Protective effect of raisin (currant) against spatial memory impairment and oxidative stress in Alzheimer disease model

Abstract

Objectives: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive pathological changes of the brain. A number of studies demonstrated compelling evidence of the importance of oxidative processes in AD pathogenesis. Raisin contains polyphenol, phenolic acid, and tannin compounds, which have antioxidant and anti-inflammatory properties. The present study was aimed to evaluate the protective effect of raisin on neurobehavioral and histological changes in rats with Alzheimer.

Methods: Animal model of AD was induced by intraperitoneal injection of aluminium chloride for 60 days (100 mg/kg body weight). During these 60 days both Alzheimer’s and control rats were given 6 g of raisin per rat. At the end of the treatment, blood was collected for biochemical assessment. We used a Morris water task and passive avoidance test to assess spatial memory.

Results: Our results showed that aluminium exposure significantly decreased the memory in the MWT and passive avoidance test, but in the raisin + AlCl₃ group, it significantly increased spatial memory in both tests. Also, Aluminium exposure significantly increased malondialdehyde (MDA) and decreased ferric reducing ability of plasma (ferric reducing/antioxidant power (FRAP)), while treatment with raisin significantly decreased MDA and increased FRAP in plasma of blood.

Discussion: Our findings showed that raisin has a neuroprotective effect and improves the spatial memory in AD animal models.

Keywords:

• Alzheimer’s disease
• Antioxidant
• Aluminium chloride
• Raisin
• Spatial memory