Soy Isoflavone Antagonizes the Oxidative Cerebrovascular Injury Induced by β-Amyloid Peptides 1–42 in Rats

Numerous evidences have shown that the antioxidative properties of soy isoflavone (SIF) have beneficial effects on prophylaxis of neurodegeneration, however, the mechanism is still not fully illustrated. As cerebrovascular dysfunction could initiate a cascade of events leading to pathogenesis of Alzheimer’s disease, we tried to investigate whether SIF could protect the cerebrovascular system due to antagonizing oxidative damage induced by Aβ1–42 in present study. In addition, NF-E2-related factor 2 (Nrf2) signaling pathways in the cerebrovascular tissue of Wistar rats were investigated to identify the potential cerebrovascular protective targets of SIF. Research results showed that SIF reduced the excessive production of nitrotyrosine in cerebrovascular tissue induced by Aβ1–42, and maintained redox homeostasis by increasing the level of GSH and GSH/GSSG. Moreover, SIF could alleviate the down-regulation of Nrf2, γ-glutamylcysteine synthetase, Heme oxygenase-1 expressions in cerebrovascular tissue induced by Aβ1–42 and suppress the increase of Kelch like ECH protein-1 (Keap1). These data suggested that SIF might reduce the cerebrovascular oxidative damage induced by Aβ1–42 through regulating the Nrf2 signaling pathway. The mechanisms of SIF modulating the potential target Nrf2 might be associated with Keap1 expression.