Table 1.

The components and possible mechanisms on depression of four Chinese herbal medicines.

	Components	Possible antidepressant mechanism (modern medicine theory)	Possible antidepressant mechanism (traditional Chinese medicine theory)
Xiao Yao San	BaiShao (Paeonia lactiflora Pall.), ChaiHu (Bupleurum chinense DC), BaiZhu (rhizome of Atractylodes macrocephala Koidz.), DangGui (Angelica sinensis [Oliv.] Diels), GanJiang (Zingiber officinale Rosc.), FuLing (Pori cocos [Schw.] Wolf.), GanCao (Glycyrrhiza uralensis Fisch.), BoHe (Mentha haplocalyx Briq.).	Increase 5-HT and DA levels, inhibit hyperactivity of the HPA axis, and upregulate BDNF.	Harmonize the liver and spleen, sooth liver and relieve depression, nourish blood, and invigorate the spleen.
Shuganjieyu capsules	GuanYeLianQiao (Hypericum perforatum L.), CiWuJia (Acanthopanax senticosus [Rupr. Maxim.]).	Increase 5-HT, NE, and DA levels, increase expression of BDNF, and promote neurogenesis.	Sooth the liver and relieve depression, invigorate the spleen, and tranquilize the mind.
Chaihu Shugan San	CaiHu (Bupleurum chinense DC.), ChenPi (Citrus reticulata Blanco), BaiShao (Paeonia lactiflora Pall.), ZhiKe (Citrus aurantium L.), XiangFu (Cyperus rotundus L.), ChuanXiong (Ligusticum chuanxiong Hort.), GanCao (Glycyrrhiza uralensis Fisch.).	Increase expression of BDNF, neuroprotective effects, and anti-inflammatory.	Dredge the liver to regulate Qi, remove stasis, promote blood circulation, and pain relief.
Ganmai Dazao decoction	GanCao (Glycyrrhiza uralensis Fisch.), XiaoMai (Triticum aestivum L.), DaZao (Ziziphus jujube Mill.)	Increase the activity and level 5-HT and NE, regulate HPA axis elevation, and neuroprotective effects to reduce stress impairments to synapses.	Nourish the heart and tranquilize the mind, harmonize the function of the middle jiao, and alleviate pain.

5-HT, serotonin; DA, dopamine; NE, norepinephrine; HPA, hypothalamic-pituitary-adrenal; BDNF, brain-derived neurotrophic factor.