Effects of thymoquinone in a rat model of reserpine-induced depression

Abstract The objective of this study is to examine the antidepressant and antioxidant effects of thymoquinone (TQ) on reserpine-induced depression, and to investigate the antidepressant and antioxidant activity of combined treatment of TQ+citalopram. In total, 36 male Wistar rats were randomly divided into 6 groups: 1)control1, 2)control2, 3)reserpine, 4)reserpine+TQ 5)reserpine+citalopram and 6)reserpine+TQ+citalopram. Depression was induced by administering intraperitoneal reserpine of 0.2mg/kg/14days. For antidepressant effects, 10 mg/kg TQ and/or 10 mg/kg citalopram was administered intragastrically 30 minutes prior to the administration of reserpine. Rat behavior was examined using the Behavioral Test following the completion of treatment protocol. Total nitric oxide (NOx) levels, malondialdehyde (MDA) levels, total oxidants status (TOS), total antioxidant status (TAS) in brain cortex, plasma as well as brain cortex glutathione (GSH) and levels of plasma total sulfhydryl groups (RSH) were examined. Treatment with TQ ameliorated the reserpine-induced changes in the Behavioral Test (p<0.05). TQ treatment significantly increased dopamine (DA) and noradrenaline (NA) expressions when compared to the R group (p<0.01). Serotonin (5-HT) expression also increased significantly (p<0.05). Brain cortex and plasma TOS, MDA and NOx levels decreased, whereas TAS, GSH and RSH levels increased (p< 0.05). TQ has the ability to prevent depression induced by reserpine. The combination of TQ+citalopram can be used in the treatment of depression with a stronger antioxidant effect