Effect of three triterpenoid compounds isolated from root bark of Aralia elata on stimulus-induced superoxide generation and tyrosyl phosphorylation and translocation of p47(phox) and p67(phox) to cell membrane in human neutrophil.

摘要

BACKGROUND: Root bark of Aralia elata is used as a folk medicine for neurasthenia, rheumatism, diabetes, hepatitis virus and spasm of the stomach in China, Japan and Russia. METHODS: The effect of three triterpenoid compounds isolated from root bark of A. elata on stimulus-induced superoxide generation and tyrosyl phosphorylation and translocation of p47(phox) and p67(phox) to cell membrane was investigated. The three compounds examined were Elatoside A, Elatoside C, and Tarasaponin V. RESULTS: When the cells were preincubated with these compounds, the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was suppressed in a low concentration range. However, the superoxide generation was significantly enhanced by 40 micromol/l triterpenoid, and was again suppressed in the higher concentration range. In the case of superoxide generation induced by phorbol 12-myristate 13-acetate (PMA), the compounds had no obvious effect on the superoxide generation in low concentration but suppressed that at 40 micromol/l. These compounds also efficiently suppressed the superoxide generation induced by arachidonic acid (AA) at 10 micromol/l. In parallel to the effect on the fMLP-induced superoxide generation, these compounds suppressed fMLP-induced tyrosyl phosphorylation and the translocation to membrane of cytosolic compounds, p47(phox) and p67(phox) at 10 and 80 micromol/l but not at 40 micromol/l. CONCLUSIONS: Triterpenoid saponins examined in this study effect stimulus-induced superoxide generation and tyrosyl phosphorylation and translocation to membrane of p47(phox) and p67(phox) in a concentration-dependent manner, and may have some pharmaceutical applications.