The novel PARP inhibitor 5-aminoisoquinolinone reduces the liver injury caused by ischemia and reperfusion in the rat

Background: This study was designed to investigate the effects of 5-aminoisoquinolinone (5-AIQ), a water-soluble potent inhibitor of poly-(ADP-ribose) polymerase (PARP) in a rat model of liver ischemia-reperfusion injury.

Material/methods: Male Wistar rats were anesthetised with sodium pentobarbital (60 mg/kg, i.p.) and subjected to liver ischemia (for 30 minutes) and reperfusion (for 2 hours). Liver injury was assessed by measuring (i). the serum levels of transaminases, Lactate Dehydrogenase, gamma-glutamyl transferase, (ii). lipid peroxidation in liver tissue and (iii). by immunohistochemistry for PARP and intracellular adhesion molecule 1 (ICAM-1).

Results: Pre-treatment of rats (five minutes prior to onset of liver ischemia) with the PARP Inhibitor 5-AIQ (3 mg/kg, i.v.) rather than vehicle reduced the rise in the serum levels of transaminases, Lactate Dehydrogenase, and gamma-glutamyl transferase as well as the degree of lipid peroxidation (measured as levels of malondialdehyde in the liver) caused by ischemia-reperfusion of the liver. Liver sections obtained from 5-AIQ treated rats showed reduced PARP activation and less staining for ICAM-1.

Conclusions: Taken together, these results show that 5-AIQ, a new water-soluble potent inhibitor of poly-(ADP-ribose) polymerase, reduces the tissue injury associated with ischemia-reperfusion of the liver. We propose that 5-AIQ may be useful in the therapy conditions associated with ischemia-reperfusion of the liver which remains an important clinical problem during shock, liver surgery, and liver transplantation.