The current study illustrated the possible positive effects of flavonoids present in the leaves of Mespilus germanica on cognitive performance, learning and memory function in an intra-cerebroventricular streptozotocin-induced Alzheimer’s disease model in male Wistar rats. Five groups (saline-saline control, streptozotocin-saline, and streptozotocin with different doses of flavonoids, 5, 10 and 20 mg/kg) of rats were examined. Rats received different doses of Mespilus germanica flavonoids or saline over three weeks starting one day before surgery. Next, they were assessed using a learning and memory test. After subjected to the behavioral test, the animals were perfused and their brains were fixed with paraformaldehyde 4 % and the tissue was further processed. Fi nally, the density of intact neurons in the hippocampal CA1 area in all groups was investigated. The results revealed that injection of streptozotocin significantly reduced cognitive function, memory retention as well as CA1 intact neurons compared to the control group. Flavonoids extracted by Mespilus germanica considerably eradicated the negative effects of streptozotocin. Accordingly, Mespilus germanica leaf flavonoids can improve cognitive deficits resulted from injection of streptozotocins.
