Contribution à l’étude de l’activité hypoglycémiante des extraits de Pistacia atlantica Desf de la réserve nationale d’El-Mergueb (M'sila) -Algérie

Abstract

The current study aims to evaluate the antioxidant activity of the various extracts, as well as the toxic and antidiabetic effects of the crude extract (EBr) of Pistacia atlantica Desf leaves, plant used as traditional remedies for diabetes in Jordanie. The leaves were subjected to extraction and fractionation processes to give the different extracts: aqueous (EAq), crude (EBr), diethylic ether (EEde), ethyl acetate (EAe), the n-butanol (ENb), and aqueous fraction (EAq*). The quantitative analysis showed a significant presence of polyphenols and flavonoïdes in Pistacia atlantica leaves. While, EBr contains 340.58 ± 31.83 µg equivalent gallic acid (EAG)/mg of extract, EEde contains the highest amount of polyphénols (967.09 ± 47.05 µg EAG/mg of extract). The evaluation of the antioxydant activity revealed, not only, a significant scavenging effect of DPPH radical, but also a high inhibition of the coupled oxidation of β-carotène/acide linoleic (p<0.001), compared to standard antioxydants (acid gallic and BHT). Moreover, the study of acute toxicity showed that Pistacia atlantica leavesis not toxic with a DL50 equal to 11.380 g/kg of the body weight. On the other hand, the treatment of type 1diabetes (experimentally induced on albino Wistar rats by a single injection of the streptozotocine at a rate of 60 mg/kg ) for three weeks with EBr of doses 500 mg/kg, 250 mg/kg, and 125 mg/kg showed a remarkable reduction in the glycemia (for dose of 250 mg/kg) accompanied with maintaining lipidic profile (cholesterol and triglycerides), and a moderate increase of body weight compared to the normal rats, in addition to a non-significant reduction in the glycemia for the doses of 500 mg/kg and 125 mg/kg. The obtained results suggest that the significant antioxydant effect of the leaves of Pistacia atlantica Desf, and the prolonged use, as an antidiabetic agent, can constitute a natural resource of new substance used against the diabetes associated with oxidative stress.