Gallotannic Acid

Gallotannic acid (tannic acid; a polygalloyl-glucose tannin) exerts protein-precipitating astringent activity on mucosal membranes, reducing permeability, inhibiting bacterial and viral adherence to epithelial surfaces, and promoting wound healing through protein cross-linking. Antimicrobial activity against gram-positive and gram-negative organisms occurs through disruption of bacterial cell membranes and enzyme inhibition. Antiviral activity involves binding to viral capsid proteins and blocking receptor attachment. Gallotannins are hydrolyzed in the gut to gallic acid and glucose, with gallic acid exhibiting antioxidant, anti-inflammatory, and antineoplastic activity through direct radical scavenging and induction of apoptosis in tumor cells.