7-Deoxy-trans-dihydronarciclasine Isolated from Lycoris chejuensis Inhibits Neuroinflammation in Experimental Models.

Overactivated microglia and persistent neuroinflammation hold an important role in the pathophysiology of neurodegenerative diseases. The extract of Lycoris chejuensis (CJ) and its active compound, 7-deoxy-trans-dihydronarciclasine (named E144), attenuated expressions of pro-inflammatory factors, including nitric oxide, prostaglandin E₂, inducible nitric oxide synthase, cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), and interleukin 6, secreted by lipopolysaccharide-activated BV-2 microglial cells, as measured by an enzyme-linked immunosorbent assay or western blotting. In contrast, CJ extract and E144 promoted the secretion of the anti-inflammatory cytokine, interleukin 10. Moreover, we found that E144 attenuated the expression of TNF-α and COX-2 in the cerebral cortex of lipopolysaccharide-treated mice and/or T2576 transgenic mice as well as reduced the reactive immune cells visualized by ionized calcium-binding adaptor molecule 1. Our results suggest the possibility of E144 to serve as a potential anti-neuroinflammatory agent by preventing excess production of pro-inflammatory factors.