Cepharanthine, a bisbenzylisoquinoline alkaloid, inhibits lipopolysaccharide-induced microglial activation.

Activation of microglial cells in the brain has been considered to be associated with various neurodegenerative diseases (NDD). In this study, cepharanthine, a bisbenzylisoquinoline alkaloid, was found to inhibit lipopolysaccharide (LPS)-induced microglial activation. Cepharanthine suppressed the release of nitric oxide (NO) by LPS-activated primary mouse cortical microglia and/or BV2 microglial cell line. Cepharanthine reduced LPS-induced mRNA expression of inducible NO synthase (iNOS), but it did not display direct NO-scavenging activity up to 100 μM in sodium nitroprusside (SNP) solution. Further studies revealed that cepharanthine suppressed the release of cytokines (TNF-α, IL-1β, and IL-6) by LPS-activated microglial cells. Cepharanthine may have potential in the treatment of neurodegenerative diseases accompanied by microglial activation.