Pinocembrin Protects Human Brain Microvascular Endothelial Cells against Fibrillar Amyloid-β1−40Injury by Suppressing the MAPK/NF-κB Inflammatory Pathways

Abstract

Cerebrovascular accumulation of amyloid-β(Aβ) peptides in Alzheimer’s disease (AD) may contribute to disease progression through Aβ-induced microvascular endothelial pathogenesis. Pinocembrin has been shown to have therapeutic effects in AD models. These effects correlate with preservation of microvascular function, but the effect on endothelial cells under Aβ-damaged conditions is unclear. The present study focuses on thein vitroprotective effect of pinocembrin on fibrillar Aβ1−40(fAβ1−40) injured human brain microvascular endothelial cells (hBMECs) and explores potential mechanisms. The results demonstrate that fAβ1−40-induced cytotoxicity in hBMECs can be rescued by pinocembrin treatment. Pinocembrin increases cell viability, reduces the release of LDH, and relieves nuclear condensation. The mechanisms of this reversal from Aβmay be associated with the inhibition of inflammatory response, involving inhibition of MAPK activation, downregulation of phosphor-IKK level, relief of IκBαdegradation, blockage of NF-κB p65 nuclear translocation, and reduction of the release of proinflammatory cytokines. Pinocembrin does not show obvious effects on regulating the redox imbalance after exposure to fAβ1−40. Together, the suppression of MAPK and the NF-κB signaling pathways play a significant role in the anti-inflammation of pinocembrin in hBMECs subjected to fAβ1−40. This may serve as a therapeutic agent for BMEC protection in Alzheimer’s-related deficits.