LC-MS/MS analysis, antimicrobial and antioxidant potential of phenolic extracts derived from Urtica dioica leaves and roots

This research examined the antimicrobial and antioxidant properties of phenolic compounds from Urtica dioïca, a plant widely used in traditional medicine. The total polyphenol content in the leaves and roots were 5.37mg EAG/g and 1.21 mg EAG/g, respectively, while the flavonoid content was 0.40 mg QAE/g (leaves) and 0.19 mg QAE/g (roots). Using LC-MS/MS, 22 compounds were identified in the roots and 27 in the leaves, with gallic acid and 4-methylguaiacol found predominantly in both extracts. Unique to the leaf extract were Phenylethyl Ester and 3,5-Dimethoxyphenol. The extracts were tested against bacterial strains including Escherichia coli, Klebsiella, Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, and Proteus mirabilis, all showing sensitivity. MIC values ranged from 0.07 to 0.15mg/ml and MBC values ranged from 0.7 to 0.30mg/ml, indicating primarily bactericidal activity. Additionally, anti-free radical tests using DPPH showed 80.54% inhibition for the leaf extract and 49.23% for the root extract. This study highlights the significant antimicrobial and antioxidant properties of Urtica dioica, supporting its traditional medicinal use and suggesting its potential in developing novel therapies.