Anti-inflammatory activity of unusual lupane saponins from Bupleurum fruticescens.

Extracts from Bupleurum fruticescens were examined for oral and topical anti-inflammatory activities. The BuOH extract proved to be active against carrageenan and tetradecanoylphorbol acetate acute edemas and allowed the isolation of three saponins identified by spectroscopic techniques as 3 beta-O-(O-alpha-L-rhamnopyranosyl-(1-->4)-O-[beta-D-glucopyranosyl- (1-->6)]-O-beta-D-glucopyranosyl)lup-20(29)-ene-23,28-dioic acid (fruticesaponin A), 3 beta-O-(O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl) lup-20(29)-ene-23,28-dioic acid 28-O-beta-D-glucopyranosyl ester (fruticesaponin B), and 3 beta-O-(O-alpha-L-rhamnopyranosyl-(1-->4)-O-[beta-D-glucopyranosyl- (1-->6)]-O-beta-D-glucopyranosyl)-lup-20(29)-ene-23,28-dioic acid 28-O-beta-D-glucopyranosyl ester (fruticesaponin C). These compounds were studied against carrageenan, tetradecanoylphorbol acetate, arachidonic acid and ethyl phenylpropiolate acute edemas. Fruticesaponin B, a bidesmosidic saponin with an unbranched saccharide moiety was the most active in all the tests applied.