MPO and colonic neoplasm: During the current study, the elevation in MPO activity colon cancer induced group attributed to the inflammatory effect of AOM that was generally associated with oxidative stress (Lowes et al., 2013) and / or due to the neutrophil infiltration that is linearly related to the MPO activity that increased as a result of effect of DSS ingested in combination with AOM (Pandurangan et al., 2015).