Tannic acid, at nontoxic concentrations, specifically inhibits CXCL12-induced human monocyte migration (IC50, 7.5 μg/ml) but does not inhibit CCL2-, CCL3-, CCL5-, formylmethionylleucylphenylalanine (fMLP)-, or C5a-induced migration. The compound markedly blocks CXCL12 binding to THP-1 cells (IC50, 0.36 μg/ml). Tannic acid also inhibits CXCL12-induced, but not epidermal growth factor-induced, migration of MDA 231 breast tumor cells. Additionally, 0.5 μg/ml of tannic acid selectively inhibits CXCL12-mediated, but not basic fibroblast growth factor- or endothelial cell growth supplement-mediated, bovine aorta endothelial cell capillary tube formation.
In vivo
Given in drinking water, tannic acid enhances the survival rate of mice bearing syngeneic tumors.