Epigallocatechin-3-gallate: Linking the neurogenesis, hippocampus, and Down syndrome

Epigallocatechin-3-gallate (EGCG) is thought to largely mediate the beneficial effects of green tea on the brain. In addition to its antioxidant and metal chelator actions, EGCG is an inhibitor of DYRK1A, one of the triplicated genes in Down syndrome (DS), a genetic condition caused by triplication of chromosome 21. Based on the key role of DYRK1A in the neurodevelopmental alterations that characterize DS, a few preclinical and two clinical studies have sought to establish whether EGCG may be a suitable therapy for DS. Some studies in the Ts65Dn model of DS show that EGCG improves hippocampal development and hippocampus-dependent cognitive performance, although other studies failed to find any behavioral improvement. The clinical trials show that EGCG ameliorates, albeit transiently, some aspects of cognition. These results give hope that EGCG may be of benefit for DS, although critical issues such as optimization of dose, route, and timing of administration need to be further investigated in thorough preclinical studies.