Involvement of FGF-2 modulation in the antidepressant-like effects of liquiritin in mice.

ABSTRACT

It has been reported that liquiritin produced an antidepressant-like effect in rodents. However, little information is known regarding its antidepressant activity with the regulation of fibroblast growth factor 2 (FGF-2), a protein maintaining development and maturation of the nervous central system. Therefore, the aim of the present study was to investigate the underlying FGF-2 modulation involved in the antidepressant-like effects of liquiritin. In the present study, mice were orally administrated with liquiritin for 7 days prior to LPS injection. The depressive-like behaviors, levels of FGF-2, number of Iba1 positive cells, expression of proinflammatory cytokines and density of dendritic spines were evaluated. The results showed that liquiritin significantly ameliorated the depressive-like behaviors in mice response to LPS injection. Liquiritin reversed the reduction of FGF-2 levels in the hippocampus of LPS induced mice. In addition, the microglial activation caused by LPS was attenuated by liquiritin, in accordance with downregulation in mRNA levels of proinflammatory cytokines. Moreover, liquiritin also increased the density of dendritic spines in the hippocampus, which was suppressed by LPS. In conclusion, our findings demonstrated that liquiritin exerted the antidepressant-like effects in LPS-induced depression through FGF-2 enhancement by inhibiting neuroinflammation and maintaining synaptogenesis.