A galactolipid possesses novel cancer chemopreventive effects by suppressing inflammatory mediators and mouse B16 melanoma

Chia Chung Hou, Yi Ping Chen, Jyh Horng Wu, Chi Chang Huang, Sheng Yang Wang, Ning Sun Yang, Lie Fen Shyur

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49 Citations (Scopus)

Abstract

Crassocephalum rabens (Asteraceae) is a popular anti-inflammatory folk medicine and food supplement. We investigated the cancer chemopreventive bioactivity of C. rabens phytocompounds in vitro and in vivo using cell- and gene-based bioassays and a mouse B16 melanoma model. The bioactive glyceroglycolipid 1,2-di-O-α-linolenoyl-3-O-β-galactopyranosyl-sn- glycerol (dLGG) that was identified from C. rabens was found in vitro and in vivo to be a potent nitric oxide (NO) scavenger. dLGG treatment inhibited both mRNA and protein expression of inducible NO synthase and cyclooxygenase-2 (COX-2) in murine macrophages and inhibited COX-2 gene transcription in 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated B16 cells. In immunohistochemical studies, dLGG inhibited TPA-induced expression of COX-2 and nitration of proteins in mouse skin. dLGG could also significantly inhibit lipopolysaccharide-induced prostaglandin E2 production in murine macrophages. Furthermore, dLGG prevented nuclear translocation of cytoplasmic nuclear factor-κB (NF-κB) by suppressing IκBα phosphorylation and degradation. Structure-activity relationship study by electrophoretic mobility shift assay indicated that the dilinolenoylglycerol moiety in dLGG is the essential structural feature preventing NF-κB·DNA complex formation. A dLGG-enriched extract from C. rabens (10 mg/kg) markedly suppressed B16 melanoma growth in C57BL/6J mice following i.p. administration, an effect comparable with that of cisplatin, a cancer chemotherapeutic drug. This study shows the detailed molecular mechanism(s) underlying the anti-inflammatory and tumor-suppressive effects of a natural galactolipid.

Original languageEnglish
Pages (from-to)6907-6915
Number of pages9
JournalCancer Research
Volume67
Issue number14
DOIs
Publication statusPublished - Jul 15 2007
Externally publishedYes

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ASJC Scopus subject areas

  • Cancer Research
  • Oncology

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