The Effect of Oleuropein on Chronic Stress-induced Anxiety: Possible Role of Oxidative Stress and Serum Corticosterone

Chronic stress is associated with the pathophysiology of various psychiatric disorders, including anxiety disorders and depression. The aim of the present study was to evaluate the effectiveness of oleuropein on anxiety in mice under chronic stress. In order to induce chronic stress (CRS), rats were subjected to immobility stress for 2 hours daily in the Restrainer device for two weeks and then to electric shock with a power of half milliampere for two minutes. Rats under chronic stress were divided into five groups, including control (receiver of drug solvent), treatment (oleuropein at doses of 7.5, 15, 30 mg/kg) and positive control (diazepam). In CRS rats, oleuropein at a dose of 30 mg/kg increased the number of entries and the time spent in the open arms of the EPM (p < 0.05). The administration of oleuropein in CRS rats at a dose of 7.5 mg/kg decreased the frequency of being on the edge in the open page test (p < 0.05). Administering different doses of oleuropein decreased lipid peroxidation and increased antioxidant capacity of brain and serum in CRS rats (p < 0.05). Oleuropein also decreased serum corticosterone in CRS rats. The effectiveness of oleuropein on anxiety behaviors in mice under chronic stress is through reducing oxidative stress.
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