Antihyperglycemic Effect of the Aqueous Extract of Foeniculum vulgare in Normal and Streptozotocin-induced Diabetic Rats

Background: Diabetes mellitus is associated with high blood glucose levels due to insulin shortcoming (insulinopenia) or defective insulin action. The objective of the study was to investigate the antidiabetic and antioxidant effects of Foeniculum vulgare in streptozotocin-induced diabetic rat. Methods: The effects of the leaves aqueous extract (LAE) of Foeniculum vulgare (F. vulgare) at a dose of 10 mg/kg on blood glucose levels were evaluated in normal and streptozotocin (STZ)- induced diabetic rats. Histopathological changes were also evaluated in liver in STZ-induced rats. Results: Single oral administration of F. vulgare LAE reduced blood glucose levels 6 h after administration in STZ diabetic rats (p<0.0001). Furthermore, blood glucose levels were decreased in both normal (p<0.05) and STZ diabetic rats (p<0.0001) after the fifteenth day of treatment. During this test, both groups did not show any significant change in their body weight. Moreover, this aqueous extract improved oral glucose tolerance in diabetic rats and revealed a positive effect on liver histology. On the other hand, the extract used in this experiment showed an inhibitory concentration (IC50) of 50% of free radicals with a concentration of 43±1.19 µg/ml. While the synthetic antioxidant (BHT) had an IC50 equal to 22.67±2.17µg /ml. Conclusion: This study demonstrates the antihyperglycemic, hypoglycemic and antioxidant effects of the leaves of F. vulgare in normal and diabetic rats.