Antidepressant-like effects of albiflorin extracted from Radix paeoniae Alba.

ETHNOPHARMACOLOGY RELEVANCE: Albiflorin, a monoterpene glycoside, is a main component of Radix paeoniae Alba, which could be a Chinese herbal medicine used in the treatment of psychiatric disorders. However, the exact role of albiflorin in depression is poorly understood. AIM OF THE STUDY: The current study aimed to evaluate the antidepressant effect of albiflorin in mice and rats, and the possible mechanism was also determined. MATERIALS AND METHODS: The antidepressant-like effects of albiflorin was determined by using animal models of depression including forced swim and tail suspension tests in mice and chronic unpredictable stress (CUS) in rats. The acting mechanism was explored by determining the effect of albiflorin on the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus by western blot and the levels of monoamine in the hippocampus by HPLC. RESULTS: Our results showed that 7 days treatment with albiflorin significantly decreased immobility time in the forced swimming test (FST) and the tail suspension test (TST) at doses of 3.5, 7.0 and 14.0mg/kg without alter the locomotor activity in mice. Moreover, western blot analysis showed that albiflorin could increase the expression of BDNF in the hippocampus. We further exposed rats to a chronic unpredictable stress (CUS) protocol for a period of 35d to induce depressive-like behaviors. We found that chronic treatment with albiflorin, at doses of 7.0 and 14.0mg (i.g., once daily for 35d), restored the sucrose preference in CUS rats. In the open-field test, albiflorin significantly increased the number of crossings and rearings in the CUS rats at three doses. Moreover, chronic treatment with albiflorin up-regulated the hippocampal BDNF expression levels and the hippocampal 5-HT, 5-HIAA, and NA levels. CONCLUSION: Albiflorin produced significant antidepressant-like effects, which were closely related to the hippocampal 5-HT/NE increase and BDNF expression. Our data indicated that albiflorin could be a potential anti-depressant drug.