Isolation and partial characterization of heparin-binding protein from Korean mistletoe (Viscum album coloratum)

Korean mistletoe (Viscum album coloratum), a different subspecies of Viscum album from European mistletoe has shown that it has various biological activities including anti-cancer and immune modulating activities. The main leading compounds were known to be lectins. Additionally, we isolated heparin-binding protein (HBP) fractions from Korean mistletoe extract (KM) and characterized them. Heparin is a highly sulfated polysaccharide that is used clinically as anticoagulant. More than 100 HBPs with various biological activities are identified. These proteins fall into diverse groups, including circulatory system, several growth factors, extracellular matrix and lipid metabolism. HBP fractions of Korean mistletoe were isolated by heparin-conjugated sepharose affinity chromatography and were characterized in terms of molecular weight, partial sequencing, and biological activities. The isolated HBP fractions showed strong cytotoxicity against human and murine tumor cell lines. Furthermore, the inhibitory effectors on tumor angiogenesis and tumor growth were observed. In immunomodulating activity, HBP fractions induced the production of several cytokines such as TNF-α, IL-1β and IL-6 in mouse peritoneal cells and NO production in RAW 264.7 cells. Results demonstrated that the isolated HBP fractions may have the potential to be used as anti-tumor and immunomodulating agents.