Cinobufotalin is a cardiotonic steroid or bufotalin. It is mainly obtained from the skin secretion of the giant toad.

Cinobufotalin has been used:

• as a standard to bound them with the Fab fragment of an anti-digoxin antibody (Digibind) to rapidly detect its presence in blood by the fluorescence polarization immunoassay for digitoxin
• to treat human cancer cell lines/MCF-7 cells to examine the steroid receptor coactivator-3 (SRC-3) protein concentrations and evaluate its efficacy as SRC small-molecule inhibitors (SMIs)
• as a standard to calibrate the high-performance liquid chromatography (HPLC) and calculate the total quantity of bufadienolides present in the nuchal gland fluid of Rhabdophis tigrinus

Cinobufotalin, a diuretic, and a hemostatic agent can stimulate cytotoxic effect in cultured lung cancer cells. It can suppress the development of A549 cells in vivo. Cinobufotalin possesses antitumor activity and enhanced chemotherapeutic effect. It can inhibit the vascular endothelial growth factor and epidermal growth factor receptor expression to prevent the development and metastasis of the tumor. It may be beneficial to advance gastric cancer (GC) patients. This safe auxiliary antitumor agent can reduce the adverse events related to chemotherapy.