Aim: 

To analyze the effects of Salmonella-mediated gene therapy using Cu-Zn superoxid dismutase (SOD1) and a mutant of monocyte chemoattractant protein-1 (7ND-MCP1) on chemically induced colitis.

Methods: 

Dextran sodium sulphate (DSS)-induced colitis in female Wistar rats was treated with SOD1 and 7ND-MCP1 encoded by plasmids carried by Salmonella typhimurium SL7207 applied daily during one week. Faecal consistency, clinical status and body weight were monitored during the whole experiment. Malondialdehyde (MDA) and advanced oxidation protein products were measured as markers of oxidative stress. Interleukin 1, inteleukin 6 and tumour necrosis factor alpha were quantified in colon and plasma samples using ELISA.

Results: 

Faecal consistency and MDA showed a slight improvement in SOD1 and 7ND-MCP1 + SOD1 groups, but not in the 7ND-MCP1 group. Surprisingly, no differences were found in body weight increase, markers of oxidative stress in plasma and even in inflammatory markers in colon homogenates. Plasma concentrations of IL1, IL6 and TNFalpha were lower in the treatment groups than in the DSS group. However, DSS induced inflammation could only be confirmed by plasma IL1 and TNFalpha but not IL6.

Discussion: 

Although some parameters showed a tendency to be improved by the bacteria-mediated antioxidative and anti-inflammatory gene therapy, the inflammation in the experimental DSS group was rather minor in comparison to other studies. Whether this is caused by the choice of gender and strain of the experimental animals will be studied.