In vitro covalent binding proteins of zerumbone, a chemopreventive food factor.

Zerumbone (ZER), a sesquiterpene in Zingiber zerumbet Smith, has been implicated as a promising chemopreventive agent. Here we found that ZER suppressed expression of pro-inflammatory genes (COX-2 and iNOS) and induced detoxification genes (GSTP1 and NQO1) in RAW264.7 macrophages. Using the ZER-bound Sepharose gel, it appeared ZER was covalently bound to proteins, Keap1 and HuR, that play key roles in these molecular mechanisms.