Antibiofilm, Antimicrobial, and Anti-inflammatory Potential of Rubus chamaemorus Rhizome, Leaf, and Fruit Extracts.

The global rise of antimicrobial resistance is concomitant with an increasing prevalence of chronic wound infections. Medicinal plants are a promising source of novel therapeutic agents. Rubus chamaemorus, a plant native to Northern Europe traditionally used for wound healing, is one of them. Dried, powdered rhizomes, leaves, and fruits of R. chamaemorus were extracted with dichloromethane, methanol, and water. The extracts were screened for antibacterial and antifungal activity. Main compounds were identified using liquid chromatography-mass spectrometry (LC-MS). Biofilm inhibition was assessed using multidrug-resistant Escherichia coli. Cytotoxicity against HaCaT cells, inhibition of 5-lipoxygenase (5-LOX) product formation, chelating, and antioxidant properties were determined. While the rhizome and fruit extracts demonstrated no relevant biological activities, the methanolic leaf extract exhibited a low minimal biofilm inhibitory concentration (MBIC = 30 µg/mL) and a potent 5-LOX inhibition (IC50 = 1.5 ± 0.5 µg/mL). These properties are likely linked to the pronounced chelating and antioxidant properties of the extract. No cytotoxicity was observed in HaCaT cells and human primary monocytes (up to 200 and 30 µg/mL, respectively). LC-MS analysis of the leaf extracts identified flavonoid glycosides as predominant compounds. These findings support the plant's traditional use in wound healing. Bioactivity-guided fractionation is imperative to identify and characterize the active compounds.