Étude de l’activité antioxydante des extraits aqueux et hydroéthanoliques des feuilles et des tiges de Portulaca oleracea L.

Abstract

Medicinal plants are an important source of bioactive compounds that are attracting growing interest in the pharmaceutical, food, and nutraceutical industries. Among these plants, Portulaca oleracea L. is known for its high content of secondary metabolites, particularly phenolic compounds, which are believed to possess numerous biological activities, especially antioxidant activity. The objective of this study was to evaluate the antioxidant potential of aqueous and hydro-methanolic extracts from the leaves and stems of Portulaca oleracea L. The results of the phytochemical screening revealed variability depending on the extraction method and the plant part used. The extracts were found to be rich in secondary metabolites, notably flavonoids, tannins, quinones, and reducing sugars. Quantitative analysis revealed the presence of polyphenols at a concentration of 20.81 ± 0.008 mg EAG/100 g, flavonoids at 48.81 ± 0.245 mg EQ/100 g, and condensed tannins at 132.58 ± 0.034 mg EC/100 g. The evaluation of the antioxidant capacity of the various aqueous and hydro-ethanolic extracts, obtained using the DPPH free radical method, revealed varying inhibition percentages ranging from 84.47% to 25 μg/mL in the stem infusion extract, which was the highest value which confers on this plant good antioxidant activity closely linked to its high content of bioactive compounds, making it a promising natural source in the pharmaceutical and nutritional fields.