Lignans and neolignans from the twigs and leaves of <i>Wikstroemia indica</i> (L.) C.A. Mey. with their effects on LPS-induced IL-1β and IL-10 secretion in RAW 264.7 macrophages

Eight compounds were isolated from the water-soluble fraction of <i>Wikstroemia indica</i> (L.) C.A. Mey., including two new neolignans (isonitidanin-4<i>-O</i>-<i>β</i>-D-glucoside (<b>3</b>) and <i>threo</i>-citrusin B (<b>6</b>)), four known neolignans (<b>1</b>, <b>2</b>, <b>4</b>, and <b>5</b>), along with two previously reported lignans (<b>7</b> and <b>8</b>). Spectral analysis (1D, 2D NMR, and HR-ESI-MS/MS) was used to identify their chemical structures. Except for compound <b>3</b>, which was not evaluated due to limited sample availability, the influence of the remaining compounds on IL-1β and IL-10 secretion in LPS-stimulated RAW 264.7 macrophages was assessed using ELISA. Among these, compound <b>8</b> significantly reduced IL-1β secretion, with an IC₅₀ value of 9.73 ± 1.26 µM. These results not only expand the known chemical diversity of lignans from <i>W. indica</i> but also suggest that certain lignans possess promising anti-inflammatory activity and may serve as valuable lead compounds for the development of new immunomodulatory agents.