Effect of five triterpenoid compounds from the buds of Aralia elata on stimulus-induced superoxide generation, tyrosyl phosphorylation and translocation of cytosolic compounds to the cell membrane in human neutrophils.

The buds of Aralia elata (Miq.) Seem (Japanese angelica tree) have long been used as a tonic, antiarthritic and antidiabetic agent in China and Japan. We have isolated five triterpenoids, congmuyanosides A, C, D, echinocystic acid and 3-O-[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-hederagenin from the buds of Aralia elata , and investigated their effects on stimulus-induced superoxide generation in human neutrophils. Congmuyanoside A, echinocystic acid and 3-O-[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-hederagenin suppressed the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) in a concentration-dependent manner. Congmuyanosides C, D and echinocystic acid significantly suppressed the superoxide generation induced by phorbol 12-myristate 13-acetate (PMA) and arachidonic acid (AA). The compounds also suppressed fMLP- and AA-induced tyrosyl or PMA-induced serine/threonine phosphorylation and translocation of cytosolic compounds, p47 (phox), p67 (phox) and Rac to the cell membrane.