Evaluation of the Hypoglycemic Activity of Methanolic Extract of Foeniculum Vulgare in Streptozotocin-induced Diabetic Wistar Rats

Objective: This study aimed to assess the hypoglycemic effects of methanolic extract of Foeniculum vulgare in male Wistar rats that were diabetic due to streptozotocin. Methods: Experimental diabetes was initially induced in male Wistar rats by intravenous injection of streptozotocin (55 mg/kg). Subsequently, the rats received daily oral administration of the methanolic extract of Foeniculum vulgare (250 mg/kg) and the standard drug metformin (300 mg/kg) for 28 days. Furthermore, a tolerance test was carried out. Results: The study findings suggest that the diabetic rats in the untreated control group showed hyperglycemia and significant weight loss, as well as polydipsia, polyphagia, and polyuria. However, rats treated with methanolic extract of Foeniculum vulgare for 28 days showed a significant reduction in blood glucose levels and a marked improvement in body weight. Additionally, there was a notable decrease in the daily rate of food consumption and water intake and a significant reduction in serum glucose level, triglycerides, total cholesterol, creatinine, urea, AST, and ALT levels compared to the untreated diabetic control group. Histopathological examination revealed that after 28 days of treatment with 250 mg/kg of methanolic extract of the Foeniculum vulgare, the size of the islets of Langerhans in the pancreas tissue was decreased. Moreover, liver tissue demonstrated normalization with a normal central lobular structure, and kidney tissue showed normalization with a normal Bowman's capsule. Conclusion: These findings suggest that the methanolic extract of Foeniculum vulgare can potentially treat diabetes and should be evaluated further for drug development.