Rosmarinus officinalis extract ameliorates cognitive deficits and hippocampal neurogenesis in mice model of diabetes mellitus

Abstract

RationaleDiabetes mellitus causes cognitive impairment and negatively affects the hippocampal integrity and neurogenesis. The impaired insulin activity and secretion contribute to the down-regulation of fibroblast growth factor which is an important stimulant of the neurogenic process. The present study elucidated the potential effects of Rosmarinus officinalis, (R. officinalis) on spatial memory and adult hippocampal neurogenesis in diabetic mice model using behavioral tests, histological and immunohistochemical analysis. Material and methodsThe male Balb/c mice were administered a high-fat diet and streptozotocin (STZ) (100 mg/kg i.p.) at 6th and 9th week of age. Following that, 36 h after second dose of STZ, 50 mg/kg R. officinalis extract was administered orally for 21 days. ResultsSTZ and a high-fat diet caused diabetes that led to the defects in learning and memory and compromised the process of hippocampal neurogenesis. Interestingly, R. officinalis improved cognitive functions and increased the expression of neurogenic markers including KI67 and NeuN, suggesting an improvement in the process of adult hippocampal neurogenesis. ConclusionsIt has been suggested that R. officinalis may act as a potential agent for the improvement of neurodegeneration and learning and memory deficits associated with diabetes. These findings warrant further investigation of the specific active constituents of R. officinalis involved in the regulation of these molecular processes to be considered as novel adjunctive therapy for diabetes mellitus-associated neurological consequences.