Effect of ascorbic acid microinjection on spatial memory and oxidative stress in an experimental model of Alzheimer’s disease induced by streptozotocin

Alzheimer’s disease (AD) is characterized by loss of memory and an impairment of multiple cognitive functions. One of the factors that play an effective role in the pathogenesis of Alzheimer’s disease and memory impairment is oxidative stress. Ascorbic acid has high antioxidant activity and is involved in memory and learning. In this study we assessed the impact of ascorbic acid on the memory improvement in an animal model of Alzheimer’s disease induced by streptozotocin in rats.

Streptozotocin was injected into cerebral lateral ventricles of rats bilaterally. After two weeks, ascorbic acid (5mg/kg) was microinjected into brain lateral ventricles for five days.  The Morris water maze test was then performed to examine spatial memory of rats. At the end of behavioral test, hippocampal antioxidant activity was measured.

Streptozotocin significantly impaired spatial memory of rats compared to control group (p < 0.001). The level of oxidative stress significantly increased by streptozotocin compared to control group (p < 0.001). Ascorbic acid improved spatial memory and decreased the level of oxidative stress in streptozotocin-received rats (p < 0.001).

It seems that ascorbic acid improves memory impairment of streptozotocin-received rats by diminishing the oxidative stress.