Tryptanthrin is an alkaloid tryptophan derivative originally isolated from various plants and found to have antimicrobial actions. Among its many actions in cells, it inhibits both 5-lipoxygenase and cyclooxygenase-2 (IC50s = 600 and 64 nM, respectively). Tryptanthrin suppresses angiogenesis in vivo and blocks signaling through VEGFR2 at the level of ERK1/2 signaling in vitro. It also prevents ERK signaling through Nrf2, reducing oxidative stress-induced hepatocytotoxicity.
