Protection Of DMBC On Focal Crerebral Ischemic Injury In Rats And Its Mechanism

Aim:2-(3’,5’-Dimethoxybenzylidene) cyclopentanone (DMBC) is a novel syntheticsmall molecule compound by our group. To investigate the protective effects andmechanism of DMBC on focal crerebral ischemic injury in rats.Methods: In this study, we established two cerebral ischemia-hypoxia models in vivoand in vitro. Permanent middle cerebral artery occlusion (pMCAO) model was induced byusing intraluminal filament technique in rats. Hippocampal neuronal cell line HT-22cellwas exposed to a paradigm of ischemic insult by using an oxygen-glucose deprivation(OGD) device. DMBC was injected intraperitoneally (i.p.)1h or6h after the onset ofischemia. Neurological deficits were analyzed by scoring neurological deficits, grip forceand right foreclimb use and brain infarction volume was assessed with2,3,5-triphenyltetrazolium chloride (TTC). The injury of HT-22cells induced by OGD was detected withLDH assay. The active protein levels of cathepsin B were assessed with Western Blotanalysis. Immunofluorescence was employed to determine the translocation of cathepsin Bfrom lysosome to the cytoplasm.Results: DMBC reduced the infarction volume, improved the neurological deficitsand increases the expression of MAP2at24h after ischemia. LDH assay showed thatDMBC treatment could significantly reduce OGD-induced LDH release. Western Blotanalysis showed that DMBC treatment inhibited the OGD-induced increase in activecathepsin B. Immunofluorescence results showed that DMBC treatment inhibited thetranslocation of cathepsin B from lysosome to the cytoplasm.Conclusion: The current findings provide the first evidences that DMBC hasneuroprotection against cerebral ischemia, and its effect may be associated with theinhibition of cathepsin B activation.