Protective effect of an ethanol extract mixture of Vitis amurensis, Aralia cordata, and Glycyrrhizae radix against ischemia-induced brain injury in rats and excitotoxicity in cultured neurons

Abstract

Vitis amurensis, Aralia cordata, and Glycyrrhizae radix have been widely used as oriental medicinal plants in Korea, China and Japan and found to possess anti-oxidative and anti-inflammatory activities. A previous study demonstrated a protection of an ethanol extract (SSB) of a mixture of three medicinal plants of Vitis amurensis, Aralia cordata, and Glycyrrhizae radix against β amyloid protein-induced memory impairment. The current study was conducted to investigate the neuroprotective effect of SSB against ischemiainduced brain injury. Transient focal cerebral ischemia was induced by 2 hr middle cerebral artery occlusion followed by 24 hr reperfusion (MCAO/reperfusion) in rats. Oral administration of SSB (5, 10 and 25 mg/kg) 30 min before and 1 h after MCAO, and 1 h after reperfusion reduced MCAO/reperfusion-induced brain infarct and edema formation. SSB also inhibited development of behavioral disabilities in MCAO/reperfusion-treated rats. Exposure of cultured cortical neurons to 500 μM glutamate for 12 hr resulted in neuronal cell death. SSB (1-10 μg/mL) inhibited glutamateinduced neuronal death, elevation of intracellular calcium concentration ([Ca2+]i), and generation of reactive oxygen species (ROS). These results suggest that the neuroprotective effect of SSB against ischemia-induced brain damage might be associated with its anti-excitotoxic activity and that SSB may have a therapeutic role for prevention of neurodegeneration in stroke.