Comparative effects of oral administration of Citrullus colocynthis and insulin injection on serum biochemical parameters of alloxan-induced diabetic dogs

Citrullus colocynthis seeds are traditionally used as antidiabetic medication in Mediterranean countries. An experiment was designed to evaluate the comparative effects of oral administration of C. colocynthis and insulin injection on the serum biochemical parameters of diabetic dogs. Twelve apparently healthy mixed breed dogs were selected and randomly allocated into three groups, two diabetic groups and one control group (n = 4). Diabetes was induced with alloxan tetrahydrate. One diabetic group and the control group were treated with a dose of 100 mg/kg/day of C. colocynthis. Three days after confirmation of diabetes mellitus, the dogs were orally administered C. colocynthis capsules twice daily for 8 days. The other diabetic group was injected with a combination of neutral protamine Hagedorn (NPH) [insulin isophane (NPH)–Human-Exir] and regular crystalline insulin [insulin (regular)–Human-Exir] (70% NPH and 30% regular) twice daily for 8 days. Blood samples were collected from the cephalic vein at three time points: immediately before alloxan injection, 3 days after diabetic induction, and 12 h after the last treatment. Serum concentrations of glucose, insulin, triglyceride, cholesterol, high-density lipoprotein, low-density lipoprotein, blood urea nitrogen, creatinine, alkaline phosphatase, alanine aminotransferase, and aspartic aminotransferase were measured. Results showed that the serum concentrations of glucose in insulin-injected dogs were not significantly different with those of the C. colocynthis-administered diabetic dogs. The serum concentrations of all measured parameters showed no significant change 8 days after the administration of C. colocynthis in the control group, whereas oral administration (capsule) of C. colocynthis at a dose of 100 mg/kg/day caused severe and mild diarrhoea in the control and C. colocynthis-treated diabetic groups, respectively. The present study indicated a significant antihyperglycaemic effect of C. colocynthis fruit and supports its traditional usage in the treatment of diabetes mellitus.