Mahmoud Balbaa
University of Alexandria, Egypt
Title: Role of Nigella sativa oil and antidiabetic drugs in modifying the brain insulin signaling in Streptozotocin-induced diabetic rats
Biography
Biography: Mahmoud Balbaa
Abstract
The black seeds of Nigella sativa have different biological activities and the anti-diabetic effect is among these activities. Streptozotocin (STZ) - induced diabetic rats were treated daily with NS oil (NSO) in order to study its anti-oxidative, antibrain insulin resistance, acetylcholinestrase (AChE) inhibition and anti-amyloidogenic activities. A significant decrease in the antioxidant status with peripheral and central production of pro-inflammatory mediators were observed. The brain insulin resistance and the reduced insulin signaling pathway (p-IRS/ p-AKT/p-GSK-3β) were accompanied by an increment of the
GSK-3β level, which in turn may contribute in the extensive alterations of Tau phosphorylation along with changes in PP2A level. In addition, the brain AChE was activated and associated with diminished brain glucose level and cholinergic function Furthermore, neuronal loss and elevation in Aβ-42 plaque formation were observed due to a low IDE formation and an increased expression of p53, BACE1 and APP with diminished ADAM10, SIRT1 and BDNF levels. The treatment of diabetes induced rats with NSO and the anti-diabetic drugs alone and/or in combination have the potential to suppress the oxidative stress, the pro-inflammatory mediators and amyloidogenic pathway. Moreover, it lowers the inhibitory effect of IOMe-AG538 for the insulin receptor and modifies the insulin-signaling pathway. Therefore, it prevents the neurotoxicity, amyloid plaque formation and Tau hyper-phosphorylation. These data suggest that NSO or its combined treatments with anti-diabetic drugs
have a possible protective and modifying effect of the insulin resistance in the brain through enhancing brain insulin signaling pathway.