Background:  Schizophrenia is a chronic debilitating psychiatric disorder affecting 1% of the population worldwide. As for key role of free radicals in the development of this disease and that Quince leaf is a natural source of antioxidant substances, this study was aimed to evaluate the protective effects of Quince leaf extract on locomotor activity and anxiety-like behaviors by an intraperitoneal injection of ketamine in male mice in a ketamine model of schizophrenia.

Materials and Methods: In the experimental research, male adult mice were divided into six groups including: control, Sham (received water orally and saline intraperitoneally), psychosis group (received 10 mg/kg/day ketamine i.p. for 10 days) and treated psychosis groups (received 50, 100 and 150 mg/kg/day). Treated groups received hydroalcoholic Quince leaf extract orally for 3 weeks before injection of ketamine. Extract gavages continue for 5 days after the last ketamine injection. Locomotor activity and anxiety-like behavioral changes were measured in the open-field test.

Results: The results showed that chronic administration of ketamine increases horizontal locomotor activity and anxiety like behaviors (p≤0.001) and pretreatment of Quince leaf extract effectively decreases horizontal locomotor activity (p<0.001) and increases duration that spends in middle area of Open field (p<0.01) and vertical ocomotor activity(p<0.001).

Conclusion: The results of this research showed that chronic administration of Quince leaf extract improves locomotor disorder and induced anxiety-like behaviors by having antioxidant properties in a ketamine model of schizophrenia.