The production and extensive use of silver nanoparticles (AgNPs) in various fields necessitate thorough testing, not only in terms of their potential applications but also regarding the effects they induce on various organisms. In addition, nanoparticles generated from various anthropogenic activities, which reach or are formed in the atmosphere, have a significant impact on the health of humans and other living organisms. Recent research indicates that the effects produced by these nanoparticles are dependent on their size and applied dose. In this context, the present study aimed to evaluate the physiological, biochemical and cytogenotoxic effects induced by different doses of AgNPs compared to positive and negative controls in Triticum aestivum L. and Allium cepa L. A significant stimulatory effect of the treatment performed with the solution of AgNPs with a size of 20 nm, at the lowest concentration (0.02 µg mL−1), in the two tested species, was obtained. The growth and weight of the seedling were significantly increased, and the mitotic index was also elevated. Additionally, this treatment variant showed the lowest percentage of chromosomal aberrations. No significant differences were observed in cell viability, total polyphenol content, proline levels, or assimilatory pigment concentrations compared to the control. Our findings show that AgNPs may exert stimulatory effects, whether significant or not, on certain physiological and biochemical parameters. However, they also interfere with cell cycle regulation and genomic stability, raising concerns regarding their environmental and biological safety. The Allium test proved to be an effective method for detecting nanoparticle-induced genotoxicity and can be recommended as a preliminary screening assay in nanoparticle safety evaluations.
Ferns are vascular plants with significant ornamental value, and in recent years, they have also been considered for the potential application in different economic sectors like nutrition, medicine and cosmetics. This study aimed to obtain in vitro fern gametophytes and sporophytes and evaluate their potential as secondary metabolites sources. For this study four fern species were used: Polypodium vulgare L. (PV), Asplenium trichomanes L. (AT), Athyrium filix-femina L. Roth (AF), and Osmunda regalis L. (OR). The polyphenols, flavonoids, tannins and terpenoids content and antioxidant activity were estimated by different colorimetric methods. For metabolite identification and their antioxidant activity, HP-TLC separations were used. Also, quantitative HPLC–DAD analysis was performed to estimate the content of certain metabolites. The results showed that in vitro generation of gametophytes registered higher growth rates in OR, PV, and AF, while the regeneration of sporophytes was better for PV, AT, and AF. The OR gametophyte produced the highest quantities in all analyzed metabolite classes and also had the highest antioxidant values. We report for the first time the presence of metabolites such as catechin, caffeic acid, gallic acid, ferulic acid, cinnamic acid, or rutin in OR. In this study, we demonstrated the possibility of producing potent antioxidant metabolites by in vitro cultures in ferns.
The evaluation of local natural resources and their sustainable use as alternatives for allopathic medicines or phytosanitary treatments based on chemical syntheses, is a priority of research worldwide. The aim of this research was to obtain Prunella vulgaris L. extracts through modern, ecofriendly methods, to evaluate their ability to biosynthesize silver nanoparticles (AgNPs), as well as the physicochemical characterization of AgNPs to determine the polyphenol content, antioxidant and antimicrobial activity as well as phytotoxicity of the resulting nanoformulations, through in vitro tests. Microscopic analysis of the extracts showed the spherical shape of AgNPs, especially in the biosynthesized samples from the microwave extracts. The sizes of the nanoparticles ranged between 8.64 and 13.84 nm. Microwave-assisted extraction favored the procurement of crude extracts from P. vulgaris herba with a high content of polyphenols (77.98 mg GAE/g dw−1) and a correlated antioxidant activity. Rosmarinic acid was identified in all analyzed samples (61.8287–1.0031 mg/L). The extracts obtained using microwaves, in which the nanoparticles were also biosynthesized using microwaves, had the best antifungal activity against Fusarium oxysporum MUCL 791. The combination of antifungal properties with those of seedling growth stimulation are of major importance in plant culture, with the early stages of their life cycle requiring constant attention.