Pectic polysaccharide isolated from Angelica gigas Nakai inhibits melanoma cell metastasis and growth by directly preventing cell adhesion and activating host immune functions.

The pectic polysaccharide (angelan) of Angelica gigas Nakai is an immunostimulator that activates the immune functions of B cells and macrophages. Here we investigated the effect of angelan on tumor growth and metastasis. Angelan was found to significantly prolong the survival rate of B16F10-implanted mice and to reduce the frequency of pulmonary metastasis of B16F10 melanoma. Moreover, the combined treatment of angelan and doxorubicin (a cytotoxic anticancer agent) more effectively inhibited tumor growth and metastasis than either compound alone. In the present study, we found that angelan directly inhibited cancer cell adhesion and invasion through the extracellular matrix, in addition to activating the immune functions of B cells and macrophages. These results suggest that angelan can inhibit tumor growth and metastasis by stimulating host immunity and directly inhibiting cancer cell adhesion.