitro.

BACKGROUND: Plant extracts are sources of valuable compounds with biological activity, especially for the anti-proliferative activity against pathogens or tumor cells. Myricetin is a flavonoid found in several plants that has been described as an inhibitor of Human immunodeficiency virus type 1 (HIV-1) through its action against the HIV reverse transcriptase, but myricetin derivatives have not been fully studied. The aim of this study was to evaluate the anti-HIV-1 activity of glycosylated metabolites obtained from Marcetia taxifolia and derived from myricetin: myricetin rhamnoside and myricetin 3-(6-rhamnosylgalactoside). METHODS: Compounds were obtained from organic extracts by maceration of aerial parts of M. taxifolia. All biological assays were performed in the MT4 cell line. Antiviral activity was measured as inhibition of p24 and reverse transcriptase with a fluorescent assay. RESULTS: Both flavonoids have antiviral activity in vitro, with an EC50 of 120 µM for myricetin 3-rhamnoside (MR) and 45 µM for myricetin 3-(6-rhamnosylgalactoside) (MRG), both significantly lower than the EC50 of myricetin (230 µM). Although both compounds inhibited the reverse transcriptase activity, with an IC50 of 10.6 µM for MR and 13.8 µM for MRG, myricetin was the most potent, with an IC50 of 7.6 µM, and an inhibition greater than 80%. Molecular docking approach showed correlation between the free energy of binding with the assays of enzyme inhibition. CONCLUSIONS: The results suggest that glycosylated moiety might enhance the anti-HIV-1 activity of myricetin, probably by favoring the internalization of the flavonoid into the cell. The inhibition of the HIV-1 reverse transcriptase is likely responsible for the antiviral activity.