title: Neuroprotection of aucubin in primary diabetic encephalopathy.
abstract: Hippocampal neuronal apoptosis accompanied by impairment of cognitive function occurs in primary diabetic encephalopathy. In this study, we investigated the neuroprotective mechanism of the iridoid glycoside, aucubin, using rats (n=8). Diabetes mellitus was induced in the rats by intraperitoneal (i.p.) injection of streptozotocin (60 mg/kg body weight). After 65 d, half of the DM rats were administered aucubin (5 mg/kg; i.p.) for 15 d, yielding treatment DM+A. A third group of rats received no streptozotocin or aucibin, and served as controls (CON). Encephalopathy was assessed using Y-maze behavioral testing. Rats were euthanized on Day 87, and hippocampi were excised for visual (light and transmission electron microscopic) and immunochemical (Western blot; immunohistochemical) assessments of the CA1 subfield for apoptosis and expression of regulatory proteins Bcl-2 and Bax. Treatment responses to all the parameters examined (body weight, plasma glucose, Y-maze error rates, pyramidal cell ultrastructure, proportions of apoptotic cells, levels of expression of Bcl-2 and Bax, and survivability of neuronal cells) were identical: there were highly significant differences between DM and CON groups (P<0.001), but the effects were significantly moderated (P<0.01) in DM+A compared with DM. These findings confirm the association of apoptosis with the encephalopathic effects of diabetes mellitus, and suggest a major role of the expression levels of Bcl-2 and Bax in the regulation of apoptotic cell death. All of the results suggest that aucubin could effectively inhibit apoptosis by modulating the expressions of Bcl-2 and Bax genes.
authors.affiliation: Department of Bioscience and Biotechnology, Dalian University of technology, Dalian 116024, China.
authors.forename: HongYu
authors.initials: H
authors.lastname: Xue
authors.forename: LiJi
authors.initials: L
authors.lastname: Jin
authors.forename: Lei
authors.initials: L
authors.lastname: Jin
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: DanQing
authors.initials: D
authors.lastname: Li
authors.forename: YanQiu
authors.initials: Y
authors.lastname: Xia
authors.forename: YaNan
authors.initials: Y
authors.lastname: Lu
authors.forename: YongPing
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001925:Brain Damage, Chronic / Q000209:etiology / Q000517:prevention & control*; D048909:Diabetes Complications / Q000517:prevention & control*; D003921:Diabetes Mellitus, Experimental / Q000150:complications; D005960:Glucosides / Q000627:therapeutic use*; D007150:Immunohistochemistry; D057888:Iridoid Glucosides; D039823:Iridoids / Q000627:therapeutic use*; D008297:Male; D046529:Microscopy, Electron, Transmission; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D005960:Glucosides; D057888:Iridoid Glucosides; D039823:Iridoids; D018696:Neuroprotective Agents; C006650:aucubin