Terpenoids in plants are important sources for
drug discovery. In this study, we extracted
damsin and
coronopilin, two
sesquiterpene lactones, from Ambrosia arborescens and examined their anticancer effects on cell cultures.
Damsin and
coronopilin inhibited cell proliferation,
DNA biosynthesis and formation of cytoplasmic
DNA histone complexes in Caco-2 cells, with
damsin being more potent than
coronopilin. Further studies using the
luciferase reporter system showed that
damsin and
coronopilin also inhibited expressions of nuclear factor-κB (NF-κB) and signal transducer and activator of transcription-3 (STAT3), indicating that these
sesquiterpenes can interfere with NF-κB and STAT3 pathways. Finally, we examined the effects of two synthetic dibrominated derivatives of
damsin, 11α,13-dibromodamsin and 11β,13-dibromodamsin. While bromination appeared to weaken the antiproliferative effects of
damsin, the β epimer had strong inhibitory effects on STAT3 activation. In conclusion, the
sesquiterpene lactones damsin and
coronopilin have inhibitory effects on cell proliferation,
DNA biosynthesis and NF-κB and STAT3 pathways, thus being potentially important for discovery of drugs against
cancer.