Different effects of cytochalasins on the growth and differentiation of Entamoeba invadens

Abstract

The effect of five different cytochalasins on the growth, encystation and excystation of Entamoeba invadens was examined. At 10 μM, cytochalasins B, D, E and dihydrocytochalasin B markedly inhibited growth. Encystation was inhibited by cytochalasin D at 1 μM but not by other cytochalasins at the same concentration, whereas it was inhibited by 10 μM of cytochalasins B, E and dihydrocytochalasin B as well as cytochalasin D. Excystation, which was assessed by counting the number of metacystic amoebae after inducing excystation, was markedly enhanced by cytochalasin D as previously demonstrated, whereas the enhancing effect of cytochalasins A, B and dihydrocytochalasin B was weak. In contrast, cytochalasin E at 10 μM inhibited excystation and metacystic development. These results indicate that there is a difference in the effect of different cytochalasins on the growth and differentiation of E. invadens, depending on differences in their chemical structure.