Depression exists with high prevalence and heavy disease burden. Stress events play a key role in the occurrence of depression, but the pathological mechanism has not been fully clarified by reason of the complexity and heterogeneity. In recent years, neuroinflammation as a pathological mechanism of depression has received extensive attention. The activated microglia is regarded as the marker of neuroinflammation, which is an important link of stress-induced depression. Stress might induce microglia activation through pattern recognition receptors(PRR), intestinal flora, hypothalamic-pituitary-adrenal(HPA) axis, and other pathways. Cross-talk between impaired microglia function and neurobiological factors such as inflammatory cytokines, serotonin metabolism, and neuroplasticity may lead to depression. At present, a large number of studies have proved that traditional Chinese medicine(TCM) plays an anti-depressive role by inhibiting microglia activation, which may be potential treatment strategies for depressive disorder. This paper reviewed the research progress of stress-induced microglia activation in depression and summarized the mechanism of TCM against depression with regard to microglia, hoping to provide experimental evidence and consideration for TCM against depression through microglia.
Keywords: depression; immunity inflammation; microglia; review; stress; traditional Chinese medicine.