Green synthesis of silver nanoparticles for application in cosmetics.

In this work, we analyzed the advantages of using silver nanoparticles (AgNPs) synthesized with natural extracts in ultraviolet-visible spectroscopy (UV-Vis) protective cream. The photodegradation properties of the new UV-Vis protective milk show an increase in its absorption band compared to AgNP-free cream. Previous to the study of the AgNPs mixed within the body milk, we studied the optical UV-Vis properties of extracts at different collection times, as they can influence the spectral range of UV-Vis absorption of the hybrid compound (AgNPs + natural extract). Shape and size of the AgNPs differs from the type of reducing agent as well as the concentration of silver nitrate used. We also compared the cytotoxicity in cell lines and the antibacterial effect of the AgNPs without and with organic coating. All these studies showed that we obtained hybrid sun-protective body milk with a high degree of solar protection and with low cytotoxicity at a cellular level, thus improving its protective properties. The synthetized hybrid compound could be a possible cost-affordable alternative for the market.

ESTIMULACIÓN DE GERMINACIÓN Y COLONIZACIÓN RADICULAR DE Diversispora trimulares POR FLAVONOIDES DE EXUDADOS RADICULARES DE Nicotiana glauca / STIMULATION OF GERMINATION OF SPORES AND ROOT COLONIZATION OF Diversispora trimulares BY FLAVONOIDS IN Nicotiana glauca ROOT EXUDATES

Los metabolitos secundarios son señales importantes en la interacción planta-microrganismos; sin embargo, los datos que corroboran el rol de los flavonoides como señales entre plantas y la simbiosis micorrízica arbuscular son limitados y aún recientes. Este estudio tiene por objetivo evaluar el efecto de flavonoides presentes en exudados radiculares de Allium porrum L., Nicotiana gluaca y Brassica oleracea var. Itálica, en la germinación de esporas y establecimiento de colonización radicular de Diversispora trimulares. Se detectaron miricetina y canferol en exudados de A. porrum, con un contenido total de flavonoides de 23,80µg g-1, de raíz seca; quercetina, en N. glauca, con 23,35µg g-1 y crisina, en B. oleracea, con 14,71µg g-1. Quercetina estimuló la germinación y la vitalidad de esporas (24%, 40%), a diferencia de crisina, que presentó un efecto inhibitorio (4%, 20%). A. porrum y N. glauca incrementaron la germinación de esporas (54%, 56%) y porcentaje de colonización de micorriza arbuscular (72%, 75%). Los resultados de la investigación mostraron una evidencia sólida del efecto de los flavonoides como moléculas estimulantes en los procesos de germinación de esporas y colonización de micorriza arbuscular.

Secondary metabolites are important signals that could determine the outcome of the plant soil microbial interactions, however, the data available that support the leading role of flavonoids in the communication of arbuscular mycorrhizal symbiosis are recent and limited. The present study examines the effect of flavonoids detected in root exudates from Allium porrum, Nicotiana glauca y Brassica oleracea var. italica on spore germination and mycorrhizal root colonization of Diversispora trimulares. Myricetin and kaempferol were detected in A. porrum root exudates with a total flavonoid content of 23.80µg g-1 dried root, quercetin in N. glauca with 23,35µg g-1 and chrysin in B. Oleracea with 14.71 µg g-1. Quercetin increased the spore germination and vitality (24%, 40%). In contrast, chrysin showed an inhibitory effect (4%, 20%). A. porrum and N. glauca increased spore germination (54%, 56%) and root mycorrhizal colonization (72%, 75%). This results evidence the effect of flavonoids on the stimulization of spore germination and stablishment of root colonization of arbuscular mycorrhizal fungi.