Étude phytochimique et activité antioxydante de l'espèce Asteriscus graveolens de la région de Ghardaïa

Abstract

This work is devoted to the phytochemical study and antioxidant activity of the species Asteriscus graveolens (Asteraceae) endemic to the Sahara in Algeria. crude extract is prepared by hydroalcoholic maceration followed by liquid-liquid extraction with solvents of increasing polarities in order to fractionate the crude extract into three phases. The quantitative analysis of the extracts is carried out by measuring the content of polyphenols, flavonoids and tannins. The estimation of the antioxidant activity of the extracts was evaluated by the DPPH and phosphomolybdate test. The results obtained show that the extracts of A. graveolens contain significant quantities of natural phenol and natural flavonoids but poor in natural tannin. The dichloromethane extract was richest in flavonoids and tannins, while the acetate extract was richest in tatal phenols. All extracts demonstrated excellent free radical scavenging activity where ethyl acetate extract demonstrated the best antioxidant activity via DPPH test with a value of IC50 =0.0042 and total antioxidant activity with a value of EC50 =0.0892. This activity may be due to the chemical nature of the compounds present in these extracts. These results justify the use of this plant in traditional medicine.