The Oleuropein Effect on Neurotrophic Factor Expression Level in Hippocampal Tissue and Memory Defect Induced by Morphine in Male Rats: An Experimental Study

Taking morphine can cause damage to the hippocampus. Oleuropein has a protective effect on brain neurons. The aim of this study was to determine the effect of oleuropein on brain-derived neurotrophic factor (BDNF) protein expression level in hippocampal tissue and memory defect induced by morphine in rats.

In this experimental study, 40 male Wistar rats were used. The animals were divided into five groups (n=8) including control/saline group (receiving saline intraperitoneally for four weeks), morphine group (receiving 40 mg/kg morphine daily subcutaneously for four weeks) and morphine + Oleuropein groups (receiving doses of 5, 15, and 30 mg/kg oleuropein + morphine by intraperitoneal injection for 4 weeks). At the end, the animals’ working memory was evaluated using the Y-maze behavior measurement test. The hippocampal BDNF protein expression level was measured using the ELISA method. One-way ANOVA test with Tukey’s post-test was used to analyze the data.

Intraperitoneal injection of oleuropein at a dose of 30 mg/kg in the rats receiving morphine significantly improved the memory function (p<0.01) and increased the BDNF protein expression level (p<0.05) compared to the morphine treated groups.

Oleuropein may increase the BDNF protein expression level in the hippocampal tissue and improves the memory defect induced by morphine in rats.