DISCUSSION
Panax ginseng C. A. Mayer (Araliceae) has been used as a traditional herbal medicine in many oriental countries.30) KRG made by steaming and drying process of ginseng is known to gain some beneficial properties through the chemical transformation of active components of ginseng during the steaming process.31) The extract obtained from KRG has been reported to exhibit a variety of pharmacological actions, suggesting that it may be beneficial for several types of disorders including cancer and diabetes.14–17) In addition, KRG extract has been shown to protect SK-N-SH cells19) and hippocampal cells18) against H2O2-induced oxidative stress and kainate-induced neurotoxicity, respectively, implying its additional beneficial actions in the CNS. We observed in this study that KRG extract inhibited glutamate- or NMDA-induced excitotoxicity as well as Aβ-induced neurotoxicity in primary cultured rat cortical cells. Based on our findings, the neuroprotective action exerted by KRG extract is associated with inhibition of ROS generation and apoptotic cell death caused by these insults.