Catalpol Protects Cerebral Infarction And Improves Memory

Background and Purpose:As one of the big three human deadly disease in the world, stroke has disability, neurological deficits, cognitive impairments, and so on. But clinic is lack of drug not only to improve cognitive impairments but also to promote the neurobehavior function recovery. Catalpol is an iridoid from Rehmannia glutinosa, which is a widely used as traditional Chinese medicine for Neuroprotective or neurodegenerative diseases. So catalpol is a potential new drug to treat stroke and improve memeory.This study was performed to determine advantage of catalpol compared with a free radical scavenger and a neuroprotectives as edaravone, and memory improvement drug as oxiracetam at first, and then to investegate the mechanisms especialy there are differences between edaravone and catalpol.Methods:Part One:The comparative study of catalpol, edaravone and oxiracetam on the cerebral ischemic(1) The pMCAO model and drug administrationExcept the sham group, all mouse were underwent the left side of permanent middle cerebral artery occlusion. Animals were divided into 5 groups:sham, model, oxiracetam, edaravone, catalpol as treatment group. Drugs were injected into the tail vein for three days.(2) Zea Longa’s ScoreThe neurological function of all mouse was evaluated daily with a 5-point scale after 1.2 and 3 day stroke.(3) Cerebral blood flow ratiosThree days later, we measured blood flow ratios in the difference between normal (right) and ischemic (left) brain by LDF.(4) TTC stainingFive mouse were taken respectively from each of the group to make TTC staining after 3 days.(5) HE and Nissl stainingThe ischemic (left) brain of hippocampus was displayed by HE and Nissl staining. Part Two:The comparative study of catalpol, edaravone and oxiracetam on memory impairment(1)The memory obstruction model model and drug administrationAnimals were divided into 7 groups:normal, model, oxiracetam, edaravone, three doses of catalpol as treatment group. In all groups, except for the saline control, learning and memory dysfunction in mice was induced by SCOP (2 mg·kg-1) intraperitoneal injection 30 mins before behavioral testing after drugs were injected into the tail vein for three days..(2) Morris water maze testMorris water maze tesconsists of positioning navigation experiment and space exploration experiment.Part Three:Effect of catalpol on memory impairment of mechanisms(1) Following the Morris water maze test, blood and serum were collected via the fossa orbitalis vein. The hippocampus of the brains were removed after decapitation.(2 ELISA analysisThe activity of ChAT and AChE were measured by chromometry,the level ACh and BDNF were measured by ELISA.(3) Western blot analysisWestern blot analysis of the effect of Catapol on the expression of M 1、M 2、ChAT and AChE in hippocampus. Results:(1) Effect of catalpol on NeuroethologyCatapol and edaravone significantly reduced Zea Longa’s scored<0.05) compared with the model group. The results suggested that catapol can improve neurobehavioral outcome.(2) Effect of catalpol on cerebral blood flow ratiosCompared with the model group,catapol and edaravone significantly increased cerebral blood flow (P< 0.05).It showed that catapol can improve rCBF.(3) Effect of catalpol on cerebral infract areaThere was significant decreasment in catapol and edaravone groups (P< 0.01),compared with the model group. It showed that catapol can decrease the cerebral infract area.(4) Effect of catalpol on cytomorphology in hippocampusMouse in sham group did not show any histopathological abnormalities and those in ischemia group showed marked cell damages with pycnotic nucleus and eosinophilia in hippocampus. Oxiracetam also reduced neuronal loss and moderate morphologic changes. Edaravone and catalpol significantly decreased neuronal cell damage induced by pMCAO. Catapol and edaravone obviously improved the nerve cells in hippocampus compared with the model group.(5) Effect of catalpol on Morris water maze testCompared with the model group,catapol and oxiracetam significantly decreased escape latency time(P< 0.05) and increased the numbers of crossing platform area(P < 0.05). The results suggested that catapol can improve memory.(6) Effect of catalpol on ChAT and AChEThe AChE activity was no significant difference in the blood serum among all the groups. The hippocampal AChE activity was not significantly different between among the model and catalpol groups. ChAT activity in the hippocampus significantly increased in the oxiracetam group and catalpol (P< 0.05). The results suggested that catapol can increase ChAT activity. (7) Effect of catalpol on ACh and BDNFCompared with the model group, catapol and oxiracetam significantly increase the level of ACh and BDNF, the mechanism may be related with cholinergic system and higher BDNF expression.(8) Effect of catalpol on M 1、M2、ChAT and AChE in hippocampusCompared with the model group, catapol advanced the expression ofM 1、M2、ChAT protein,lowered the expression of AChE protein.Conclusion:Compared with memory improvement drug as oxiracetam, edaravone treated cerebral ischemic. Compared with a neuroprotectives as edaravone, catalpol and oxiracetam promoted memory. Catalpol has neurprotection effects and memory-enhancing.