Effect of Ninjin’yoeito on Lipopolysaccharide-Induced Depressive-Like Behavior and Glial Activation in the Hippocampus

Depression is one of the most common mental disorders. Glial cells have been reported to play a role in the pathogenesis of depression. Meanwhile, Ninjin’yoeito (NYT), a Kampo medicine, is a multi-component drug that was reported to improve depressive symptoms in patient and animal models. In addition, some of its components have an effect on glial cells. However, the mechanism remains unclear. The study’s aim was to investigate the effect of NYT in recovering depressive-like behavior and glial pathological changes in the hippocampus induced by lipopolysaccharide. Here, we showed that NYT improved the forced swim test performances of the rat. Furthermore, NYT also inhibited microglial activation in the hippocampus, but the results were different in astrocytes. These results suggest that NYT alleviates depressive-like behavior, and the effect may be associated with the attenuation of glial cell activation.