4-Hydroxyquinazoline is been used to inhibit PARP (poly(ADP-ribose) synthetase) which catalyzes covalent attachment of the ADP-ribose moiety of NAD+ to various proteins. This compound specifically and potently inhibits PARP-1. 4-HQN demonstrates the ability to decrease activation of transcription factor NFκB and AP-1 in lipopolysaccharide-induced shock. Mechanistic studies indicate that 4-HQN activates PI3-kinase/Akt pathway in the liver, spleen, and lung and down-regulates two elements of the MAP kinase system. Additionally, this agent has been observed to decrease ischemia-reperfusion-induced increase of protein oxidation, single-strand DNA breaks, lipid peroxidation, and mitochondrial reactive oxygen species production in the reperfusion period.
