Identification of anti-tumor components from toad venom.

Secretion of granular glands from the skin of amphibians is a fascinating resource of active substances, particularly for cancer therapy in clinical practice of Traditional Chinese Medicine. A variety of anti-tumor peptides have been isolated from different toads and frogs; however, no anti-tumor peptides are reported in toad venom of Bufo gargarizans. Firstly, soluble fraction from fresh toad venom (FTV) was compared with that from dried toad venom (DTV), using HPLC analysis. It was revealed that FTV has a different HPLC chromatography compared with DTV. Soluble fraction of FTV is more toxic to SH-SY5Y cells than that of DTV, as evaluated by MTT assay. Secondly, it was identified that protein components from soluble fractions of FTV and DTV possess different patterns by SDS-PAGE analysis, and proteins from FTV are also more toxic than that from DTV. Thirdly, an immobilized basic fibroblast growth factor (bFGF) affinity column was used to isolate bFGF-binding components from soluble fraction of FTV, and it was identified that bFGF-binding components prohibited bFGF-dependent neurite growth of SH-SY5Y cells. Finally, it was identified that bFGF-binding components activated apoptosis via upregulation of caspase-3 and caspase-8 expression in SH-SY5Y cells. These data suggest that FTV contains active components that interact with bFGF and activate apoptosis in SH-SY5Y cells.