Probiotics administration ameliorate azoxymethane induced-carcinogenesis by reducing the formation of aberrant crypt foci and modulation oxidative stress in rats

BACKGROUND/AIM: Aberrant crypt foci (ACF) are early lesions in the neoplastic induction found in the rat colon of the carcinogenic model. ACF is one of the first changes in the colon that lead to colorectal cancer (CRC). Probiotics and fermented foods are well known for their beneficial role in gut health and previous studies showed their therapeutic effects on gastrointestinal diseases. The aim of this study is to investigate the preventive role of Propionibacterium freudenreichii and Faecalibacterium prausnitzii probiotics against CRC Induction in rats treated with azoxymethane (AOM).

METHODS: Rats were injected subcutaneously with 7mg/kg of AOM once a week for 3 weeks, and probiotics (P. freundreichii and F. prausnitzii) were administered orally at 1×10⁹ CFU/ml once a day for 6 weeks. 5- Fluorouracil (5-FU) as a reference anti-cancer drug was administered intraperitoneally at 35mg/kg 3 times a week for 6 weeks. After the treatment period, the colon of the rats was harvested and examined microscopically and histologically. Lipid peroxidation levels in colon tissues were measured using malondialdehyde (MDA) assay.

RESULT: Microscopical examination of harvested rat colons after methylene blue staining showed that the total number and multiplicity of ACF were significantly lower in the probiotics groups (p < 0.05) than the AOM control group that did not receive any intervention. Histological examination of the colon showed increased severe hyperplasia and dysplasia of the ACF in the AOM group compared to the treatment groups. Probiotics administration also reduced the levels of MDA in the colon of the rats compared to the rats in the AOM control group

CONCLUSION: These results suggest that probiotics play a preventive role in CRC initiation and development by slowing down ACF formation, reducing the severity of ACF lesions, and reducing lipid peroxidation levels in the colon.