Xanthium strumarium suppresses degranulation and pro-inflammatory cytokines secretion on the mast cells

Objective : Previously, the methanol extracts of the semen of Xanthium strumarium could involved anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated Raw 264.7 cells. We evaluated the anti-allergic effects of X. strumarium on rat basophilic leukemia (RBL-2H3) cells. Methodes : To investigate the effect of X. strumarium on the phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-induced RBL-2H3 cells. The effects of X. strumarium on the degranulation and the pro-inflammatory cytokines secretion and expression from RBL-2H3 cells were evaluated with β-hexosaminidase assay, ELISA, and RT-PCR analysis. In addition, we examined the effects of X. strumarium on nuclear factor (NF)-κB activation and IκB-α degradation using Western blot analysis. Results : X. strumarium inhibited degranulation and secretions and expressions of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin (IL)-4 and cyclooxygenase (COX)-2, on stimulated RBL-2H3 cells, however, X. strumarium not affect cell viability. In stimulated RBL-2H3 cells, the protein expression level of nuclear factor-kappa B (NF-κB) was decreased in the nucleus by X. strumarium. In addition, X. strumarium suppressed the degradation of inhibitory protein IκB-α protein in RBL-2H3 cells. Conclusion : These results suggest that X. strumarium inhibits the degranulation and secretion of pro-inflammatory cytokines through blockade of NF-κB activation and IκB-α degradation.Key words : Xanthium strumarium, Cytokine, Cyclooxygenase (COX)-2, Nuclear factor-kappa B (NF-κB), IkappaB-alpha (IκB-α)