Diarylheptanoid from Pleuranthodium racemigerum with in vitro prostaglandin E(2) inhibitory and cytotoxic activity

Bioactivity-guided fractionation of an ethanolic extract of the rhizome of Pleuranthodium racemigerum, a tropical Zingiberaceae species from Northeastern Australia, resulted in the isolation and structural elucidation of 1-(4''-methoxyphenyl)-7-(4'-hydroxyphenyl)-(E)-hept-2-ene (1), a new diarylheptanoid related to curcumin. Compound 1 was a fairly potent inhibitor of prostaglandin E(2) production in 3T3 murine fibroblasts (IC(50) approximately 34 microM) and also displayed moderate cytotoxicity against this cell line (IC(50) = 52.8 microM). The compound also demonstrated cytotoxic activity against the P388D1 murine lymphoblast cell line (IC(50) = 117.0 microM) and four human cell lines: Caco-2 colonic adenocarcinoma (IC(50) = 44.8 microM), PC3 prostate adenocarcinoma (IC(50) = 23.6 microM), HepG2 hepatocyte carcinoma (IC(50) = 40.6 microM), and MCF7 mammary adenocarcinoma (IC(50) = 56.9 microM). The cytotoxicity of compound 1 closely resembled that of curcumin, in terms of both IC(50) values and dose-response curves.