Beneficial effect of synbiotics on experimental colon cancer in rats

Abstract

Background/aims: The aim of this study was to investigate the influence of a synbiotic preparation (a mixture of six probiotics and a prebiotic) on aberrant crypt foci (ACF) formation, dysplasia, inflammation, and colitis-like lesions in experimental colon cancer in rats.

Materials and methods: Sixty male rats were categorized into three groups of 20 animals each. Group A was administered 1,2-dimethylydrazine, 15 mg/kg body weight (BW), once a week for 2 weeks. Group B was administered 1,2-dimethylydrazine at the same dose plus synbiotic, started after the second dose of carcinogen and lasted for 5 weeks. Group C was administered synbiotic plus carcinogen from the beginning of the experiment and lasted for 7 weeks. Animals were killed at the end of week 7.

Results: At the end of the experiment, the animals that received carcinogen plus the synbiotic had 100%, whereas the animals that received only carcinogen has 70% survival. Animals of groups B and C had significantly lower percentage of inflammation, colitis-like lesions, and ACF dysplasia than animals of group A, whereas those of group C had the least pathological lesions.

Conclusion: Synbiotics seem to protect against the appearance of preneoplastic colon lesions in rats. The results of this experimental study suggest that treatment with a synbiotic preparation exerts significant antimutagenic properties against the development of preneoplastic lesions in rats.

Figure 1

All animals that have received were alive compared with 14 of 20 animals that have received only carcinogen (p=0.001)

Figure 2

Group C versus Group A: Normal-appearing crypts were found in 38% of the animals in Group C and 7% in Group A (p=0.044); inflammation was found in 28% of the animals in Group C and 86% in Group A (p<0.0001)

Figure 3

Group C versus Group A Colitis-like lesion was found in 29% (p<0.019) and ACF with dysplasia in 23% in Group A (p<0.058) None of these lesions were found in Group C

Figure 4

Group B versus Group A Normal mucosa was found in 23% of the animals in Group B and 7% in Group A (p<0.044) Inflammation was detected in 40% of the animals in Group B and in 86% in Group A (p<0.0001)

Figure 5

Group B versus Group A Colitis-like lesions were detected in 5% of the animals in Group B and 29% in Group A (p<0.019). ACF with dysplasia was seen in 3% of the animals in Group B and 23% in Group A (p=0.058)

Figure 6

Group C versus Group B Normal mucosa was found in 35% of the animals in Group C and in 25% in Group B (p=0.0044) Inflammation was detected in 30% of the animals in Group C and in 40% in Group B (p<0.0001)

Figure 7

Group C versus Group B: Colitis-like lesions were detected in 5% and ACF dysplasia in 5% of the animals in Group B There was no such observation in Group C

Figure 8

Abnormally large crypts with dilated or slit-like opening (long arrow), architectural distortion, and abnormal cytologic features such as hyperchromasia and increased nuclear to cytoplasmic ratio (short arrows); HE stain; 100×

Figure 9

Slit-like opening of large abnormal crypts that shows cell stratification, nuclear enlargement, and increased nuclear-to-cytoplasmic ratio (thick arrows) in comparison with normal crypts (thin arrows)

Figure 10

Abnormal crypts with architectural distortion consists of cells that shows nuclear enlargement, hyperchromasia, and increased nuclear-to-cytoplasmic ratio (long arrow) in comparison with normal crypts (short arrows)

Figure 11

Colitis-like lesion: active changes consist of inflammatory infiltration by neutrophils, plasma cells, and crypt abscesses (neutrophils in gland lumen/arrow)