Ginsenosides or panaxosides are a class of steroid glycosides, and triterpene saponins, found exclusively in the plant genus Panax (ginseng). Ginsenosides have been the target of research, as they are viewed as the active compounds behind the claims of ginseng's efficacy. These are often split into two groups: the Rb1 group (characterized by the protopanaxadiol presence : Rb1, Rb2, Rc and Rd) and the Rg1 group (protopanaxatriol: Rg1, Re, Rf, and Rg2).Appears to be most abundant in Panax ginseng (Chinese/Korean Ginseng). Improves spatial learning and increase hippocampal synaptophysin level in mice, plus estrogen-like activity (which could account for the boosting of "yin" theory). A recent study demonstrated that Rg1, isolated from Panax ginseng is able to attenuate the oxidative stress in the liver of exhaustive exercised rats.