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.

Physiological and transcriptional responses of Baccharis halimifolia to the explosive "composition B" (RDX/TNT) in amended soil.

Unexploded explosives that include royal demolition explosive (RDX) and trinitrotoluene (TNT) cause environmental concerns for surrounding ecosystems. Baccharis halimifolia is a plant species in the sunflower family that grows naturally near munitions sites on contaminated soils, indicating that it might have tolerance to explosives. B. halimifolia plants were grown on 100, 300, and 750 mg kg(-1) of soil amended with composition B (Comp B) explosive, a mixture of royal demolition explosive and trinitrotoluene. These concentrations are environmentally relevant to such munitions sites. The purpose of the experiment was to mimic contaminated sites to assess the plant's physiological response and uptake of explosives and to identify upregulated genes in response to explosives in order to better understand how this species copes with explosives. Stomatal conductance was not significantly reduced in any treatments. However, net photosynthesis, absorbed photons, and chlorophyll were significantly reduced in all treatments relative to the control plants. The dark-adapted parameter of photosynthesis was reduced only in the 750 mg kg(-1) Comp B treatment. Thus, we observed partial physiological tolerance to Comp B in B. halimifolia plants. We identified and cloned 11 B. halimifolia gene candidates that were orthologous to explosive-responsive genes previously identified in Arabidopsis and poplar. Nine of those genes showed more than 90% similarity to Conyza canadensis (horseweed), which is the closest relative with significant available genomics resources. The expression patterns of these genes were studied using quantitative real-time PCR. Three genes were transcriptionally upregulated in Comp B treatments, and the Cytb6f gene was found to be highly active in all the tested concentrations of Comp B. These three newly identified candidate genes of this explosives-tolerant plant species can be potentially exploited for uses in phytoremediation by overexpressing these genes in transgenic plants and, similarly, by using promoters or variants of promoters from these genes fused to reporter genes in transgenic plants for making phytosensors to report the localized presence of explosives in contaminated soils.

Baccharis trimera (Less.) DC as genotoxicity indicator of exposure to coal and emissions from a thermal power plant.

During coal combustion, hazardous elements are discharged that impair environmental quality. Plant cover is the first available surface for the atmospheric pollutants in terrestrial ecosystems. The aim of this study was to evaluate genotoxicity in the aqueous extract of the native plant, Baccharis trimera, exposed to coal and emissions from a thermal power plant (coal-fired power plant in Candiota, Brazil), correlating seasonality, wind tunnel predominance, and presence of inorganic elements. The presence of inorganic elements in the aerial parts of B. trimera was analyzed by particle-induced X-ray emission (PIXE) spectrometry, and genotoxicity was evaluated by ex vivo comet assay. The genotoxic effects of aqueous extracts of B. trimera from four sites located in the area around power plant were analyzed by comet assay in peripheral human lymphocytes. Winter samples showed greater levels of metals than summer samples. Genotoxicity was detected in B. trimera extracts collected from the region exposed to extraction and burning coal. Extracts from the site impacted by the dominant wind induced more damage to DNA than those from other sites. Based on our data, we can suggest that in winter the inorganic elements from extraction and burning of coal and carried through the wind tunnel were responsible for the genotoxicity observed in aqueous extract of B. trimera.