Antioxidant and Antibacterial Properties of Leaf and Root Extracts of <i>Dipsacus fullonum</i>

Abstract Dipsacus fullonum L. (teasel) is a traditional medicinal plant, known to be a supplement in the treatment of Lyme disease. However, its scientific evaluation remains limited. This study investigates the phytochemical composition, antioxidant capacity and antibacterial properties of D. fullonum leaf and root ethanolic extracts. Ultrasound-assisted extraction with 70% ethanol was performed, and the extracts were analysed for total polyphenols, tannins and hydroxycinnamic acids. Antioxidant activity was assessed using the DPPH radical scavenging method, while antibacterial activity was evaluated via the broth microdilution method against various bacterial reference strains. Results indicate that leaf extract contains higher levels of bioactive compounds and exhibits stronger antioxidant activity than root extract. A combination of both extracts showed an additive effect. The leaf extract displayed weak antibacterial activity against selected Gram-positive and Gram-negative bacteria, whereas the root extract demonstrated no antibacterial effects.