Impact of Metallic Nanoparticles on In Vitro Culture, Phenolic Profile and Biological Activity of Two Mediterranean Lamiaceae Species: L'Hér and G. López and R. Morales.

Nanoparticles (NPs) recently emerged as new chemical elicitors acting as signaling agents affecting several processes in plant metabolism. The aim of this work was to investigate the impact of the addition of copper oxide (CuO), zinc oxide (ZnO) and iron oxide (FeO) NPs (<100 nm) at different concentrations (1, 5 and 10 mg/L) to the culture media on several morphological, physiological and -biochemical parameters of in vitro shoot cultures of L'Hér and G. López and R. Morales (Lamiaceae), as well as on phenolic profile and bioactivity (antioxidant and enzyme inhibition capacities). Although some decreases in shoot number and length were observed in response to NPs, biomass production was not affected or was improved in both species. Most NPs treatments decreased total chlorophyll and carotenoid contents and increased malondialdehyde levels, an indicator of lipid peroxidation, in both species. HPLC-HR-MS analysis led to the identification of thirteen and twelve phenolic compounds, respectively, in and extracts, being rosmarinic acid the major compound found in all the extracts. ZnO and FeO NPs induced an increase in total phenolic and rosmarinic acid contents in extracts. Additionally, some NPs treatments also increased antioxidant activity in extracts from this species and the opposite was observed for . The capacity of the extracts to inhibit tyrosinase, acetylcholinesterase and butyrylcholinesterase enzymes was not considerably affected. Overall, NPs had a significant impact on different parameters of and in vitro shoot cultures, although the results varied with the species and NPs type.