Damnacanthal-induced anti-inflammation is associated with inhibition of NF-κB activity.

Morinda citrifolia L. (Rubiaceae), commonly called noni, is a traditional folk medicinal plant with a long history of use for several diseases. Its anti-inflammation activity has been proposed, but detailed knowledge of this antiinflammation mechanism remains unclear. Here, we investigated the effects of noni extract and its major bioactive component damnacanthal on anti-inflammation in vivo as well as in vitro. Our data demonstrate that noni extract and its bioactive component damnacanthal exhibit suppression of inflammation as evidenced by the suppression of paw and ear edema in rats and mice, and down-regulation of lipopolysaccharide-induced nuclear factor-κB (NF-κB) activity, respectively. As a result, the expression of pro-cytokines, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) were suppressed in the presence of damnacanthal. These results provide a potential use of damnacanthal in the treatment of inflammatory-related diseases.