The Anti-depressive Effect of Rehmanniae Radix Preparata via Anti-inflammatory Activity

Abstract

Objectives: Rehmanniae Radix Preparata (RRP) has been used as a traditional remedy to treat gynecology and endocrine diseases. Recently, studies on antioxidant and anti-inflammatory effects of RRP have been reported, so it was judged that RRP extracts would have an anti-depressive effect.Methods: We investigated the anti-neuroinflammatory and anti-depressive effect of RRP on lipopolysaccharide (LPS)-induced depression and LPS-stimulated BV2 microglia. RRP inhibited the LPS-stimulated excessive release of nitrite in the BV2 cells. RRP also significantly inhibited the inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 in LPS-stimulated BV2 microglial cells.Results: RRP significantly suppressed the LPS-induced mitogen-activated protein kinase (MAPKs) and nuclear factor (NF)-κB activation. In addition, administration of RRP not only inhibited the immobility time in the forced swimming test (FST) but also increased the total travel distance in the open field test (OFT). Also, RRP inhibited the elevation of TNF-alpha, IL-1beta, and IL-6 in brain of LPS-injected mice.Conclusions: Considering the overall results, our study showed that RRP exhibited the anti-neuroinflammatory and anti-depressive activities via deactivation of MAPKs and NF-κB.