Urtica dioica Aqueous Leaf Extract: Chemical Composition and In Vitro Evaluation of Biological Activities

Urtica dioica L. has been used as a natural remedy due to its healing properties for over 2000 years. The aim of this study is to investigate the chemical composition, antimicrobial, antioxidant, and antitumor properties in vitro of the aqueous extract of Urtica dioica leaves (AEUD). The chemical composition was assessed by an ultra-high-performance liquid chromatography system coupled to a benchtop QExactive high-resolution accurate mass spectrometry operating in a data-dependent acquisition mode as a non-target approach. Minimal inhibitory concentration (MIC) and disc diffusion were used to assess the antibacterial efficacy against nine bacterial strains. The antioxidant impact was assessed using DPPH, ABTS, FRAP, and ferrous ion-chelating ability assays. By using the MTT method, the cytotoxicity effect of AEUD on colon cancer cell HCT-116 was evaluated. Flow cytometry was used to analyze the cell cycle. Finally, the anti-migration and anti-invasion properties of AEUD on HCT-116 cells were estimated using the wound healing test and Transwell assays. AEUD is a rich source of phenolic compounds. The results of disc diffusion and MIC showed that the AEUD is more active against Gram-positive bacteria than against Gram-negative bacteria. MTT assay confirmed that the AEUD inhibited HCT-116 colon cancer cell proliferation. Findings of flow cytometry confirmed that cell cycle arrest occurred at the G2 phase. Additionally, AEUD had anti-migration and anti-invasion effects. This study shows that Urtica dioica aqueous leaf extract exhibits potential antibacterial, antioxidant, and antitumoral activities on HCT-116 colon cancer cells.