Neuroprotective effect of palmul-chongmyeong-tang on ischemia-induced learning and memory deficits in the rat.

Ginseng Radix, Atractylodis Macrocephalae Rhizoma, Poria, Glycyrrhizae Radix, Angelicae Gigantis Radix, Ligusticum Rhizoma, Rehmanniae Radix, Paeoniae Radix, Acori Graminei Rhizoma, and Polygalae Radix have been widely used as herbal medicine against ischemia. In order to test the neuroprotective effect of a novel prescription, the present study examined the effects of Palmul-Chongmyeong-Tang (PMCMT) consisting of these ten herbs on learning and memory in the Morris water maze task and the central cholinergic system of rats with cerebral ischemia-induced neuronal and cognitive impairments. After middle cerebral artery occlusion (MCAO) for 2 h, rats were administered with saline or PMCMT (200 mg/kg, p.o.) daily for 2 weeks, followed by their training to the tasks. In the water maze test, the animals were trained to find a platform in a fixed position during 6 d and then received a 60 s probe trial on the 7th day following removal of the platform from the pool. Rats with ischemic insults showed impaired learning and memory of the tasks and treatment with PMCMT produced a significant improvement in escape latency to find the platform in the Morris water maze. Consistent with behavioral data, treatment with PMCMT also reduced the loss of cholinergic immunoreactivity in the hippocampus induced by cerebral ischemia. These results demonstrated that PMCMT has a protective effect against ischemia-induced neuronal and cognitive impairments. The present study suggested that PMCMT might be useful in the treatment of vascular dementia.