Influence of the Phytosynthesis of Noble Metal Nanoparticles on the Cytotoxic and Genotoxic Effects of Aconitum toxicum Reichenb. Leaves Alcoholic Extract

Phytosynthesis of Biological Active Silver Nanoparticles Using Echinacea purpurea L. Extracts

With their phytoconstituents acting as reducing and capping agents, natural extracts can be considered a viable alternative for the obtaining of metallic nanoparticles. The properties of phytosynthesized nanoparticles are dependent upon size and morphology, which, in turn, can be tailored by adjusting different parameters of the phytosynthesis process (such as the extracts' composition). In the present study, we aimed to evaluate, for the first time in the literature, the influence of the extraction method and extract concentration on the morphological and biological properties (antioxidant and antibacterial activity) of silver nanoparticles phytosynthesized using Echinacea pupurea L. extracts. The obtained results revealed that the use of the low-concentration Echinacea hydro-alcoholic extract obtained via classical temperature extraction led to the development of nanoparticles with the smallest dimensions (less than 10 nm), compared with the use of extracts obtained with higher concentrations and the extract obtained via the microwave method. The developed nanomaterials exhibited enhanced antioxidant effects (determined via the DPPH assay) and antimicrobial properties (against Escherichia coli and Candida albicans), compared with the parent extracts.

Phytosynthesized Metallic Nanoparticles-between Nanomedicine and Toxicology. A Brief Review of 2019's Findings

Phytosynthesized nanoparticles represent a continuously increasing field of research, with numerous studies published each year. However, with the emerging interest in this area, the quality of the published works is also continuously increasing, switching from routine antioxidant or antimicrobial studies on trivial microbial lines to antibiotic-resistant strains or antitumoral studies. However, this increasing interest has not been not reflected in the studies regarding the toxicological effects of nanoparticles (NPs); this should be a subject of greatest interest, as the increasing administration of NPs in general (and phytosynthesized NPs in particular) could lead to their accumulation in the environment (soil, water and living organisms). The present review aims to present the most recent findings in the application of phytosynthesized NPs as antimicrobial and antitumoral agents, as well as the results regarding their toxicological potential.