Gelatin tannate reduces the proinflammatory effects of lipopolysaccharide in human intestinal epithelial cells

BACKGROUND: Gelatin tannate is a mixture of tannic acid and gelatin. Tannic acid has astringent properties, due to its capacity to form protein–macromolecular complexes, as well as antibacterial and antioxidant properties. However, little is known about its anti-inflammatory properties. PURPOSE: To evaluate the anti-inflammatory activity of gelatin tannate by quantifying the suppression of key molecules produced during inflammatory events in lipopolysaccharide (LPS)-stimulated human intestinal cells. METHODS: Intercellular adhesion molecule-1 (ICAM-1) expression was determined by Western blot analysis; interleukin-8 (IL-8) and tumor necrosis factor-α (TNF-α) concentrations were measured by enzyme-linked immunosorbent assays in Caco-2 cells 24 hours after treatment with LPS (1 μg/mL) in presence of different concentrations of gelatin tannate. RESULTS: ICAM-1 is induced on a wide variety of cells by inflammatory stimuli such as LPS. Our results have shown gelatin tannate as a potent inhibitor of ICAM-1 expression in LPS-stimulated Caco-2 cells. IL-8 and TNF-α are important inflammatory mediators, recruiting neutrophils and T-lymphocytes. Together with LPS, adding gelatin tannate at different concentrations induced a dose-dependent inhibition of IL-8 and TNF-α released by Caco-2 cells. CONCLUSION: These results suggest that gelatin tannate exerts anti-inflammatory effects by inhibiting the specific cytokines and adhesion molecules involved in several inflammatory disorders.