Protective Effect And Mechanism Of Nicotiflorin On Multi-infarct Dementia

Objective : The present study aimed to determine whether nicotiflorin has a protective effect on multi-infarct cerebral ischemia -induced dementia(MID) in rats . Methods : we prepared MID model rats by injecting man-made dry micro-thrombi into the right hemisphere of rats through cervical internal carotid artery. The animals of administration groups were pretreated once daily with 30,60 and 120mg/kg nicotiflorin (i.g) from 5 days before the operation to either 14 days for Morris water maze study, 21 days for 8-arms radial maze tasks or 2 days after the ischemia operation for biochemical examination, neurological deficits score and HE staining to evaluate the neural impairments of rats. Morris water maze tests and eight-arms radial maze tasks were employed to evaluate spatial memory of rats.. Spectrophotometric assay was used to determine the content of acetylcholine (ACh), lactic acid(LD) , malondialdehyde (MDA), nitric oxide(NO) activity of acetylcholinesterase (AChE), lactate dehydrogenase(LDH), ATPase, superoxide dismutase (SOD) and NOS in the ischemia hemisphere and / or serum. Immunohistochemical assay was used to determine iNOS, eNOS and CHAT in brain hippocampus and cortex. Radioimmunity assay was employed to exam the content of ET-1 and CGRP in brain.Results The results showed that pretreatments with Nicotiflorin significantly improved performance of rats in 4 days of Morris water maze tests and 8-arms radial maze tasks. Significantly attenuated neurological deficits and pathological impairment, decreased the contents of LD, MDA,N0 and ET-1 in brain, decreased the contents of LD and MDA contents in serum, and increased contents of NO in serum; increased activity of AChE ,LDH, SOD and CHAT in the ipsilateral hemisphere and/or serum at day 3 after the ischemia operation.Conclusion: These results suggest that nicotiflorin improve the spatial memory of MID model rats. Demonstrated that Nicotiflorin could be effective in treatment of MID. Elevate content of NO and decreased content of ET-1 in serum could improve blood providing, this could be the possible mechanism for this Neuroprotection.