Evaluation In Vitro du pouvoir antioxydant de deux plantes de la famille des Asclépiadacées dans la région de Ghardaïa

Abstract

Traditional medicines and the use of medicinal plants in empirical or modern medicine have commonly been the source of basic and high-level scientific research. In this work, we assessed the antioxidant power of crude aqueous extracts of the aerial and underground parts of two plant species of the Asclepiadaceaes family, using three preparation methods: infusion, decoction and maceration. These species are: Pergularia Tomentosa (from Zelfana) and Calotropis procera (from Metlili) in the Ghardaia region. Phytochemical screening tests were carried out to identify the presence or absence of the main secondary metabolites of the two plants. Extractions were carried out by aqueous maceration. The total polyphenol content of the crude extracts obtained was then determined. The antioxidant potential of the extracts obtained against DPPH and ABTS free radicals was then assessed. From most of the results obtained, the phytochemical screening tests revealed the presence of secondary metabolism compounds in the aerial part more than in the underground part. The Calotropis procera species was found to be richer in total polyphenols, with a maximum content of around 501.96 mg EAG/g MVS in the crude extract obtained by decoction. Antioxidant potency tests were used to assess the potency of crude aqueous extracts in reducing and trapping free radicals. The results obtained for DPPH radical inhibiting power show that the extracts isolated much more by maceration are very active and have strong antioxidant powers, with priority given to the crude aqueous extract of the Calotropis procera species (IC50 = 49.691 µg/ mL). As for ABTS free radicals, the aqueous crude extracts of the same species showed the best antioxidant power (IC50 = 0.278 mg/ mL).