A Herbal Mixture of Sesami Semen Nigrum and Longan Arillus Induces Neurite Outgrowth in Cultured Neurons and Shows Anti-Depression in Chronic Mild Stress-Induced Rats

Medicinal food homology is referring to a group of food itself being considered as herbal medicine without a boundary of usage. Under the guidance of this food/medicine principle, the current study aims to develop anti-depressant from this food/medicine catalog. The herbal mixture of Sesami Semen Nigrum and Longan Arillus was evaluated in cultured PC12 rat pheochromocytoma cells, rat primary cortical neurons, and in chronic mild stress (CMS)-induced depressive rat model. The combination of two ethanolic extracts of Sesami Semen Nigrum and Longan Arillus in 1 : 1 ratio mimicked the function of nerve growth factor (NGF) and synergistically induced neurite outgrowth of PC12 cells. Besides, the expression and phosphorylation of tropomyosin receptor kinase A (TrkA) of the cultured cells were also elevated. This neurotrophic activity of herbal mixture was further supported by the increased expressions of biomarkers for neurogenesis and synaptogenesis in cortical neurons. Moreover, the depressed rats were soothed by the intake of herbal mixture, showing improved performance in behavior tests, as well as reversed levels of neurotransmitters and neurotrophic factors. Our results provide a new way to make full use of the current food/medicine resources, as to accelerate the development of therapeutics for depression.