Apoptosis, Cell Cycle and Differentiation Effects of Propolis Extracted in Olive Oil on HL-60 AML Cells: A Flow Cytometric Analysis.

In recent years, researchers have focused on the drug capacity of natural products and their components with low side effects in the treatment of leukemia. This study aims to elucidate the antileukemic mechanism of action of olive oil extract of propolis (OEP) together with methylprednisolone (MP) in HL-60 cells, an acute myeloid leukemia cell line. The WST-8 kit was used to test the cytotoxic and proliferative effects of OEP on HL-60 cells. Flow cytometry was additionally applied for determining apoptotic status, cell cycle, and differentiation levels (CD11b, CD14, and CD68). The IC50 concentration of OEP in HL-60 cells was determined to be 0.5 μ L/mL after a 24 h period. OEP effectively arrested the cell cycle at the G2/M phase after 24 h, and its addition of MP strengthened this effect. After 48 h, OEP significantly inhibited the cell cycle at the G2/M phase. The combination of OEP with MP led to significantly greater numbers of cells arrested in the G0/G1 phase. OEP alone has shown significant efficacy in encouraging apoptosis; however, its combination with MP provided considerably more beneficial effects. The OEP performed efficiently at CD11 levels for the first 24 h. Due to its impact on apoptosis, cell cycle arrest, and differentiation, OEP may be a natural product that merits additional preclinical investigation in leukemia models. The combined effects of OEP and MP on stopping the cell cycle provide a possible way to treat leukemia. Additional research is required to investigate the processes underlying the improved efficacy of the combo-therapy.