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With the aid of animal models it is possible to simulate the human intestinal bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD) by chemical damage of the intestinal mucosa. In humans, UC is considered as a risk factor for colo-rectal cancer. In our experiments dextrane sulfate sodium (DSS) model was used to induce inflammation in the rat colon. DSS damages the intestinal barrier function so that food-derived and bacterial antigens can immigrate into the tissue and cause inflammation.

The aim of this study was to investigate the influence of various types of apple juice on a DSS induced colitis in male rats. To investigate the time-course of the inflammation drinking water containing 3 % DSS (m.w. 36000-50000) was offered the animals for ten days ad libitum. Subsequently drinking water was offered for seven days ad libitum. Animals were sacrificed and tissue samples were taken from day 1-17 of the treatment. To investigate the influence of different apple juices on the inflammation apple pulp, cloudy apple juice, clear apple juice or a polyphenol-free control juice were offered the animals ad libitum for seven days before and after the ten days treatment with 3 % DSS solution. Tissue samples were taken at the end of the second juice application.

The analyzed parameters were bodyweight gain, ratio of colon weight/colon length, myeloperoxidase (MPO) activity and transforming growth factor beta 1 (TGF-beta1) levels.

A ten days application of 3 % DSS solution led to a uniform, for the animals well to cope, inflammation. At the eighth day of DSS treatment the animals showed diarrhea and rectal bleeding. Both declined two or three days after the end of DSS treatment. Inflammation was evident from the eighth day of DSS treatment and was still visible seven days after the end of DSS treatment. The healing process started two or three days after the end of DSS treatment. Within the DSS treated groups apple pulp, cloudy apple juice and clear apple juice enhanced the increase in TGF-beta1. By comparison of the DSS treated groups with their corresponding control groups the following parameters showed that apple pulp and cloudy apple juice attenuated the DSS induced colitis while clear apple juice had no effect on the inflammation: bodyweight gain, ratio of colon weight/colon length and MPO activity.

Our findings indicate that apple pulp and cloudy apple juice can attenuate DSS-induced inflammation in the rat colon, and may thus play a role in the prevention of colo-rectal cancer.

98th AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA