Testing the Anticancer Effect of Matcha Using Zebrafish as an Animal Model

Abstract

Cancer is the second leading cause of death worldwide. Triple-negative breast cancer (TNBC) patients show the poorest prognosis and survival and the highest metastasis prevalence among all breast cancer subtypes. Matcha (powder of Japanese green tea) has recently been associated with multiple health benefits, and in vitro studies showed the potential effect of matcha in inhibiting cancer development and metastasis. We aimed to determine the safe, non-toxic dose of matcha in zebrafish, and to investigate the anticancer effect of matcha on the metastasis and growth of human TBNC cells using a zebrafish xenograft model. Wild-type AB zebrafish were used to conduct multiple general toxicity assessments, including developmental, neuromuscular, and cardiovascular toxicities. 50 μg/ml and 100 μg/ml were determined as safe, non-toxic concentration of matcha in zebrafish. Afterward, the zebrafish xenograft model was successfully established by injection of MDA-MB-468 and MDA-MB-231 human TNBC cells. The tumor size and metastasis of the injected cancer cells were traced through CM-Dil red fluorescent dye. Exposure to non-toxic doses of matcha, showed a trend toward reduction in tumor size of MDA-MB-231 and MDA-MB-468 in a dose-dependent manner. Our results point to a potential dose-dependent anticancer effect of matcha on TNBC tumors; however, more extended observation periods after xenotransplantation are required to confirm the long-term anticancer effect of matcha on tumor growth and metastasis.