GOLALIPOUR, M. J.; GHAFARI, S.; LATIFIMOGHADAM, M. H. & KABOLI, S.Alteration of dentate gyrus astrocytes in diabetic rats: Protective role of Urtica dioica. Int. J. Morphol., 29(4):1307-1312, 2011. SUMMARY:Diabetes mellitus can cause astrocytes alterations in the central nervous system. Urtica dioica (Nettle) is among several species listed for their use against diabetes in folk medicine. Therefore, this study was done to evaluate the protective effect of Urtica dioica on astrocytes density of the dentate gyrus in STZ induced diabetic rats. In this experimental study, 21 male albino Wistar rats were randomly allocated equally into normal, diabetic and protective (nettle treated diabetic) groups. Hyperglycemia was induced by streptozotocin (80 mg/kg) in the animals of diabetic and treatment groups. Before induction of diabetes in animals, animals in protective group received hydroalcoholic extract of Urtica dioica (100 mg/kg/BW /day) for five days intraperitoneally. Four weeks after induction of diabetes, animals were sacrificed and coronal sections were taken from the dorsal hippocampal formation of the right cerebral hemispheres and stained with PTAH stain. The area densities of the astrocytes were measured and compared in the three groups (p < 0.05). The number of astrocytes in DG area of controls was 17.72±6.7. The density of astrocytes increased in diabetic (24.26±9.5) in comparison with controls. The density in the nettle treated rats (23.17±5.8) was lower than diabetic rats. This study showed that the administration of U. dioica extract before induction of diabetes can not significantly help compensate for astrocytes in the dentate gyrus of treated rats.