Effects of Pure Flavonoid of Medlar Leaves on Passive Avoidance Learning and Memory In Alzheimer Model of Ovariectomized Rats

Ovariectomy and estrogen removal by inducing metabolic syndrome reduce learning and memory and increase the likelihood of developing Alzheimer’s disease(AD). AD is a progressive neurological disorder with no definite cure. Polyphenols have shown important effects in preventing neurological disorders, due to antioxidant properties.
The goal of this study was to investigate the effect of pure flavonoid of medlar leaves, on STZ-induced memory impairment in ovariectomized rats.
In this experimental study, forty eight female Wistar rats weighing 200-250 g, were divided into six groups including: SHAM, OVX, OVX䤶(3mg/kg), OVX䠂, OVX䤶縔, OVX䤶 䠂. At the initial of the experiment, rats were ovariectomized, and after three weeks they were cannulated using stereotaxic apparatus. Intracerebroventricular injection of STZ(3mg/kg,2times) was used to induce memory impairment. Rats received pure flavonoid(10mg/kg, Intraperitoneal), in the STZ injection day for 21 days. All rats were tested for passive avoidance learning and memory in the shuttle box. Latency to enter to dark compartment and total time spent in that compartment were used as passive avoidance memory indices.
There was no significant difference in the acquisition and retrieval of memory between OVX ,SHAM groups(p=0.873). ICV injection of STZ significantly decreased latency to enter to dark compartment and increased total time spent in that compartment(p=0.001). The OVX䤶縔 group receiving pure flavonoid of medlar showed a significant improvement in passive avoidance learning and memory, compared with OVX䤶繈 group(P=0.001( .
ICV injection of STZ disturbs passive avoidance learning and memory and treatment with pure flavonoid of medlar improves memory impairment induced by ICV injection of STZ.