Role of allopurinol on oxidative stress in caustic burn: cure for stricture?

An experimental study was conducted to investigate the effects of allopurinol, which inhibits the enzyme xanthine oxidase, on oxidative stress and on the prevention of stricture development after esophageal caustic injuries in rat. A randomized controlled study was conducted and 60 Wistar albino rats were divided into 6 equal groups, three groups for the acute phase and 3 groups for the chronic phase. Caustic esophageal burn was created by application of 37.5% NaOH to the distal esophagus. Allopurinol was administered at 40 mg/kg daily. Efficacy of the treatment for the acute phase was assessed by measuring tissue malondialdehyde (MDA), nitric oxide (NO) and glutathione (GSH) at the 3rd day; and for the chronic phase by determining tissue hydroxyproline content and histopathologic damage score at the 28th day. We found an increase in XO, MDA and GSH levels and a decrease in NO levels in the acute phase. Allopurinol reinstated the increase in XO significantly, while MDA, GSH and NO levels were reinstated insignificantly. There was no significant difference in means of tissue hydroxyproline content. Histopathologic damage scores were significantly lower in the allopurinol treated group. This study, which is to our knowledge, the first in the literature investigating the influence of allopurinol on caustic esophageal burn, reveals that allopurinol effects MDA, GSH and NO levels insignificantly in the acute phase of caustic esophageal burn and decreases fibrosis significantly in the chronic phase.