Introduction: This study aimed to investigate whether epigallocatechin-3-gallate (EGCG) shows antioxidant activity against angiotensin II (Ang II)-induced human umbilical vein endothelial cell (HUVEC) apoptosis. Materials and Methods: The viability of HUVECs was revealed by MTT and LDH assay. The cell apoptosis was detected by FITC-PI assay. A fluorescent probe assay was used to measure the reactive oxygen species (ROS) generation in HUVECs. Mitochondrial permeability transition pore (MPTP) opening, mitochondrial membrane potential, and caspase-3, -4, -8, -9 activities were also measured. Results: We found that Ang II treatment increased the generation of ROS, enhanced MPTP opening and cytochrome c release, activated caspase-3/9, and consequently induced HUVEC apoptosis. EGCG treatment-suppressed Ang II induces the oxidative stress of HUVECs and mitochondria-related cell apoptosis. We also showed that the antioxidant activity pathway, including cytochrome c release, MPTP opening, and caspase-3/9 activation, is a key endogenous defensive system in HUVECs, provoking Ang II exposure. Our study revealed that increased expression of Nrf2 by EGCG could partially repress Ang II-induced injury effects. Conclusions: All of our findings indicated that EGCG treatment provides a protective effect for Ang II-induced HUVEC apoptosis by decreasing oxidative stress and ameliorating mitochondrial injury. (C) 2017 S. Karger AG, Basel