Fucoxanthin Exerts Anti-Tumor Activity on Canine Mammary Tumor Cells via Tumor Cell Apoptosis Induction and Angiogenesis Inhibition

Simple Summary Fucoxanthin is a carotenoid that reportedly exhibits anticancer activity against different types of cancer cells. However, the activity of fucoxanthin in canine mammary gland tumors has not been extensively investigated. In this study, we evaluated fucoxanthin against canine mammary tumor cells (CMT-U27) and human umbilical vein endothelial cells (HUVECs). Our results indicated that fucoxanthin induced apoptosis via caspase activation and suppressed angiogenesis in CMT-U27 cells. Moreover, fucoxanthin inhibited tube formation and cell migration in HUVECs and CMT-U27 cells, indicating that it possessed anti-angiogenic potential. In conclusion, fucoxanthin induced tumor cell death and inhibited angiogenesis. Therefore, we propose that fucoxanthin can be considered a prospective therapeutic agent for canine mammary gland tumors. Fucoxanthin is a carotenoid derived from brown algae. It is known to exhibit anticancer activity, including the promotion of apoptosis and cell cycle arrest in several tumors. However, it remains unclear whether fucoxanthin exhibits anticancer activity against mammary gland tumors. In this study, we evaluated fucoxanthin activity against canine mammary tumor cells (CMT-U27) and human umbilical vein endothelial cells (HUVECs) to investigate its effect on cell viability, migration, tube formation, and angiopoietin 2 (Ang2) expression. Our results showed that fucoxanthin induced apoptosis via caspase activation in CMT-U27 cells. In rat aortic ring assay, fucoxanthin suppressed endothelial cell sprouting. Furthermore, fucoxanthin inhibited tube formation and migration in HUVECs. The number of migrated cells was assessed using CMT-U27 cells. The results demonstrated that fucoxanthin exerted anti-angiogenic activity on HUVECs and CMT-U27 cells by promoting Ang2 expression. In conclusion, our results demonstrated that fucoxanthin induced tumor cell death and inhibited angiogenesis, suggesting that fucoxanthin could be considered as a promising therapeutic agent for canine mammary gland tumors.