Biochemical characterization, antioxidant and antidiabetic properties of <i>Zygophyllum geslini</i> Coss extracts

Zygophyllum geslini Coss. is a medicinal plant growing wild in the northern Sahara of Algeria, belonging to Zygophyllaceae family. The objective of this study was to evaluate some biochemical properties of the aqueous lyophilized extract and the methanol leaf extracts of this plant, their antioxidant and antidiabetic activities were also tested. The content of total phenols, flavonoids and tannins detected in the methanol extract (183.22 mg Gallic acid equivalent/g Dry Extract, 101.13±0.02 mg Quercetin equivalent /g Dry Extract, 54.07±0.98 mg Tannic acid equivalent/g Dry Extract respectively) was higher than those detected in aqueous lyophilized extract. The best DPPH scavenging activity was found in the methanol extract followed by the aqueous lyophilized extract (IC50=65.36 and 67.44 µg/ml, respectively), but still less effective than the positive controls. This two extracts showed also a very good ferric reducing activity. In addition, animals treated with the methanol extract showed a significant decrease in blood glucose level and glycosylated hemoglobin. A significant increase was observed in serum insulin and liver glycogen levels. This study reveals that the methanol extract of Z. geslini can be considered as excellent candidate for future studies on diabetes mellitus.