Antidepressant-like activity of the aqueous extract of Allium macrostemon in mice

Aim of the study

The aim of this study was to identify the effects of water extracts of Allium macrostemon Bunge (AM-W), a traditional herb, in mice.

Materials and methods

The antidepressant-like activities of AM-W were evaluated through behavioral despair in forced swimming test and tail suspension test. To elucidate the mode of action of the antidepressant-like effects of AM-W, new born cells in the subgranular zone and the granule cell layer were analyzed by immunostaining for incorporation of 5-bromo-2-deoxyuridine (BrdU). In addition, the effects of AM-W on the expression levels of brain-derived neurotrophic factor (BDNF) were investigated by western blotting and immunohistochemistry.

Results

The administration of AM-W reduced the immobility duration in the forced swimming test and tail suspension test (100 or 200 mg/kg, P < 0.05). Sub-chronic administration of AM-W (100 or 200 mg/kg, p.o., for 14 days) increased the number of BrdU-incorporating cells. The percentage of BrdU-incorporating cells co-localized with NeuN was significantly increased after AM-W administration (100 or 200 mg/kg, P < 0.05). Moreover, the expression levels of BDNF which is reported to be associated with neurogenesis were significantly increased in the hippocampus after administration of AM-W.

Conclusions

These results suggest that AM-W may be a good antidepressant, and that its mechanism of action may be related to its positive effects on neurogenesis and BDNF release.