Suppression of cytokine production and cell adhesion molecule expression in human monocytic cell line THP-1 by Tripterygium wilfordii polysaccharide moiety

Extracts of the vine-like plant Tripterygium wilfordii (TW) have been widel y used in China as an immunosuppressant and anti-inflammatory drug for the treatments of rheumatoid arthritis, lupus erythematosus and other inflammat ory disorders. In this study the molecular mechanisms of action of three TW extracts (ethanol, aqueous, polysaccharide) on the expression of inflammat ory cytokines and adhesion molecules were investigated by RT-PCR and immuno fluorescence binding techniques. The lipopolysaccharide (LPS)-mediated stim ulatory effects of tumor necrosis factor-alpha (TNF-alpha) cytokine product ion and cell adhesion molecule (CD11c, CD18, CD14, CD54) expression in huma n monocytic THP-1 cells were modulated by treatments of the TW extracts or tacrolimus (FK506). The TW polysaccharide moiety exhibited more profound im munosuppressive properties than the aqueous and ethanol extracts. Biochemic al characterization of the polysaccharide moiety revealed a major molecular weight of 22 kDa (viz. PSP22). The PSP22 was found to be a potential immun osuppressant that manifests the necessary immunomodulating properties. (C) 2000 Elsevier Science Inc. All rights reserved.