Contribution à l’étude phytochimique et évaluation de l’activité antioxydante de l’espèce Hammada scoparia des régions Ghardaia et Laghouat

Abstract

This study is intended to verify the antioxidant potential of some crude extracts of a plant species with therapeutic use in both of Ghardaia and Laghouat regions. To do that, some aqueous, methanolic and hydromethanolic crude extracts were prepared. Qualitative phytochemical screening tests and other quantitative assays were done in order to evaluate the major polyphenolic compound contents and their antioxidant activities towards free radicals were then assessed. The obtained result showed that the leaves of our plant species contains a very high levels, 86% of the crude extracts from Laghouat region species, and 54% from the plant samples of Ghardaia region. Similarly, the Laghouat region species was the richest one in polyphenolic compounds in its crude extracts. The antioxidant activity tests allowed to evaluate the potency of crude extracts in reducing or trapping free radicals.. The hydromethanolic extract of the leaves of the Ghardaia species proved to be the strongest natural antioxidant against the free radical DPPH with 264.12 ± 4.134 mg trolox Eq/ dry plant matter. In other hand, the aqueous crude extract of the leaves of the Laghouat species presented the strongest reducing power of ABTS free radicals with 344.319 ± 0.954 mg trolox E/ DPM. In brief, the aqueous, methanolic and hydromethanolic crude extracts of the aerial part of the Hammada scoparia species appear to be rich in compounds of secondary metabolism and possess generally a strong anti-radical power.