Antimicrobial, Antioxidant, Cytotoxic Activity And Phytochemical Screening Of Secondary Metabolites From Urtica Dioica

Abstract

Urtica dioica, also called as stinging nettle which has been traditionally used for medicinal properties. The aim of this study to evaluate the antimicrobial, antioxidant, cytotoxic activities, and phytochemical screening of secondary metabolites that extracted from the plant (Urtica Dioica). Plant leaves were collected, identified, and processed to obtain methanolic extracts. The extraction process was followed by comprehensive phytochemical screening and experimental assays to evaluate the biological properties of the extracts. Phytochemical analysis confirmed the presence of key secondary metabolites, including polyphenols, alkaloids, tannins, triterpenes, and saponins. Gas Chromatography-Mass Spectrometry analysis further identified major bioactive compounds such as quercetin (3.43%), kaempferol (0.03%), caffeic acid (0.03%) beta- sitosterol (0.05%), and ferulic acid (0.5%). The antibacterial activity, assessed via the agar well diffusion method, demonstrated notable inhibitory effects against bacterial strains, with the highest activity observed against P. mirabilis (26.5 mm) followed by E. coli (26 mm), P. aeruginosa (24.5 mm), S. mutans (21 mm), and B. subtilis (18.5 mm) at a concentration of 100 mg/ml. Antifungal activity revealed inhibition zones of 16.2 mm and 14.5 mm for Candida albicans and Aspergillus niger, respectively. Cytotoxic activity was evaluated using the brine shrimp lethality assay, where lethality rates were concentration- dependent, with the highest activity recorded at 1000 µg/ml (20.67%). The DPPH radical scavenging assay was used to measure antioxidant activity, demonstrating the methanolic extract's capacity to efficiently neutralize free radicals. The findings highlight Urtica dioica's potential as a rich source of bioactive compounds with significant therapeutic applications, particularly for antimicrobial, antioxidant, and cytotoxic purposes. These results emphasize the plant's utility in pharmaceutical and nutraceutical industries.