Investigation of Apoptosis-mediated Cytotoxic Effects of Royal Jelly on HL-60 Cells

In recent years, the use of nontoxic natural products that can be effective on cancer cells as new agents has attracted the attention of scientists in order to reduce the negative side effects of existing cancer drugs and their toxicity to normal cells. Some in vivo and in vitro studies have shown that royal jelly (RJ) inhibits cell proliferation and induces apoptosis. In this research, we aimed to investigate the effects of RJ on proliferative and apoptotic processes in the human acute promyelocytic leukemia cell line (HL-60). The HL60 cell line was treated with different concentrations of RJ for 24, 48, and 72 hours. The half maximum inhibitory concentration (IC50) of RJ was determined using 3-(4.5 dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide test (MTT) and the proliferation activity of HL-60 cells was evaluated. Flow cytometry analysis was performed to measure apoptosis in HL-60 cells. IC50 values for RJ were calculated as 13.98, 6.45, and 2.06 mg/mL for 24, 48, and 72 hours, respectively. Flow cytometry results also showed that RJ had apoptotic effects at the concentrations found. The results showed that RJ treatment significantly induced apoptosis and reduced the proliferation of HL-60 cells. This study shows that RJ can be a complementary treatment against HL-60 acute myeloid leukemia cells due to its anticancer and antiproliferative effects.