Potential inhibitors of microglial activation from the roots of Wikstroemia lichiangensis W. W. Sm

Research on natural inhibitors of microglial overactivation derived from members of the Wikstroemia genus revealed that the extract of W. lichiangensis W. W. Sm. Has a remarkable inhibitory effect on nitric oxide production in overactivated microglia. In the present study, thirty-four compounds, including five undescribed sesquiterpenoids [wiksdauctins A–B (1–2) and wikscarotins A–C (3–5)] and one undescribed lignan [wikstroeminasin A (8)], were isolated from a 95% EtOH extract of W. lichiangensis roots using bio-guided phytochemical research. The structures of the isolated compounds were elucidated using comprehensive spectroscopic analyses. Furthermore, their anti-neuroinflammatory effects were evaluated in lipopolysaccharide-stimulated BV-2 microglia. Seventeen isolated compounds exhibited stronger inhibitory effects than positive control minocycline (IC50 values of 67.08 ± 1.95 μM), with IC50 values ranging from 7.35 ± 2.51 to 64.49 ± 3.38 μM. The findings of this study imply that the isolated compounds might serve as potential therapeutic agents for neurodegenerative diseases. Six undescribed and twenty-eight known compounds were characterized from the roots of W. lichiangensis, which had the inhibitory effects on NO production in LPS induced BV-2 microglia. [Display omitted] •Six undescribed compounds were identified from Wikstroemia lichiangensis.•All compounds were evaluated for NO inhibitory effects in LPS-induced BV-2 cells.•Inhibitory effects of seventeen compounds were reported.