Ameliorative Effect of Silymarin on Scopolamine-induced Dementia in Rats

  • Salma A. A. El-Marasy Pharmacology Department, National Research Centre, Giza
  • Reham M. Abd-Elsalam Pathology Department, Faculty of Veterinary Medicine, Giza, Cairo University, Cairo
  • Omar A. Ahmed-Farid Physiology Department, National Organization for Drug Control and Research, Giza
Keywords: Silymarin, Scopolamine, Object recognition test, Dementia, Donepezil, Rats


AIM: This study aims to elucidate the possible ameliorative effect of silymarin on scopolamine-induced dementia using the object recognition test (ORT) in rats.

METHODS: The study was extended to demonstrate the role of cholinergic activity, oxidative stress, neuroinflammation, brain neurotransmitters and histopathological changes in the anti-amnestic effect of silymarin in demented rats. Wistar rats were pre-treated with silymarin (200, 400, 800 mg/kg) or donepezil (10 mg/kg) orally for 14 consecutive days. Dementia was induced after the last drug administration by a single intraperitoneal dose of scopolamine (16 mg/kg). Then behavioural, biochemical, histopathological, and immunohistochemical analyses were then performed.

RESULTS: Rats pre-treated with silymarin counteracted scopolamine-induced non-spatial working memory impairment in the ORT and decreased acetylcholinesterase (AChE) activity, reduced malondialdehyde (MDA), elevated reduced glutathione (GSH), restored gamma-aminobutyric acid (GABA) and dopamine (DA) contents in the cortical and hippocampal brain homogenates. Silymarin reversed scopolamine-induced histopathological changes. Immunohistochemical analysis showed that silymarin mitigated protein expression of the glial fibrillary acidic protein (GFAP) and nuclear factor kappa-B (NF-κB) in the brain cortex and hippocampus. All these effects of silymarin were similar to that of the standard anti-amnestic drug, donepezil.

CONCLUSION: This study reveals that the ameliorative effect of silymarin on scopolamine-induced dementia in rats using the ORT maybe in part mediated by, enhancement of cholinergic activity, anti-oxidant and anti-inflammatory activities as well as mitigation in brain neurotransmitters and histopathological changes.


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How to Cite
A. El-Marasy SA, Abd-Elsalam RM, Ahmed-Farid OA. Ameliorative Effect of Silymarin on Scopolamine-induced Dementia in Rats. Open Access Maced J Med Sci [Internet]. 2018Jul.17 [cited 2020Nov.27];6(7):1215-24. Available from:
A - Basic Science