AIM:To evaluate the protective effects of preconditioning by α-lipoic acid (LA) in patients undergoing hepatic resection under inflow occlusion of the liver.METHODS:Twenty-four patients undergoing liver resection for various reasons either received 600 mg LA or NaCl 15 min before transection performed under inflow occlusion of the liver. Blood samples and liver wedge biopsy samples were obtained after opening of the abdomen immediately after inflow occlusion of the liver, and 30 min after the end of inflow occlusion of the liver.RESULTS:Serum levels of aspartate transferase and alanine transferase were reduced at all time points in patients who received LA in comparison to those who received NaCL. This was accompanied by reduced histomorphological features of oncosis. We observed TUNELpositive hepatocytes in the livers of the untreated patients, especially after 30 min of ischemia. LA attenuated this increase of TUNEL-positive hepatocytes. Under preconditioning with LA, ATP content was significantly enhanced after 30 min of ischemia and after 30 min of reperfusion.CONCLUSION:This is the first report on the potential for LA reducing ischemia/reperfusion injury (IRI) of the liver in humans who were undergoing liver surgery.Beside its simple and rapid application, side effects did not occur. LA might therefore represent a new strategy against hepatic IRI in humans.