Cinnamomum cassia: an implication of serotonin reuptake inhibition in animal models of depression.

The aim of the study was to explore the traditional use of Cinnamomum cassia against depression. The standardised methanolic extract of the bark of C. cassia was evaluated for antidepressant activity using various behavioural tests, i.e. tail suspension test (TST), forced swim test (FST) and locomotor activity test. The serotonergic and noradrenergic modulation was assessed using 5-hydroxytryptophan (5-HTP)-induced head twitches and yohimbine potentiation tests, respectively. The fluoxetine and phenelzine were used as positive controls in the study. The C. cassia extract significantly decreased the immobility time in TST (maximum effective dose tested was 50 mg/kg) while no effect was observed in FST and locomotor activity test. The extract significantly increased the 5-HTP-induced head twitches while yohimbine-induced lethality remained unaltered. The aforementioned results are similar to that caused by fluoxetine. The standardised methanolic extract of C. cassia demonstrated antidepressant activity that can be attributed to rise in serotonin levels.