Several animal model studies have shown that Diabetes mellitus can affect on the activity of hippocampus astrocytes, but these studies reported controversial findings. This study was done to evaluate the preventive and treatment effect of Urtica dioica (U. dioica) on astrocytes density in the CA1 and CA3 subfields of hippocampus of streptozotocin (STZ) induced diabetic rats. Twenty-eight male albino Wistar rats were randomly allocated equally into control, diabetic, U. dioica treatment and U. dioica preventive groups. Hyperglycemia was induced by STZ (80 mg/kg/BW). One week after injection of the streptozotocin, animals in treatment group were received hydroalcoholic extract of U. dioica (100 mg/kg/BW /day) for 4 weeks by intraperitoneally. In preventive group, diabetic rats were received 100 mg/kg/BW/ daily hydroalcoholic extract of U. dioica for 5 days before STZ injection. Then, animals were sacrificed and coronal sections were taken from the right dorsal hippocampus, stained with PTAH. The area densities of the astrocytes were measured. The number of astrocytes in CA1 of controls, diabetic treatment and preventive groups was 19.00±5.5, 17.14±6.4, 21±8.1 and 16.48±3.2, respectively. The densities of astrocytes in CA3 of controls, diabetic, treatment and preventive groups were 25.45 ±7.60, 21.54±7.5, 23.75±5.6 and 19.89±3.8, respectively. The density of astrocytes in diabetic rats reduced in comparison with controls (P<0.05). In CA1 and CA3, in spite of preventive administration, treatment of diabetic rats with U. dioica significantly increased the astrocytes. This study showed that treatment with U. dioica extract can help compensate for the CA1 and CA3 subfields of hippocampus astrocytes in diabetic rats.

KEY WORDS: Diabetes; Astrocyte; Urtica dioica; Hippocampus; CA1; CA3; Rat.