Abstract:

Objective: To examined the antitumor effect of epigallocatechin-3-gallate (EGCG), and to investigate the
protective effect and potential mechanism of EGCG against myocardial injury triggered by the anticancer drug adriamycin
(ADR). Methods: A S180 tumor-bearing mice model was established and the mice were randomly divided into four
groups: control, ADR, EGCG and EGCG + ADR groups. Tumor and myocardial tissues were taken for the measurement
of lactate dehydrogenase (LDH), creatine kinase (CK) and Mn-superoxide dismutase (Mn-SOD) activities using detection
kits according to the manufacturer’s instructions. Meanwhile, apoptosis, reactive oxygen species (ROS) and mitochondrial
membrane potential level were measured by flow cytometry. Results: Compared with the control group, both EGCG and
ADR could significantly increase apoptosis of tumor cells. The combination of EGCG and ADR was superior to either
treatment alone. Moreover, the combined regimen could significantly reduce LDH and CK activities in myocardial tissue.
Compared with ADR alone, its combination with EGCG could significantly increase Mn-SOD activity in myocardial tissue,
reduce the production of ROS and ameliorate the loss of mitochondrial membrane potential. Conclusion: EGCG itself had
anti-tumor effect, and could synergize with ADR. In addition, EGCG had protective effect against myocardial damage
caused by ADR through improving the mitochondrial antioxidant defense capacity, ameliorating oxidative stress and
maintaining △Ψm homeostasis.

Key words: tumor, adriamycin (ADR), reactive oxygen species (ROS), epigallocatechin-3-gallate (EGCG)