Neuroprotective effects of Rosa damascena extract on learning and memory in a rat model of amyloid-β-induced...

Alzheimer's disease (AD) is an age-related progressive neurodegenerative disease, which is characterized clinically by serious impairment in memory and cognition. Current medications only slow down the dementia progression and the present treatment one-drug one-target paradigm for anti-AD treatment appears to be clinically unsuccessful. Therefore, alternative therapeutic strategies are urgently needed. With respect to multifunctional and multitargeted characteristics of Rosa damascena via its effective flavonoids, we investigated the effects of R. damascena extract on behavioral functions in a rat model of amyloid-β (A-β)-induced Alzheimer's disease.

After preparation of the methanolic extract of the R. damascena, HPLC analysis and toxicity studies, median lethal dose (LD50) and dose levels were determined. For evaluation of baseline training behavioral performance, Morris water maze and passive avoidance tests were used. A-β was injected bilaterally into CA1 area of the hippocampus. Twenty-one days after injection of A-β, the first probe trial of the behavioral tests were used to confirm learning and memory impairment. To examine the potential effects of the extract on behavioral tasks, the second probe trials were performed after one month administration of R. damasena extract.

Results showed that the R. damascena extract significantly improved the spatial and long-term memories in the extract- treated groups in a dose-dependent manner, as in the middle and high doses it had significant effect.

According to these results, we concluded that R. damascena can reverse behavioral deficits caused by A-β, and may provide a new potential option for prevention and treatment of the cognitive dysfunction in Alzheimer's disease.