Molecular Mechanisms Involved in the Ameliorative Effect of Silymarin against Experimentally-Induced Alzheimer Disease in Rats

Abstract

Background:Alzheimer disease (AD), One of the commonest chronic neurodegenerative disorders that worsens overtime. Our current study examined the molecular mechanism that mediate the effect of silymarin on aluminum induced Alzheimer disease. Methods:experimental animals were divided into three groups; control group, Alzheimer rat-group and silymarin-treated group.  After 6 weeks of treatment, the Morris water maze (MWM) test for memory assessment and histopathological examination of rat brains were done.

The amyloid beta precursor protein (AβPP) expression,beta-siteamyloid precursor protein cleaving enzyme (BACE-1) and (NOS-1) or the neuronal isoform of nitric oxide synthase mRNAs was performed. Measurement of oxidative stress related markers in brain tissues were determined. Results:Our results with the rats treated

with silymarin showed attenuated aluminum induced Alzheimer disease as indicated by MWM test. Such effect was associated with decrease in AβPP, beta secretase and NOS-1 expression, attenuation of brain oxidative stress markers, and improvement of histopathological changes. Conclusion: The study concluded that the molecular biological mechanisms of the neuroprotective effects mediated by silymarin in Alzheimer disease (AD) were through down regulation of AβPP, beta secretase and NOS-1 expression.