At the early stage of infection, TNF-α, IL-1β and IL-6 showed an increasing trend with both Entamoeba species, but with higher levels with E. histolytica than with E. nuttalli. The increased TNF-α and IL-6 during amebic tissue damage results in activation of macrophages to release NO and thereby exert an anti-inflammatory effect. This evidence concerns the gene IL1B and infection.