N-acetyl-cysteine improves anastomotic wound healing after radiotherapy in rats

Aim: This study was designed to determine the effects of intraperitoneally or orally administered N-acetylcysteine (NAC) on anastomotic healing of irradiated rats. Methods: Thirty-two male Wistar albino rats were randomized into four groups containing 8 rats each: I; standard resection plus anastomosis, II; radiation plus standard resection plus anastomosis, III; radiation plus standard resection plus anastomosis plus oral NAC, IV; radiation plus standard resection plus anastomosis plus intraperitoneal NAC. Four types of assessment were performed: bursting pressure, hydroxiproline (OHP) content, histopathology, and biochemical evaluation, including serum malondialdehyde (MDA), advanced oxidation protein products (AOPP), reduced glutathione (GSH) and superoxide dismutase (SOD) activities. Results: Group comparisons demonstrated that bursting pressure was significantly higher in NAC treated rats. The mean tissue OHP concentration in the anastomotic tissue was significantly lower in irradiated rats (group II) than in the other groups. NAC treatment caused increased activity of SOD and GSH. In contrast, MDA levels were found to be decreased in groups III and IV. Histopathological analysis revealed that NAC administration, either orally or intraperitoneally, leads to a better anastomotic healing in terms of reepithelialization, perianastomotic fibrosis, ischemic necrosis, and muscle layer destruction. Conclusion: The present study supports the hypothesis that NAC administration alleviates the negative effects of radiotherapy on anastomotic healing. Nevertheless, the underlying mechanisms responsible for this protective effect is unknown today. © 2011 Informa Healthcare USA, Inc.