Immunomodulating properties of the diterpene andalusol

Andalusol [ent-13(16),14-labdadiene-6 alpha,8 alpha,18-triol], a labdane di terpene isolated from an anti-inflammatory extract of the medicinal plant S ideritis foetens Clem. was evaluated for immunomodulating properties. It ex hibited a dose-dependent inhibitory effect on the hemolytic activity of the classical complement pathway and also inhibited lymphocyte proliferation i nduced by concanavalin A at non-cytotoxic concentrations (1-100 mu M). No e ffect on the alternative pathway was observed. These results indicate that andalusol has immunosuppressive effects in vitro in addition to its anti-in flammatory activity.