Évaluation de l'activité antioxydante D’Urtica urens L. de la région de Mostaganem

Abstract

Oxidative stress, resulting from an imbalance between the production of reactive oxygen species (ROS) and the body's antioxidant defences, is now recognized as a key factor in the development of numerous chronic pathologies (cancers, cardiovascular and neurodegenerative diseases). Given the limitations of synthetic antioxidants, the search for natural antioxidant sources from the plant kingdom has attracted growing interest. In this context, the present study aims to evaluate the antioxidant activity of the methanolic extract of Urtica urens L. (small nettle) leaves, collected from the Sidi Berhal region (Mostaganem, Algeria), using the DPPH free-radical scavenging test, and to compare it with that of ascorbic acid (vitamin C), a reference antioxidant. Extraction was carried out using an ultrasound-assisted method with pure methanol (99.7%), yielding an extraction rate of 7.85%. The results reveal a notable antiradical activity of the extract, with a median inhibitory concentration (IC₅₀) of 15.34 μg/ml, compared to 6.41 μg/ml for ascorbic acid. This activity is attributed to the plant's richness in phenolic compounds and flavonoids. The results, compared with the literature on Urtica urens and other Urtica species, as well as with other medicinal plants and synthetic antioxidants, confirm the potential of Urtica urens L. as a natural source of antioxidants with applications in the food, cosmetic, and pharmaceutical industries.