Astilbin inhibits the adhesion of T lymphocytes via decreasing TNF-alpha and its associated MMP-9 activity and CD44 expression.

Our previous study has revealed that astilbin, a flavonoid isolated from the rhizome of Smilax glabra, improves an immunological liver injury and its mechanism includes an inhibition of the lymphocyte adhesion. The present study further examined the anti-adhesive activity in various assays by using human leukemia T cell line Jurkat cells. We found that astilbin inhibited the adhesion of Con A or PMA-activated Jurkat cells to fibronectin, type IV collagen, hyaluronic acid, and [corrected] ECV-304 cells. Astilbin inhibited the adhesion of Jurkat cells to PMA-activated but not non-activated ECV-304 cells without any influence on the survival of the ECV-304 cells and Jurkat cells. Astilbin also inhibited the CD44 expression and TNF-alpha production in Jurkat cells. In the co-culture assay between Jurkat cells and ECV-304 cells, the MMP-9 secretion from Jurkat cells was inhibited after astilbin-treatment, while the exogenous TNF-alpha increased the MMP-9 secretion in a dose-dependent manner. These findings suggest that the inhibition of T lymphocyte adhesion by astilbin may be related to the reduction of the CD44 expression and TNF-alpha production in the cells, which may further cause a decreased MMP-9 secretion.