Magnesium lithospermate B protects neurons from N-methyl-D-aspartic acid injury and attenuates kainic acid-induced neurodegeration in FVB mice.

Magnesium lithospermate B (MLB) is one of the major bioactive components of Radix Salviae miltiorrhizae (Dan Shen), which is a Chinese traditional herbal medicine with therapeutic effects on cardiovascular and cerebrovascular diseases. The aim of this study was to investigate the neuroprotective effects of MLB on N-methyl-D-aspartic acid (NMDA)-injured neurons and against kainic acid (KA)-induced neurodegeneration in mice. In cultured mouse primary hippocampal neurons, MLB significantly reduced NMDA-induced cell death and promoted neurite growth in a dose-dependent manner. In FVB mice, MLB attenuated KA-induced neurodegeneration. Additionally, MLB prevented the decrease in phosphorylated Akt and glycogen synthase kinase-3β (GSK-3β) levels both in NMDA-injured neurons and KA-injured mouse brain. This effect was blocked by phosphoinositide 3-kinase (PI3K) inhibitor LY294002 and Akt inhibitor triciribine, thus indicating the neuroprotective effects of MLB are most likely mediated by the PI3K/Akt/GSK-3β pathway. Taken together, these results show the efficacy and underlying mechanism of MLB against neuronal injury and raise its therapeutic potential in neurodegenerative diseases.