LAUSR

In this research paper, the total phenols (TP), flavonoids (TF), and tannins (TT) content in the acetone and ethyl acetate extracts of Najas marina L. and the identification and quantification of phenolic acids and flavonoids from the ethyl acetate extract were performed. Antioxidant, antimicrobial, and antibiofilm properties of the mentioned extracts were investigated in vitro. The genotoxic potential was analyzed in cultured human peripheral blood lymphocytes (PBL). The TP and TF content was higher in the ethyl acetate extract, dominated by quercetin (172.4 µg mg-1) and ferulic acid (22.74 µg mg-1), while the TT content was slightly higher in the acetone extract. Both extracts tested showed limited antioxidant effects compared to ascorbic acid. The strongest antibacterial activity was observed with Gram-positive bacteria, particularly Staphylococcus aureus (MIC and MMC at 0.31 mg ml-1) and S. aureus ATCC 25923 (MIC at <0.02 mg ml-1), while antifungal activity was limited. Both extracts tested showed better activity on preformed biofilms. Acetone extract had no genotoxic activity but showed significant genoprotective activity against mitomycin C-induced DNA damage in cultured PBLs. Results of our research demonstrate the potential for the development of plant-based antibacterial and biofilm agents.