Neuroprotective Effects of Flax Lignan Against NMDA‐Induced Neurotoxicity In Vitro

Abstract

Flax Lignan (FLL), a chemical widespread within the plant and animal kingdoms, has antioxidant, antiinfectious, and antitumor activities. However, little is known about the effects of FLL on the central nervous system (CNS). The neuroprotective actions of FLL against N-methyl-d-aspartate (NMDA) are investigated in primary cultured cortical neurons by MTT assay. The expression levels of proteins related to apoptosis and GluN2-containing receptor were detected by Western blot analysis. Intracellular Ca(2+) was measured under a confocal laser scanning microscope. After challenged with 100μM NMDA for 30min, loss of cell viability and excessive apoptotic cell death were observed in cultured cortical neurons. FLL protected the neurons against the NMDA-induced cell loss in a concentration-dependent manner. FLL also significantly inhibited the neuronal apoptosis induced by NMDA exposure through reversing intracellular concentration of Ca(2+) overload and balancing of Bcl-2 and Bax expression. Furthermore, FLL significantly reversed the upregulation of GluN2B-containing NMDA receptors by exposure to NMDA, but did not affect the expression of GluN2A-containing NMDA receptor. These findings suggest that FLL protects cortical neurons by inhibiting the expression of GluN2B-containing NMDA receptor and regulating the Bcl-2 family.