Investigation of effects of pomegranate (Punica granatum L.)? flowers on oxidative damages in the brain and cognitive functions of experimental diabetic rats

Diabetes mellitus are termed as `chronic hyperglicemia? leading to disturbances in carbonhydrate, lipid or protein metabolism as consequences of inefficiency of insulin, insufficiency of insulin release or both. Oxidative stress induced during the course of diabetes mellitus leads to damages in various tissues and organs. Due to the damages to central nervous system, diabetes mellitus affects cognitive functions. Therefore, for the treatment of diabetes mellitus, in addition to antidiabetics, antioxidants are advised to be used to cope with oxidative stress. The ethnobotanic investigation carried out in Turkey showed that use of plants with antioxidant properties decrease the severity of the symptom of diabetes mellitus. Recently, it has been reported that flowers of pomegranata have antioxidant properties. In the current study, the role of oxidative stress in the formation of damages associated with diabetes mellitus and antioxidant ability of pomegranata?s flowers to cope with the oxidative stress were investigated.In the current study, rats were divided into five groups: diabetes (STZ), STZ + the flowers of pomegranata I (PGF-I) (300 mg/kg/day), STZ + the flowers of pomegranata II (PGF-II) (400 mg/kg/day), STZ + the flowers of pomegranata III (PGF-III) (500 mg/kg/day).The findings from Morris Water Maze and Probe tests in diabetes mellitus, control and flowers of pomegranata receiving animal groups showed that the animals in STZ group had disturbances in learning and memory performances compared to the other groups. The group that showed best performances in learning and memory tests closest to those of control animals among other experimental groups were STZ + PGF III group. There were no significant difference between control and STZ + PGF III group (p<0.05).In diabetus mellitus group, the level of GSH was significantly lower (p<0.05). Whereas, the levels of LPO and GFAP expression were higher (p<0.05). There were no significant difference between the levels of GFAP in STZ + PGF-III and control. The level of GFAP expression were higher in STZ group compared to those of the other groups. The level of GSH in STZ +PGF-I, STZ +PGF-II and STZ +PGF-III groups were significantly higher (p<0.05). The levels of LPO in STZ +PGF-I, STZ +PGF-II and STZ +PGF-III groups were significantly lower compared to that of STZ group.These findings show that flowers of pomegranata may have considerable contribution to treatment of diabetes mellitus and prevention from the damages induced by diabetes mellitus. Particularly, the data obtained by the current scientific study endow a scientific point of view to the commonly used alternative medicine about the importance of supportive curing approaches towards the prevention of diabetic complications.Keywords: Cognitive Functions, Diabetes Mellitus, Flowers of Pomegranata, GFAP, Oxidative Stress