Differentiation-Inducing Activity of the Phyto-polyphenols Epigallocatechin-3-gallate and Kaempferol on NB4 Cells

Background Objective: The rate of survival in acute promyelocytic leukemia (APL) can dramatically improve, if the patients receive all-trans-retinoic acid (ATRA) treatment. However, this drug s toxicity is a major problem in APL treatment. Previous researches have demonstrated that phyto-polyphenols such as epigallocatechin gallate (EGCG) and kaempferol cause apoptosis in hematopoietic neoplasms, but do not negatively impact healthy cells. The present study compared the differentiation effects of kaempferol and EGCG, as well as ATRA in NB4 leukemia cells during five days. Materials Methods: Herein, kaempferol and EGCG s differentiation-inducing activity was examined by NBT assay and Real-time PCR in leukemia NB4 cells. Results: EGCG (25 μM) and kaempferol (50 μM) induced the NB4 cells differentiation, towards a granulocytic pattern similar to ATRA (1 μM). EGCG further suppressed PML/RARα clinical marker s expression compared to kaempferol, it also decreased HDAC1 expression in leukemia NB4 cells. Conclusion: Based on this study, compared to kaempferol, EGCG at low concentrations is preferred for long-term ATRA therapy in APL patients.