Green tea catechins: protectors or threats to DNA? A review of their antigenotoxic and genotoxic effects
María del Carmen García‐Rodríguez, Sam Kacew
Abstract
This review examines the dual behavior of green tea catechins (GTCs), demonstrating the compound's ability to protect against oxidative stress and DNA damage while also potentially inducing genotoxicity under certain conditions. This duality may be attributed to their capacity both to scavenge free radicals and to generate these species via autooxidation. GTCs' antigenotoxic activities are mediated by multiple mechanisms, including reactive oxygen species (ROS) scavenging, regulation of endogenous antioxidant system (EAS), DNA repair, selective apoptosis of genetically compromised cells, epigenetic modulation, and metal ion (Cu, Fe, Zn) chelation-all of which collectively maintain cellular homeostasis and help reduce inflammation. However, at specific concentrations and in certain cellular conditions, GTCs' prooxidant effects-i.e., high ROS levels-might damage DNA and promote pro-apoptotic processes, potentially benefiting elimination of malignant cells. In contrast, lower ROS levels might stimulate antioxidant defenses via Nrf2 activation. Although evidence from both in vitro and in vivo studies indicates that GTCs consumption offers significant protection against diseases linked to oxidative DNA injury, the prooxidant properties of GTCs warrant careful consideration. Future research might focus on (1) optimizing GTC formulations for improved bioavailability, (2) assessing long-term outcomes, (3) evaluating toxicity at higher doses, and (4) investigating gut microbiome interactions. The dual antigenotoxic and genotoxic actions of GTCs indicate the potential role in preventive and complementary medicine, aligning with sustainable beneficial health strategies utilizing natural compounds.