Depolymerized Products of -Carrageenan as a Potent Angiogenesis Inhibitor

Since angiogenesis is involved in initiating and promoting several diseases such as cancer and cardiovascular events, this study was designed to evaluate the anti-angiogenesis of low-molecularweight (LMW), highly sulfated λ-carrageenan oligosaccharides (λ-CO) obtained by carrageenan depolymerization, by CAM (chick chorioallantoic membrane) model and human umbilical vein endothelial cells (HUVECs). Significant inhibition of vessel growth was observed at 200 μg/pellet. A histochemistry assay also revealed a decrease of capillary plexus and connective tissue in λ-CO treated samples. λ-CO inhibited the viability of cells at the high concentration of 1 mg/mL, whereas it affected the cell survival slightly (>95%) at a low concentration (<250 μg/mL), and HUVEC is the most sensitive to λ-CO among three kinds of cells. Furthermore, the inhibitory action of λ-CO was also observed in the endothelial cell invasion and migration at relatively low concentration (150-300 μg/mL), through down-regulation of intracellular matrix metalloproteinases (MMP-2) expression on endothelial cells. Taken together, these findings demonstrate that λ-CO is a potential angiogenesis inhibitor with combined effects of inhibiting invasion, migration, and proliferation.