Contribution à l’étude de l’impact des pesticides sur la qualité biochimique et l’activité biologique antioxydante de trois plantes de la région de Meniaa au Sud-Algérien

Abstract

Sahara plants have therapeutic characteristics that make them the ideal alternative to industrial medicines. Rhanterium adpressum, Helianthemum lippii and Oudneya africana are among the most important plants in the Algerian Sahara. Many studies have shown that they have been used locally since antiquity to treat several common diseases.

The objective of this study is to study the impact of pesticides on the biochemical quality and biological antioxidant activity of three species with traditional therapeutic use in the Meniaa region of Algerian Northern Sahara, in two different sites; one agricultural site and the other non-agricultural more or less far from the first. To do this, phytochemical screening tests are carried out to show the presence or absence of the main secondary metabolites of these plants. Extractions are carried out by aqueous maceration. The total polyphenols contents in the obtained raw extracts are then determined. The antioxidant potential of extracts obtained against free radicals DPPH and ABTS is subsequently assessed. Of all the results obtained, the phytochemical screening tests revealed the presence of several compounds of the secondary metabolism in the aerial part of the species from both sampling sites. The aerial parts of the plant species Helianthemum lippii appear to be the richest in total polyphenols with a maximum content of 212.33 µg EAG/g MVS in the aqueous crude extract. Tests of the antioxidant power have made it possible to evaluate the potency of aqueous raw extracts in the reduction and trapping of free radicals. The results obtained from the authorities inhibitor of the radical DPPH reveal that the isolated extracts are very active and general superior antioxidant activities with priority for aqueous raw extract of the species Helianthemum lippi (IC50 = 51.63 µg/mL).As for ABTS free radicals, the aqueous raw extracts of the same species showed the best antioxidant power (IC50 = 42.22 µg/mL). In short, the species Helianthemum lippi is almost the best in terms of richness biochemical polyphenolic compounds and antioxidant activity especially in the site where the pesticide is not found