Effect of Oleuropein on the Gene Expression of Brain-derived Neurotrophic Factor, Stress Oxidative, and Spatial Memory Impairment Caused by Scopolamine in Male Rats

Oleuropein is an important phenolic compound found in olive leaves that has important pharmacological functions in the central nervous system and neuroprotective effects in vitro and in vivo conditions. This study was conducted to investigate the improving effects of oleuropein on the formation of scopolamine-induced spatial memory.

The statistical population of this study consisted of 35 male rats, which were randomly divided into five groups (n=7 each). The control group received normal saline, the scopolamine group was subjected to intraperitoneal scopolamine at a dose of 1 mg/kg for 3 weeks, and the treatment groups were administered oleuropein in three doses of 5, 10, and 20 mg/kg. At the end of the behavioral tests, blood samples and brain tissues (hippocampus) of the animals were removed for biochemical and molecular tests.

Based on the results, scopolamine significantly decreased spatial memory, whereas the injections of different doses of oleuropein improved spatial memory and learning. On the other hand, scopolamine decreased the antioxidant capacity of the serum and hippocampus, while oleuropein significantly increased these values. Our results also revealed that treatment of rats with oleuropein significantly increased the expression of brain-derived neurotrophic factor gene in the hippocampus.

According to the results of this study, oleuropein can be a neuropharmacological agent against scopolamine-induced amnesia.