Zingiber officinale and Alzheimer’s Disease: Evidences and Mechanisms

Abstract

This study was planned to assess the efficacy of ginger rhizomes extract and ginger rhizomes oil in the regression of Alzheimer’s disease (AD) induced in a rat model in an attempt to explore their mode of action against this neurodegenerative disease. Seventy male Wistar rats were divided into seven groups; G(1): Negative control group (con), G(2): Ginger extract control group orally administered 100 mg/kg of ginger rhizomes extract (GE), G(3): Ginger oil control group orally administered 100 mg/kg of ginger rhizomes oil (GO), G(4): Positive control group orally received aluminum chloride in a dose of 17 mg/kg to induce AD (AD), G(5):Ginger extract treated group orally administered 100 mg/kg of ginger rhizomes extract after induction of AD (AD+GE), G(6): Ginger oil treated group orally administered 100 mg/kg of ginger rhizomes oil after induction of AD (AD+GO) and G(7): Memantine treated group orally administered 10 mg/kg of memantine after induction of AD (AD+M). Brain acetylcholinesterase (AchE) activity was estimated colorimetrically. Brain acetylcholine (Ach), nuclear factor kappa B (NF-κB), caspase3 and p53 levels were determined using ELISA technique. Immunohistochemical procedure was used for detection of brain acetylcholintransferase (AchT) activity. Additionally, histopathological investigation of brain tissue sections was carried out. In comparison with the negative control group, AD group recorded significant increase in the brain values of AchE, NF-κB, caspase3 and p53 in concomitant with a significant decrease in the brain level of Ach. Moreover, immunohistochemical finding revealed negative reaction concerning AchT activity in the AD group. Furthermore, histopathological investigation of brain tissue sections of rats in AD group showed the formation of amyloid plaques.In contrast, the treatment of AD group with GE or GO resulted in an improvement in the most studied biochemical parameters as indicated by the decreased brain values of AchE, NF-κB, caspase3 and p53 accompanied with significant increase in the brain level of Ach as compared to an untreated AD group. Immunohistochemical results showed positive reaction regarding AchT activity in the AD groups treated with either GE or GO. Moreover, AD groups treated with GE or GO showed great improvement in the brain morphological structure with the disappearance of the most amyloid plaques. This current study indicated that GE and GO significantly ameliorates the neuroinflammation and apoptosis characterizing Alzheimer’s disease in the experimental model due to their anticholinesterase activity and antiapoptotic potential besides the anti-inflammatory effect.