The effect of oleuropein on passive avoidance memory in colchicine-induced rat model of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease along with learning and memory disorders. Oleuropein is a phenolic compound with antioxidant and neuroprotective properties that reduces oxidative stress and improves cognitive function. The purpose of this study was to investigate the effect of oleuropein pretreatment on the colchicine- induced cognitive dysfunction using passive avoidance learning.
Adult male rats (200-250 g) were used in this study. Oleuropein (10 and 20 mg/kg, p.o.) was used for a period of 10 days prior to colchicine administration. On the tenth day of administration, the rats were bilaterally cannulated at the CA1 area. Colchicine (15 μg/rat) was bilaterally administered into CA1 area of the hippocampus. After one week of recovery, then their learning and memory levels were investigated through passive avoidance learning test. For assessment of retention memory after 24 hours, the interval between the placement in the light chamber and the entry into the dark chamber was measured as step through latency. Furthermore, the total time spent in the dark chamber was also measured.
Administration of colchicine reduced the step through latency and augmented the time spent in the dark chamber. Administration of oleuropein (10 and 20 mg/kg) prior to colchicine (15 µg/rat) improved colchicine-induced cognitive impairment.
The results showed that oral administration of oleuropein improves learning and memory impairment induced by colchicine.