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.

We tested the constituents of two Rhodiola plants, Rhodiola sacra S. H. Fu and R. sachalinensis A. BOR, and an Oriental crude drug, Tokaku-joki-to, for their neuroprotective effects. Of the 58 compounds tested, six had considerable protective effects against beta-amyloid-induced death of B103 neuronal cells in vitro. These six compounds also showed protective effects against staurosporine-induced cell death, and two of the six compounds protected neurons from H2O2-induced cell death. These results suggest that some of the tested compounds protect neurons from beta-amyloid toxicity based on antiapoptotic and antioxidative activity.