“…("Yuanzhi" in Chinese) is a well-known traditional Chinese medicine (TCM) herb, which was first documented in Shen Nong Ben Cao Jing, and its dried root has for a long time been traditionally used to treat memory loss in Asian countries (Howes and Houghton, 2003;Kwon et al, 2004;Adams et al, 2007). Recent pharmacological studies have shown that P. tenuifolia could improve memory impairment caused by scopolamine, stress, glutamate, and Aβ, and promote neuronal proliferation in normal brains (Chung et al, 2002;Lin et al, 2012;Li et al, 2014). Polygalasaponins, such as polygalasaponin B, F, G, and XXXII, are the main components responsible for the action of P. tenuifolia and have been shown to improve cognitive impairment in AD effectively (Ikeya et al, 2004;Xu et al, 2009;Wu et al, 2014).…”