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Silver nanoparticles (AgNPs) biosynthesized using aqueous medical plant extracts as reducing and capping agents show multiple applicability for bacterial problems. The aim of this study was to expand the boundaries on AgNPs using a novel, low-toxicity, and cost-effective alternative and green approach to the biosynthesis of metallic NPs using Calendula officinalis (Calendula) and Hyssopus officinalis (Hyssopus) aqueous extracts. The formation of AgNPs was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) techniques. The effectiveness of biosynthesized AgNPs in quenching free radicals and inhibiting the growth of Gram-positive and Gram-negative microorganisms was supported by in vitro antioxidant activity assay methods and using the Kirby–Bauer disk diffusion susceptibility test, respectively. The elucidated antimicrobial and antioxidative activities of medical plant extracts were compared with data from the engineered biosynthetic AgNPs. The antimicrobial effect of engineered AgNPs against selected test cultures was found to be substantially stronger than for plant extracts used for their synthesis. The analysis of AgNPs by TEM revealed the presence of spherical-shaped nano-objects. The size distribution of AgNPs was found to be plant-type-dependent. The smaller AgNPs were obtained with Hyssopus extract (with a size range of 16.8 ± 5.8 nm compared to 35.7 ± 4.8 nm from Calendula AgNPs). The AgNPs' presumably inherited biological functions of Hyssopus and Calendula medical plants can provide a platform to combat pathogenic bacteria in the era of multi-drug resistance. [ABSTRACT FROM AUTHOR]

In recent years, much attention has been devoted to Vaccinium L. berries because of their substantial potential to be adapted for the development of innovative food and pharmaceutical applications. The accumulation of plant secondary metabolites is extremely dependent on climate and other environmental conditions. In order to increase the reliability of the findings, this study was conducted with samples collected in four regions in Northern Europe (Norway, Finland, Latvia, and Lithuania) and analyzed in a single laboratory using a standardized methodology. The study aims to provide a comprehensive understanding of the nutritional (biologically active compounds (phenolic (477–775 mg/100 g fw), anthocyanins (20–57 mg/100 g fw), pro-anthocyanidins (condensed tannins (141–269 mg/100 g fw)) and antioxidant activity in different systems (ABTS•+, FRAP). Physicochemical properties (acidity, soluble solids, color) of wild Vaccinium vitis-idaea L. were also evaluated. The results may contribute to the development of functional foods and nutraceuticals with potential health benefits in the future. To the best of our knowledge, this is the first comprehensive report on the evaluation of the biologically active compounds of wild lingonberries from different Northern European countries based on one laboratory's validated methods. The results indicated a geomorphological influence on the biochemical and physicochemical composition of wild Vaccinium vitis-idaea L. depending on their place of geographical origin. [ABSTRACT FROM AUTHOR]