Neuroprotective effects of constituents of the oriental crude drugs, Rhodiola sacra, R. sachalinensis and Tokaku-joki-to, against beta-amyloid toxicity, oxidative stress and apoptosis - Mook-Jung,I.; Kim,H.; Fan,W.; Tezuka,Y.; Kadota,S.; Nishizo,H. (Biol Pharm Bull, 2002)