Protective effects of extract of Coeloglossum viride var. bracteatum on ischemia-induced neuronal death and cognitive impairment in rats.

Our earlier study demonstrated that Coeloglossum viride (L.) Hartm. var. bracteatum (Willd.) extract (CE) significantly improved the impaired memory in mice caused by permanent two-vessel occlusion. To investigate whether chronic treatment with CE could influence cerebral ischemia-induced neuronal and cognitive impairments, we examined the effects of CE on two different kinds of cerebral injury: transient middle cerebral artery occlusion model of focal cerebral ischemia; four-vessel occlusion model of transient global forebrain ischemia. CE treatment (5 mg/kg, orally) significantly reduced lesion volume, and improved the performance of passive avoidance and rotarod motor tasks in transient middle cerebral artery occlusion rats. In the four-vessel occlusion model, neuronal cell loss in CA1 of hippocampus was significantly decreased and the performance in the Morris water maze was significantly improved in rats administered CE. We conclude that treatment with CE attenuated learning and memory deficits, motor functional disability, and neuronal cell loss induced by global or focal cerebral ischemia. These results suggest that CE may be a potential candidate for the treatment of vascular dementia.