Anticancer Effect of Fucoidan on Breast Cancer Figure 6. Fucoidan induced apoptosis in vivo. Representative photographs of the tumor sections examined by TUNEL assay. TUNEL-positive cell nuclei (dark brown) were observed under a fluorescence microscope (6400). The number of apoptotic cells was counted 5 random fields (6400) in a blinded manner. Each bar represents the ‘‘apoptosis index’’, expressed as mean 6 SD. Fucoidan treatment caused a significantly higher percentage of TUNEL-positive apoptotic cells. **P,0.01 vs Control. doi:10.1371/journal.pone.0043483.g006 Figure 7. Fcoidan inhibited the tumor angiogenesis in vivo. Representative photographs of the tumor sections examined by immunohistochemical staining for CD34 showing tumor vasculature (6400). The microvessel number was reduced apparently in the tumors belonging to the mice treated with fucoidan. Each bar represents the average vessel number for each group, expressed as mean 6 SD. *P,0.05 vs Control. doi:10.1371/journal.pone.0043483.g007 PLOS ONE | www.plosone.org 5 August 2012 | Volume 7 | Issue 8 | e43483