Ninjinyoeito exerts an antidepressant‐like effect by enhancing the central noradrenergic system

Abstract

Ninjinyoeito (NYT) is a Kampo medicine prescribed for patients with decreased mental and physical energy. Clinical studies demonstrate that NYT ameliorates depressive symptoms in patients with various diseases. However, the underlying therapeutic mechanisms of action remain unclear. The monoaminergic system has been implicated in the neuropathology of depression. Using immobility in the tail suspension test to evaluate depression‐like behavior, we aimed to examine the effects of NYT and the involvement of the α1‐adrenoceptor and serotonin (5‐HT)1A receptor in its mechanism of action.