Suppression of adhesion and invasion of hepatoma cells in culture by tea compounds through antioxidative activity

To determine the actions of tea components on the invasion of a rat ascites hepatoma cell line of AH109A and to understand their modes of action, the cancer cells were co-cultured with a rat mesentery-derived mesothelial cell monolayer in the presence of tea components. The synergistic effects of(-)-epicatechin (EC) with (-)-epigallocatechin gallate (EGCG) on AH109A invasion were demonstrated. Further study showed that 10 muM of EGCG or theaflavins, or 2.5 muM of ethylenediaminetetraacetic (EDTA) entirely abolished the increase in AH109A adhesion and invasion stimulated by reactive oxygen species (ROS) from the hypoxanthine-xanthine oxidase system. Our results suggest that (OH-)-O-.- and other ROS-scavenging activity of EGCG and theaflavins may be responsible for the inhibition of . OH-- and related ROS-potentiated AH109A adhesion and invasion to the cultured rat mesothelial cell monolayer. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved.