Objective: Psychosocial stress has been implicated in the genesis of psychiatric disorders such as memory deficits,depression,anxiety and addiction.Aqueous leaf extract of Cymbopogon citratus (CYC) otherwise known as lemongrass tea has antidepressant,anxiolytic and anti-amnesic effects in rodents.This study was designed to evaluate if C citratus could reverse the neurobehavioral and biochemical derangements induced by social defeat stress (SDS) in the resident/intruder paradigm.Methods: Intruder male mice were divided into five groups (n =7): group 1 received saline (10 mL/kg,p.o.;non-stress control),group 2 also received saline (10 mL/kg,p.o.;SDS control) while groups 3-5 had C.citratus (50,100 and 200 mg/kg,p.o.) daily for 14 d.The SDS was carried out 30 min after each treatment from day 7 to day 14 by exposing each intruder mouse in groups 2-5 to a 10 min confrontation in the home cage of an aggressive resident counterpart.The neurobehavioral features (spontaneous motor activity-SMA,anxiety,memory,social avoidance and depression were then evaluated.The concentrations of nitrite,malondialdehyde and glutathione as well as acetylcholinesterase activity in the brain tissues were also determined.Results: C.citratus (50,100 and 200 mg/kg) attenuated hypolocomotion,heightened anxiety,depressive-like symptom,memory deficit and social avoidance induced by SDS.The altered levels of oxidative stress and acetyl-cholinesterase in SDS-mice were positively modulated by C.citratus.Conclusion: The results of this study suggest that C.citratus might mitigate psychosocial stress-induced neurologic diseases in susceptible individuals.