Abstract Background Administration of green tea (GT) catechins has been reported to ensue antitumor activity in combination with chemotherapeutic drugs against different cancer types. Irinotecan (IRN) is a highly effective chemotherapeutic drug against various types of cancer including colon cancer along with its analogous dose-limiting side effects viz. diarrhea, neutropenia, leucopenia, and non-alcoholic fatty liver disease (NAFLD) as major toxicities. Methods In this study, we investigated the antitumor effects of GT alone or in combination with IRN in inflammation-associated colon cancer mouse model induced by azoxymethane (AOM) and dextran sulfate sodium (DSS). We also evaluated the effect of GT- on IRN-induced toxicity and histopathol...