Inhibitory effect of iridoids on Epstein-Barr virus activation by a short-term in vitro assay for anti-tumor promoters.

The in vitro anti-tumor promoting effect of the methanolic extracts of iridoids containing three plants and several pure iridoids isolated from other plants, has been evaluated. The alcoholic extracts of Paederia scandens, P. scandens var. mairei and the Ayurvedic herbal remedy Picrorhiza kurrooa were tested against the Epstein-Barr virus. Among the 15 iridoids evaluated, the glycoside, paederoside, displayed the highest order of anti-tumor promoting activity.