Calendula officinalis L. flower extract-mediated green synthesis of silver nanoparticles under LED light

Abstract Silver nanoparticles (AgNPs) are among the most known nanomaterials being used for several purposes, including medical applications. In this study, Calendula officinalis L. flower extract and silver nitrate were used for green synthesis of silver nanoparticles under red, green and blue light-emitting diodes. AgNPs were characterized by Ultraviolet-Visible Spectrophotometry, Field Emission Scanning Electron Microscopy, Dynamic Light Scattering, Electrophoretic Mobility, Fourier Transform Infrared Spectroscopy and X-ray Diffraction. Isotropic and anisotropic silver nanoparticles were obtained, presenting hydrodinamic diameters ranging 90 - 180 nm, polydispersity (PdI > 0.2) and moderate stability (zeta potential values around - 20 mV)

Development, Characterization and Microbiological Evaluation of Silver Nanoparticles, Obtained by Green Synthesis, from the Extract of Annona muricata L

Abstract Green synthesis is an efficient method, frequently applied in nanobiotechnology, as it does not use toxic reagents or solvents. Biological organisms, including medicinal plants, have been used successfully for manufacturing of different types of metallic nanoparticles. The aim of this work was to synthesize, characterize and evaluate the antimicrobial activity of silver nanoparticles (AgNPs) obtained from the extract of the pulp, seed and leaves of Annona muricata L. The particle size, polydispersity index, zeta potential, as well as morphological aspects of AgNPs were evaluated. With the data obtained from the analyses, we concluded that the nanoparticles were successfully obtained by a simple and green method using the aqueous extract of the pulp, seeds and leaves of A. muricata. AgNPs obtained by A. muricata pulp extract without exposure to artificial light showed lowest average of hydrodynamic diameter and smallest size at field emission scanning electron microscope (FESEM). In addition, these nanoparticles showed the best polydispersity index (PDI), and zeta potential of - 29.6, which indicates good stability. AgNPs obtained from the extract of the pulp, seed and leaves showed antimicrobial activity, against strains of gram positive and gram negative bacteria, and antifungal activity, compared to the pure extract.

Fitoterápicos: uma abordagem farmacotécnica / Herbal medicines: Pharmacotechnique approach

O artigo, de cunho informativo e crítico, propõe uma perspectiva de desenvolvimento de fitoterápicos sob a ótica da interdisciplinaridade, que envolve as inúmeras especificidades das diversas áreas que compõem o referido tema. Enumera-se a pesquisa de acordo com a antropologia botânica, a botânica, a agronomia, a fitoquímica, a farmacologia, a toxicologia, os aspectos de desenvolvimento e de estudo clínico do fitoterápico. Nesta perspectiva discute-se o fitoterápico inserido em uma proposta de construção de monografias nacionais de modo a contribuir com a indústria, com os centros estaduais, municipais de produção e distribuição de medicamentos, proporcionando dentre as opções de terapêutica um medicamento ético, seguro e eficiente.