Erxian decoction, a famous Chinese medicine formula, antagonizes corticosterone-induced injury in PC12 cells, and improves depression-like behaviours in mice

CONTEXT: In folk medicine, erxian decoction (EXD) is used to treat perimenopausal syndrome in women. It is also used clinically to treat depression, but the mechanism remains unknown. OBJECTIVES: To investigate the neuroprotective effect of EXD, and its antidepressant potential. MATERIALS AND METHODS: ICR mice were treated with EXD (0.5, 1.5 and 4.5 g/kg i.g.) and fluoxetine (6.0 mg/kg i.g.) for 10 days. On day 10 of the treatment, depression-like behaviour was induced by reserpine (2.5 mg/kg injected i.p.), and after 24 h of reserpine administration, it was assessed using the tail suspension and forced swimming tests. MTT assay, lactate dehydrogenase test, flow cytometry analysis, Hoechst staining and western blotting were used to assess the apoptosis of PC12 cells. Apoptosis proteins and neurotransmitter were tested in vitro and in vivo, respectively. RESULTS: MTT assay results showed corticosterone prevented cell growth, but EXD at concentrations of 100, 200 and 400 μg/mL restored cell viability (EC(50): 204.016 μg/mL). EXD decreased lactate dehydrogenase leakage from 63.48 to 43.60 U/L, and upregulated expression of Bcl-2 while the expression of Bax, caspase-3 and caspase-8 were decreased in vivo and in vitro. Moreover, EXD improved depression-like behaviour in mice, and 4.5 g/kg EXD treatment increased the secretion of serotonin, dopamine and norepinephrine by 67.44, 28.12 and 42.12 pg/mg, respectively, in hypothalamus compared to that of reserpine group. DISCUSSION AND CONCLUSIONS: EXD demonstrated neuroprotective effects and improved depression-like behaviour in mice. Further research should be focussed on the mechanism of the active components in EXD.