Affiliation: Institute of Chemistry, University of the Philippines, Diliman, Quezon City 1101 Philippines.
Iridoids discussed in this review were chosen based on their anti-inflammatory activity and their having various different bioactivities. Harpagoside is the major iridoid glycoside (0.5-1.6%) in Harpagophytum procumbens, an herbal medicine for rheumatologic conditions. The stem bark of C. ovata is used as an anti-inflammatory drug and catalposide is the main constituent. Geniposide is a main iridoid glucoside of Gardenia jasmoides, 56.2 mg / 500 mg extract. Gardenia fruits are used for the treatment of anti-inflammatory, hepatic and gall bladder diseases. Catalpol, known for its neuroprotective activity, is the major constituent of the roots of Rehmannia glutinosa, which are traditionally used for the treatment of auditory diseases such as tinnitus. Aucubin, which is frequently found as a natural constituent of many traditional medicinal plants, is used in the alleviation of chronic allergic inflammatory disease. PicroLiv, an anti-inflammagen, is a standardized fraction from the root and rhizome of Picrorhiza kurroa containing picrosides I and II and kutkoside. Both aucubin and PicroLiv have potent hepatoprotective activity.