In vivo immunomodulatory activity of fucoidan from brown alga Undaria pinnatifida in sarcoma 180-bearing mice

Bioactivities of fucoidan, a class of marine algal polysaccharides, vary depending on the original algal species. The aim of this study was to explore the in vivo immunomodulatory activity of fucoidan from Undaria pinnatifida, a brown alga with a long history of medicinal and food uses in East Asia, in sarcoma 180 (S180) subcutaneous xenograft-bearing mice. Results showed that oral administration of fucoidan significantly enhanced the phago-cytotic function of mononuclear phagocytic system, increased the serum levels of Th1 cytokines interleukin-2, interferon-gamma and tumor necrosis factor-alpha, promoted spleen T lymphocyte responses, increased the infiltration of CD11c + dendritic cells (DCs) into transplanted sarcoma tissues, and upregulated the surface expression of MHC class II and costimulatory molecule CD86 on bone marrow-derived CD11c+ DCs in S180-bearing mice. Overall, fucoidan from Undaria pinnatifida represents an antitumor adjuvant stimulating both innate and adap-tive immune responses for patients with advanced soft tissue sarcomas.