Anti-neuroinflammatory benzofurans and lignans from Praxelis clematidea

Praxelis clematidea (Asteraceae) is a harmful invasive alien weed, which cause huge destruction of ecological environment and economic losses. In this study, 22 compounds were isolated and purified from the whole plant of P. clematidea, including 4 benzofurans (1-4), 18 lignans (5-22), and five of which were new compounds (1, 3, 4, 9, 10). Various spectroscopic analysis methods were utilized to elucidate their chemical structures. The inhibitory effects of the isolated compounds on NO release from BV-2 microglia cells induced by LPS were investigated. Most of the compounds showed pronounced anti-neuroinflammatory activity. Additionally, the new compounds 3, 4 and 10 exhibited significant anti-neuroinflammatory effects, and the biological activities were further confirmed by immunoblotting, quantitative PCR and immunofluorescence staining assays. As results, this study provided a new idea for the further treatment and utilization of P. clematidea as anti-neuroinflammatory agents in health-benefit products.