Strigolactones: a plant phytohormone as novel anti-inflammatory agents.

Strigolactones (SLs) are a novel class of plant hormones with enormous potential for the prevention and treatment of inflammation. To further investigate the anti-inflammatory activities of SLs, a representative SL, GR24, and the reductive products of its D-ring were synthesized and their anti-inflammatory activities were fully evaluated on both and models. Among these compounds, the two most active optical isomers ( and ) demonstrated strong inhibitory activity on the release of inflammatory cytokines, including nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) by blocking the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways; they also greatly inhibited the migration of neutrophils and macrophages in fluorescent protein labeled zebrafish larvae.