Hellebrin is a cardiotonic glycoside which presents a bufadienolide-steroid structure. Besides ouabain, from the class of cardenolides hellebrin is the second unique water soluble cardiotonic glycoside. Extremely potent inhibitor of Na+/K+-ATPase (sodium pump) blocking the active efflux of Na+ and reuptake of K+ of this membrane enzyme. Shows a positive inotropic effect by increasing the intracellular Ca2+ concentration. Hellebrin is a strong immunosuppressor inhibiting T cell activity with much higher potency than cortisol or cyclosporin A Induces caspase-dependent apoptosis.
