Neuroprotective effect of morin against unpredictable chronic mild stress induced oxidative stress and behavioural deficits in Wistar rats

Morin is a bioflavonoid widely found in fruits and vegetables, which possesses the protective activity to various neurological diseases. An earlier report showed that the administration of morin had antidepressant-like effect against acute stress conditions. Acute stress induces only transient changes in the brain while the prolonged stress increases vulnerability to mental disorders. To better understand its anti depressive activity, we explored the neuroprotective role of morin against unpredictable chronic mild stress (UCMS) induced rats. Male Wistar rats were randomized and grouped into control, UCMS exposed (different stressors) UCMS and morin (30 & 60 mg/kg) co-treated and morin alone treated (60 mg/kg). Morris water maze test (MWMT) and sucrose preference test (SPT) were employed to study the effect of morin on learning, memory and anhedonia of rats. In addition, the levels of thiobarbituric acid (TBARS) and reduced glutathione (GSH) and the activities of super oxide dismutase (SOD), catalase and glutathione peroxidase (GPx) were estimated. Behavior studies indicated that morin treatment significantly increased the memory and sucrose intake as shown by MWMT and SPT respectively. Moreover, it exhibited the antioxidant activity by reducing the amount of lipid peroxidation products (TBARS) and GSH and activities of enzymatic antioxidants in UCMS rats. Our experiment suggested that the antidepressant-like actions of morin could be due to its potent antioxidant property.