Differential ratios of fish/corn oil ameliorated the colon carcinoma in rat by altering intestinal intraepithelial CD8+ T lymphocytes, dendritic cells population and modulating the intracellular cytokines

Intraepithelial lymphocytes (IELs) impart a crucial role in maintaining intestinal homeostasis, yet their role in colon cancer pathogenesis remains unknown. Here, we posited that the modulation of intestinal immune response via dietary interventions might be an implacable strategy in restraining colon carcinoma. In the above context, we studied the effect of differential ratios of fish oil (FO) and corn oil (CO) on the gut immune response in experimentally induced colon cancer. Male Wistar rats were divided into six groups: Group I obtained purified diet while Groups II and III were fed on the diet supplemented with differential ratios of FO and CO i.e. 1:1 and 2.5:1, respectively. The groups were further subdivided into control and carcinogenic group, treated with ethylenediaminetetraacetic acid (EDTA) or N,N’-dimethylhydrazine dihydrochloride (DMH), respectively. Initiation phase comprised the animals sacrificed 48 h after the last injection whereas, the post -initiation phase was constituted by animals sacrificed 12 weeks after the treatment regimen. CD8+ T cells, CD8/αβ TCR cells, dendritic cells increased significantly on treatment with DMH as compared to control. However, on treatment with differential ratios of FO and CO these cells decreased significantly. The intracellular cytokine i.e. interferon gamma (IFN-γ) and cytotoxic granules component i.e Perforin and Granzyme decreased significantly in the initiation phase but in the post-initiation phase IFN-γ and Perforin increased considerably on carcinogen treatment as compared to the control group. On treatment with FO and CO in the initiation phase the IFN-γ, Perforin and Granzyme expression increased significantly. However, in the post-initiation phase treatment with differential ratios of FO and CO led to a significant decrease in the IFN-γ, Perforin and increase in Granzyme was observed in these groups. Altogether, FO supplementation appeared to activate the immune response that may further attenuate the process of carcinogenesis, in a dose and time-dependent manner.