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.

Aucubin prevents interleukin-1 beta induced inflammation and cartilage matrix degradation via inhibition of NF-κB signaling pathway in rat articular chondrocytes

“…Aucubin, a natural compound has been found in various plants including leaves of Aucuba japonica [15] and Eucommia ulmoides [16], proves to possess a variety of pharmacological effects [17][18][19]; [20], notably, anti-inflammatory effect [21]. It has been reported to have blocked the translocation of NF-κB by inhibition of IκB degradation and phosphorylation, a critical step in early inflammatory responses [22].…”

Encefalopatia Diabética E Depressão: Dano Oxidativo No Cérebro

“…Com estrutura molecular semelhante ao catalpol e de forma similar com eficaz ação antiapoptótica, a acubina possui função neuroprotetora associada ao favorecimento da atividade de enzimas antioxidantes endógenas e a capacidade de eliminar o excesso de ER e proteger contra o dano a lipídeos de membrana, melhorando a glicemia em modelo experimental de encefalopatia diabética 84 . Dados de estudos experimentais anteriores demonstram que a acubina pode evitar a apoptose modulando a expressão de genes relacionados a apoptose Bcl-2 e Bax 85 . O efeito neuroprotetor, a melhora da cognição e proteção contra a perda de neurônios ocorre tanto em curto quanto em longo prazo no tratamento experimental com acubina 86 .…”

Aucubin alleviates oxidative stress and inflammation via Nrf2-mediated signaling activity in experimental traumatic brain injury

“…Recently, its anti-inflammatory and antioxidative functions have become a focus of research. Studies have shown that Au provides neuroprotective effects via anti-inflammation and anti-oxidative properties [26][27][28][29][30]. Nevertheless, its molecular mechanisms are not well understood.…”