The therapeutic effect of potentially probiotic Lactobacillus paracasei on dimethylhydrazine induced colorectal cancer in rats

This study aimed to evaluate the anti-carcinogenic and potential therapeutic effects of probiotic L. paracasei during colon carcinogenesis at the in-vivo model. 60 eight-week-old male Wistar rats were divided into five groups. The effects of L. paracasei B-14 (5 x 1010 CFU/kg/day for 7 consecutive weeks) on colorectal cancer (CRC) induced rats were studied in male Wistar rats treated with 1,2-dimethylhydrazine (30 mg/kg) for 12 weeks. The tumor incidence, number, size, and histopathological investigations, apoptosis occurrence, and cell proliferation were assessed in all groups (treated and control groups) after the end of treatment. Treatment of cancerous rats with L. paracasei decreased the symptoms of CRC like diarrhea, rectal bleeding, hair loss, and wasting. A combination of L. paracasei and 5-FU caused a significant decrease in tumor size and number and increase in total apoptotic cells (51.4%) compared to untreated control (2.1%) and DMH (5.9%) groups. Treatment with L. paracasei showed fewer dysplastic changes in the crypts, low grades of dysplasia and less proliferative and metastatic activity into deeper layers in comparison with DMH-only treated group. The lowest AgNOR counts were observed in combined L. paracasei and 5-FU treated group. Anti-apoptotic and apoptosis-inducing genes were downregulated and upregulated respectively in L. paracasei treated rats. The results of the present study suggest that L. paracasei possesses therapeutic potential for decreasing the progression of colorectal cancer and enhance the anti-tumor effects of 5-FU.