Is Green Tea All It Is Brewed Up to Be? Our Results Suggest It May Not Be

Abstract

Abstract Inflammation underlies multiple disorders, including cardiovascular disease, diabetes mellitus, and cancer. Naturally occurring compounds are being investigated for potential medicinal benefit in the treatment of multiple disorders. The published literature indicates that epigallocatechin gallate (EGCG), derived from green tea leaves, has antioxidant, anti-inflammatory, anti-cancer, and antimicrobial properties. Through a series of cell-culture-based assays, EGCG was determined to be strongly proinflammatory at 10 µM and cytotoxic at 50 µM, concentrations utilized in multiple published reports, in both vascular endothelial cells and monocyte-derived macrophages. Furthermore, EGCG suppressed wound healing in vascular endothelial cells at both 10 and 50 µM. A 1-µM EGCG treatment appeared to have no effect on vascular endothelial cells or monocyte-derived macrophages when carried out for less than 3 days. Concentrations of 1, 10, and 50 µM EGCG were assessed for the ability to promote the biocompatibility of polymers using a THP-1 cell adhesion assay and a Chandler Loop ex vivo model of blood perfusion using whole equine blood. No significant changes in the number of adhered cells were seen in either assay, suggesting that EGCG does not promote the biocompatibility of commonly used polymers in medical devices. Taken together, our results indicate that EGCG is proinflammatory at the concentrations assessed and not suitable as a therapy to promote biocompatibility.