Biol. Pharm. Bull. 28(10) 1915—1918 (2005)

noni is indigenous to the Hawaian and Tahitian islands. A number of constituents have already been isolated from this plant, and they include anthraquinones, flavonoids, iridoids and oligosaccharides. Moreover, it has been established that the constituents of Hawaiian noni differ from those of noni found on the Indian sub-continent. Cimanga reported on the isolation of iridoids with complement-inhibitory activity from Morinda spp. Moreover, the roots of Morinda officinalis (Rubiaceae) continue to be traditionally used to treat rheumatoid arthritis, diabetes and hypertension in North East Asia rather than M. citrifolia, which is also used in traditional medicine and said to have similar pharmacologic effect. Yang et al. have reported on the anthraquinones from a CHCl3 extract of M. officinalis. To isolate the active principle of M. officinalis, we used activity-directed fractionation. The main iridoid glycoside isolated, monotropein, was also examined by antinociceptive assay (hot plate test and writhing test) in mice and anti-inflammatory assay in rats with carrageenan-induced edema. Our investigation of the components of M. officinalis, resulted in the isolation of iridoid glycosides that were somewhat different from noni constituents. It is commonly known that many iridoid glycosides or other natural glycosides are easily hydrolyzed by intestinal bacteria. Therefore, we adopted oral administration approach for in vivo model to find the exact active compounds.