Effect and mechanism of Coeloglossum viride var. bracteatum extract on scopolamine-induced deficits of learning and memory behavior of rodents

The aim of the present study is to investigate the effect and mechanism of Coeloglossum viride var. bracteatum extract (CE) on scopolamine-induced learning and memory deficits.  Learning and memory deficits of mice were evaluated by step-down passive avoidance test.  Long-term potentiation of rats was detected in the dentate gyrus of hippocampus.  Brain acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) activities were also determined.  The results showed that scopolamine impaired learning and memory performance and  LTP induction in hippocampus.  Oral administration of CE (5, 10, and 20 mg·kg^-1) significantly alleviated  scopolamine-induced memory deficits measured by step-down test (P<0.05).  CE (5 mg·kg^-1, ip) significantly reversed the inhibitory effect of scopolamine on LTP in rats.  In addition, CE was found to increase the activity of ChAT in rat brain.  These results suggested that CE could alleviate scopolamine-induced learning and memory deficits, which might be due to the LTP-improvement and ChAT activity enhancement.