Inhibitory Effects of Ginsenosides from the Root of Panax ginseng on Stimulus-Induced Superoxide Generation, Tyrosyl or Serine/Threonine Phosphorylation, and Translocation of Cytosolic Compounds to Plasma Membrane in Human Neutrophils

The effects of five ginsenosides (G-Rh 2 , -Rd, -Rb 1 , -Rb 2 , -Rh 1 ) isolated from the root of Panax gingseng on stimulus-induced superoxide generation in human neutrophils were evaluated by measuring the reduction of ferricytochrome c. The tyrosyl or serine/threonine phosphorylation of neutrophil proteins and translocation of p47 PhoX , p67 PhoX , and Rac to the plasma membrane were detected using specific monoclonal antibodies. G-Rh 2 significantly suppressed superoxide generation induced by N-formylmethionyl-leucylphenylalanine (fMLP), phorbol 12-myristate 13-acetate (PMA), and arachidonic acid (AA) in a concentration-dependent manner. G-Rh 1 showed a comparably lower suppression on fMLP-induced superoxide generation. G-Rd, -Rb 1 , and -Rb 2 also suppressed AA-induced superoxide generation in high concentrations. G-Rd and G-Rb 1 showed no effect on fMLP- and PMA-induced superoxide generation. FMLP-, PMA-, and AA-induced tyrosyl or serine/threonine phosphorylation and translocation of p47 PhoX , p67 PhoX , and Rac to the plasma membrane were in parallel with the suppression of the stimulus-induced superoxide generation.