The modulating effect of royal jelly consumption against radiation-induced apoptosis in human peripheral blood leukocytes

The present work was designed to assess the radioprotective effect of royal jelly (RJ) against radiation-induced apoptosis in human peripheral blood leukocytes. In this study, peripheral blood samples were obtained on days 0, 4, 7, and 14 of the study from six healthy male volunteers taking a 1000 mg RJ capsule orally per day for 14 consecutive days. On each sampling day, all collected whole blood samples were divided into control and irradiated groups which were then exposed to the selected dose of 4 Gy X-ray. Percentage of apoptotic cells (Ap %) was evaluated for all samples immediately after irradiation (Ap(0)) and also after a 24 h postirradiation incubation at 37°C in 5% CO(2) (Ap(24)) by the use of neutral comet assay. Concerning Ap(0), collected data demonstrated that the percentage of apoptotic cells in both control and irradiated groups did not significantly change during the study period. However, with respect to Ap(24), the percentage of apoptotic cells in irradiated groups gradually reduced during the experiment, according to which a significant decrease was found after 14 days RJ consumption (P = 0.002). In conclusion, the present study revealed the protective role of 14 days RJ consumption against radiation-induced apoptosis in human peripheral blood leukocytes.