Fulvene-5 is a chemical compound that exhibits antitumor activity. It functions as a potent inhibitor of NADPH oxidase 4 (NOX4) and possesses antioxidant properties. Additionally, Fulvene-5 acts as a reactive oxygen species (ROS) modifying agent and a powerful radioprotector.

Fulvene-5, administered at concentrations of 0.5-1.0 μM, significantly reduces the levels of Ang2, delta-like ligand 4 (DLL4), placental growth factor (PLGF), and Nrarp in bEnd.3 cells in a dose-dependent fashion. At a higher concentration (10?μM for 1 hour), Fulvene-5 shifts the adaptive responses of HCT116 TP53 wild type (WT) and HCT116 isogenic TP53 null mutant (Mut) cell cultures from promoting survival towards enhancing sensitivity to radiation, and inversely. These alterations coincide with the moving of survivin into the nuclei in TP53 WT cells and out to the cytoplasm in TP53 Mut cells. Additionally, the involvement of NOX4 in survivin-related adaptive responses is explored by diminishing NOX4 expression through the transfection of HCT116 cells with NOX4 siRNA oligomers, achieving approximately a 50% reduction in NOX4 expression.

Fulvene-5??treatment potently inhibits hemangioma growth in mice.