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Taking into account the increasing number of antibiotic-resistant bacteria, actual research focused on plant extracts is vital. The aim of our study was to investigate leaf and stem ethanolic extracts of Artemisia absinthium L. and Artemisia annua L. in order to explore their antioxidant and antibacterial activities. Total phenolic content (TPC) was evaluated spectrophotometrically. Antioxidant activity was evaluated by DPPH and ABTS. The antibacterial activity of wormwood extracts was assessed by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Salmonella enteritidis cultures, and by zone of inhibition in Klebsiella carbapenem-resistant enterobacteriaceae (CRE) and Escherichia coli extended-spectrum β-lactamases cultures (ESBL). The Artemisia annua L. leaf extract (AnL) exhibited the highest TPC (518.09 mg/mL) and the highest expression of sinapic acid (285.69 ± 0.002 µg/mL). Nevertheless, the highest antioxidant capacity (1360.51 ± 0.04 µM Trolox/g DW by ABTS and 735.77 ± 0.02 µM Trolox/g DW by DPPH) was found in Artemisia absinthium L. leaf from the second year of vegetation (AbL2). AnL extract exhibited the lowest MIC and MBC for all tested bacteria and the maximal zone of inhibition for Klebsiella CRE and Escherichia coli ESBL. Our study revealed that AbL2 exhibited the best antioxidant potential, while AnL extract had the strongest antibacterial effect.

Elderberry growth phases represent an irreversible process involving a series of biochemical changes that have an extremely important impact on nutritional characteristics. The aim was to assess the impact of genotype and maturity stage on phenolic compounds, antioxidant capacity and mineral profile in Sambucus plants harvested during different growth phases, from green elder flower buds to purple-black elderberries, including pollen, peduncles and seeds. Growth phases proved to have a greater influence compared to varieties. The green buds and flowers of both varieties had a high concentration of quercetin 3-rutinoside, also termed the key compound of the study. It was found that antioxidant activity varied in the following order: blooming elder flower pollen > white elder flower buds > blooming elder flowers. Based on these findings, several novel food ingredients and supplements could be obtained in order to develop innovative health-promoting products.