Bee honey attenuates the memory loss and depression like behavior that induced by chronic unpredictable mild stress in rat

Background and Aim : Stress is an organism s response to internal or external stimulation. This natural response may get the living system ready to preserve its homeostasis. Chronic and higher levels of stress play a key role in the induction of various clinical disorders by altering the HPA axis and antioxidant defenses. Cognitive processes, such as learning and memory, are affected by chronic stress. Chronic unpredictable mild stress (CUMS) induces hippocampal oxidative stress which mainly involved in neurodegenerative disorders such as Alzheimer s disease. Bee honey is a natural and accessible product that has exhibited antioxidant capacity. Our study investigated the effects of bee honey pretreatment on two stress comorbidities, memory deficits, and depressive-like behavior, by examining the changes with Morris water maze memory test and sucrose performance tests in the CUMS.Methods : 1o days before CUMS induction, honey (dose 0.2 and 2 g/kg, daily, orally) was delivered to the rats and continued until euthanasia. Animals were exposed to CUMS for 28 days. After this duration, the Morris water maze memory test and sucrose performance test was performed.Results : Escape latency became progressively shorter across training sessions. A further analysis revealed that there are significant differences in escape latency at day 2 and 3 (p < 0.01, 0.05 respectively) between CUS and the control group, while honey administration (2 g/kg) significantly improved such deficiencies (p < 0.05 at day 2, 4 and p<0.01 at day 3 compare to stress group). To determine the degree of memory, on the fifth day the time that the animals spent in the target quadrant was recorded. Rats exposed to CUS spent less time in the target quadrant compared to the control animals, while treatment with honey (2 g/kg) reversed these changes (p<0.05). Also, chronic treatment with honey at both doses significantly increased the percentage of sucrose consumption, as compared to the stressed rats (P<0.001)Conclusion : Our results showed that pretreatment with honey in the chronic unpredictable mild stress conditions decreased the learning and memory loss and also has a beneficial effect on depression-like behavior.

Keywords:

Bee honey , learning and memory , Morris water maze , sucrose performance