DNA damage and protective effects of placental extracts in blood lymphocytes and lymphoid organs of mice exposed to gamma irradiation

Abstract

DNA damage was evaluated in blood lymphocytes and lymphoid organs including lymph nodes, bone marrow, spleen and thymus of C3H/He N mice exposed to gamma irradiation. Furthermore, the protective effects of placental extracts (PE) on DNA damage were determined. Mice were exposed to gamma irradiation (high dose of 7 Gy, 137Cs, 0.8 Gy/min) with or without PE treatment and comet assays were performed to determine DNA damage occurring in the lymphocytes, lymph nodes, bone marrow, spleen and thymus of mice. In the pre- and post-gamma irradiation exposure groups, the Olive tail moments of blood lymphocytes and lymphoid organs were significantly increased, compared with controls. The highest DNA damage was revealed in lymphocytes, and the lowest in bone marrow. Post-gamma irradiation exposure with intramuscular injected PE significantly decreased DNA damage in blood lymphocytes and lymph nodes, but pre-gamma irradiation exposure with PE significantly decreased DNA damage in blood lymphocytes, lymph nodes, and bone marrow. No change of DNA damage was found in non-irradiated PE treatment groups. Taken together, the present study suggests that acute gamma radiation exposure induced significant DNA damage and PE can attenuate this damage in blood lymphocytes and lymphoid organs of mice.