Effect of 3-amino benzamide, a poly(adenosine diphosphate-ribose) polymerase inhibitor, in experimental caustic esophageal burn.

INTRODUCTION: The enzyme poly(adenosine diphosphate-ribose) polymerase affects the repair of DNA in damaged cells. However, its activation in damaged cells can lead to adenosine triphosphate depletion and death. This study was designed to investigate the efficacy of 3-amino benzamide (3-AB), a poly(adenosine diphosphate-ribose) polymerase inhibitor, on the prevention of esophageal damage and stricture-formation development after esophageal caustic injuries in rat.

MATERIALS AND METHODS: Forty-five rats were allocated into 3 groups: sham-operated, untreated, and treated groups. Caustic esophageal burn was created by instilling 15% NaOH to the distal esophagus. The rats were left untreated or treated with 3-AB 10 mg/kg per day intraperitoneally. All rats were killed on the 28th day. Efficacy of the treatment was assessed by measuring the stenosis index and histopathologic damage score and biochemically by determining tissue hydroxyproline content, superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and protein carbonyl content (PCC) in esophageal homogenates.

RESULTS: Treatment with 3-AB decreased the stenosis index and histopathologic damage score seen in caustic esophageal burn rats. Hydroxyproline level was significantly higher in the untreated group as compared with the group treated with 3-AB. Caustic esophageal burn increased MDA and PCC levels and also decreased SOD and GPx enzyme activities. On the contrary, 3-AB treatment decreased the elevated MDA and PCC levels and also increased the reduced SOD and GPx enzyme activities.

CONCLUSION: 3-Amino benzamide has a preventive effect in the development of fibrosis by decreasing tissue damage and increasing the antioxidant enzyme activity in an experimental model of corrosive esophagitis in rats.