Hypoglycemic medicinal plants used in Setif region and their effects on experimentally-induced diabetes in rats

Abstract

The objective of this study is to evaluate the antioxidant and antidiabetic activity of Olea europea, Trigonella foenum-graecum and Eucalyptus globulus extracts by Streptozotocin- induced diabetes by intravenous injection of 50 mg/kg of Streptozotocin. In this study, the results showed that methanolic extract (ME) and chloroformic extract (ChE) of Eucalyptus globulus leaves contained high polyphenolics and flavonoids contents, respectively, whereas ethyl acetate extract (EAE) of Olea europea leaves and Trigonelle foenum-graecum seeds contain the most important quantity in polyphenols and flavonoids. The obtained results from HPLC technique allowed the detection of phenolic compounds in methanolic extracts. In addition, ME of E.globulus showed a strong ABTS radical scavenging activity, and inhibited the linoleic acid oxidation in ferric thiocyanate method and TBA. While, the EAE of O.europea and T.foenum-graecum exhibited a good activity in reducing power, ABTS and TBA assays. After Induction of diabetes, the volume of urine and glucose increased and the body weight decreased in the untreated animals. The administration of MEO and MET at doses of 200 and 600 mg/kg and MEE at doses of 150 and 500mg/kg increased catalase activity, GSH level and decreased lipid peroxidation in the tissues of liver and kidneys, serum total cholesterol and triglycerides levels. Furthermore, histological damages in pancreas, kidney and liver tissues were reduced. These results indicated a good hypoglycemic and antioxidant activity of the three studied plants, could explain their use in folk medicine in the control of diabetes and preventing diabetic complications by scavenging free radicals.