Disruptive Effect of Epigallocatechin-3-Gallate on the Proliferation/Apoptosis Balance in the Olfactory Epithelium

ABSTRACT

The polyphenol epigallocatechin-3-gallate (EGCG), is the main active catechin of the green tea. It exerts a wide range of biochemical and pharmacological effects on different animal cells. EGCG acts as a scavenger of growth factors and it was demonstrated its antiproliferative and proapoptotic role in different cancer cells. Nevertheless, little is known about the effect of EGCG on normal cells. In the present work, we have studied the EGCG effect on the proliferation/ apoptosis balance in the olfactory epithelium of amphibian tadpoles. Animals treated with EGCG showed an increase in the number of apoptotic cells and a decrease in the basal proliferation. In addition, EGCG showed differential effect on the two classical growth factors signalling pathways, MAPK and PI3K route. EGCG treatment triggered a drop in phospho- ERK1/2 level without affecting the phospho-AKT level. These findings demonstrate the antiproliferative and proapoptotic effect of EGCG on normal olfactory cells and postulate the olfactory epithelium as a good experimental model for the study of the factors involved in neurogenesis process.