<jats:title>Abstract</jats:title><jats:sec><jats:title>BACKGROUND</jats:title><jats:p><jats:bold>Stevioside is a natural non‐caloric sweetener isolated from <jats:italic>Stevia rebaudiana Bertoni</jats:italic> leaves. We have proposed its effect on attenuation of tumour necrosis factor α (<jats:styled-content style="fixed-case">TNF</jats:styled-content>‐α) and interleukin 1β (<jats:styled-content style="fixed-case">IL</jats:styled-content>‐1β) release in lipopolysaccharide (<jats:styled-content style="fixed-case">LPS</jats:styled-content>)‐stimulated monocytes. In this study, the anti‐inflammatory and immunomodulatory activities of stevioside and its metabolite, steviol, on human colon carcinoma cell line (Caco‐2) were evaluated</jats:bold>.</jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p><jats:bold>Stevioside and steviol, in the doses used in this study, had no cytotoxicity on Caco‐2 cells. Anti‐inflammatory activities of these two compounds were observed by potentially suppressed <jats:styled-content style="fixed-case">LPS</jats:styled-content>‐mediated <jats:styled-content style="fixed-case">TNF</jats:styled-content>‐α, <jats:styled-content style="fixed-case">IL</jats:styled-content>‐1β and <jats:styled-content style="fixed-case">IL</jats:styled-content>‐6 release. In addition, stevioside and steviol showed immunomodulatory effects on <jats:styled-content style="fixed-case">IκBα</jats:styled-content> activation and nuclear factor kappa B (<jats:styled-content style="fixed-case">NF‐κB</jats:styled-content>) suppression in western blotting</jats:bold>.</jats:sec><jats:sec><jats:title>CONCLUSION</jats:title><jats:p><jats:bold>Stevioside and steviol attenuate <jats:styled-content style="fixed-case">LPS</jats:styled-content>‐induced pro‐inflammatory cytokine productions by affecting cytokine gene expression via <jats:styled-content style="fixed-case">IκBα</jats:styled-content>/<jats:styled-content style="fixed-case">NF‐κB</jats:styled-content> signalling pathway. © 2013 Society of Chemical Industry</jats:bold></jats:sec>