Effects of peony glycosides on mice exposed to chronic unpredictable stress: Further evidence for antidepressant-like activity

Ethnopharmacology relevance: Peony, the processed root of Paeonia lactiflora Pall. (Ranunculaceae), is a component herb of many traditional formulae for the treatment of depression-like disorders. Aim of the study: The present study aimed to investigate whether the total glycosides of peony (TGP) could prevent depression induced by chronic stress. Materials and methods: Mice were subjected to an experimental setting of chronic unpredictable stress (CUS). The effect of TGP treatment on CUS-induced depression was examined by measuring behavioral and neurochemical parameters of depression and the antioxidant status of brain tissue. Results: CUS-induced depression, as indicated by a significant increase in immobility time in the tail suspension test, was associated with increases in the activities of monoamine oxidases, depletion of reduced glutathione, and an increase in malondialdehyde level, in mice brains. TGP treatment alleviated the extent of CUS-induced depression and the associated impairment of antioxidant status in the mouse brain. Conclusion: The results suggest that TGP alleviates depression induced by chronic unpredictable stress. The antidepressant-like activity of TGP is probably mediated by inhibition of monoamine oxidases and the attenuation of oxidative stress in mouse brain.