Xanthotoxol is a coumarin and a major component in C. monnieri that has diverse biological activities. It inhibits proliferation of HeLa and HepG2 cells in vitro (IC50s = 23.59 and 15.57 μM, respectively). Xanthotoxol increases histamine release from mast cells and decreases secretion of TNF-α, IL-4, and IL-1β from RBL-2H3 cells induced by DNP-human serum albumin (DNP-HSA). It is nematocidal against M. incognita (IC50 = 68 mg/L). In vivo, xanthotoxol inhibits predatory mouse and rat killing behavior in dogs and cats when administered at doses ranging from 3 to 100 mg/kg and 5 to 20 mg/kg, respectively. It reduces amphetamine-induced hypermobility in mice and hamsters. Xanthotoxol (5 and 10 mg/kg) reduces brain edema, neutrophil infiltration, blood-brain barrier disruption, production of IL-1β, TNF-α, IL-8, and nitric oxide (NO), and levels of intercellular adhesion molecule-1 (ICAM-1) and E-selectin in a rat model of focal cerebral ischemia.
