About this Journal Submit a Manuscript Table of Contents
Evidence-Based Complementary and Alternative Medicine
Volume 2012 (2012), Article ID 479016, 10 pages
http://dx.doi.org/10.1155/2012/479016
Research Article

Red Ginseng Extract Attenuates Kainate-Induced Excitotoxicity by Antioxidative Effects

1Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea
2College of Pharmacy, Chungbuk National University, Cheongju 361-763, Republic of Korea
3College of Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea
4College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea

Received 17 April 2012; Revised 11 September 2012; Accepted 20 September 2012

Academic Editor: Paul Siu-Po Ip

Copyright © 2012 Jin-Yi Han et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study investigated the neuroprotective activity of red ginseng extract (RGE, Panax ginseng, C. A. Meyer) against kainic acid- (KA-) induced excitotoxicity in vitro and in vivo. In hippocampal cells, RGE inhibited KA-induced excitotoxicity in a dose-dependent manner as measured by the MTT assay. To study the possible mechanisms of the RGE-mediated neuroprotective effect against KA-induced cytotoxicity, we examined the levels of intracellular reactive oxygen species (ROS) and [Ca2+]i in cultured hippocampal neurons and found that RGE treatment dose-dependently inhibited intracellular ROS and [Ca2+]i elevation. Oral administration of RGE (30 and 200 mg/kg) in mice decreased the malondialdehyde (MDA) level induced by KA injection (30 mg/kg, i.p.). In addition, similar results were obtained after pretreatment with the radical scavengers Trolox and N, N′-dimethylthiourea (DMTU). Finally, after confirming the protective effect of RGE on hippocampal brain-derived neurotropic factor (BDNF) protein levels, we found that RGE is active compounds mixture in KA-induced hippocampal mossy-fiber function improvement. Furthermore, RGE eliminated 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and the IC50 was approximately 10 mg/ml. The reductive activity of RGE, as measured by reaction with hydroxyl radical (OH), was similar to trolox. The second-order rate constant of RGE for OH was 3.5–  M−1 S−1. Therefore, these results indicate that RGE possesses radical reduction activity and alleviates KA-induced excitotoxicity by quenching ROS in hippocampal neurons.