5-aminosalicylic acid (5-ASA) can reduce levels of oxidative DNA damage in cells of colonic mucosa with and without fecal stream.
BACKGROUND
No studies have evaluated the effectiveness of 5-ASA against oxidative DNA damage in experimental models of diversion colitis.


OBJECTIVE
To evaluate the effects of 5-ASA against oxidative DNA damage in an experimental model of diversion colitis.


METHODS
Twenty-six Wistar rats were divided into two groups corresponding to sacrifice at 2 or 4 weeks after fecal diversion of the left colon by means of proximal colostomy and distal mucosa fistula. Each group was divided into two subgroups according to intervention in excluded colon performed with 0.9% saline solution or 5-ASA. Level of oxidative DNA damage was determined by comet assay in cells obtained from segments with and without fecal stream before and after H2O2 challenge. For statistical analysis, was used one-way analysis of variance (ANOVA), adopting a 5% significance level (P<0.05).


RESULTS
Levels of DNA damage were always higher in colon segments without fecal stream, regardless of the intervention solution employed. DNA damage in colon segments with and without fecal stream in animals irrigated with 5-ASA was lower when compared with those treated with saline solution, regardless of time of irrigation. These levels remained lower after intervention with 5-ASA, even after H2O2 challenge.


CONCLUSIONS
Enema with 5-ASA reduces oxidative DNA damage in epithelial cells of colon segments without fecal stream, even after H2O2 challenge, confirming the effects of 5-ASA against DNA damage by oxygen free radicals.
Post-Graduate Program in Health Sciences, São Francisco University Medical School, Bragança Paulista, SP, Brazil. carolinecaltabiano@hotmail.com
Caroline
C
Caltabiano
Felipe Rodrigues
FR
Máximo
Ana Paula Pimentel
AP
Spadari
Daniel Duarte
DD
da Conceição Miranda
Marcia Milena Pivatto
MM
Serra
Marcelo Lima
ML
Ribeiro
Carlos Augusto Real
CA
Martinez
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D003092:Colitis / Q000188:drug therapy / Q000473:pathology; D003106:Colon / Q000187:drug effects* / Q000473:pathology; D004249:DNA Damage / Q000187:drug effects*; D005243:Feces; D006861:Hydrogen Peroxide / Q000009:adverse effects; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000473:pathology; D008297:Male; D019804:Mesalamine / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
D000894:Anti-Inflammatory Agents, Non-Steroidal; D019804:Mesalamine; D006861:Hydrogen Peroxide