Objective To study the protective effects of 5-methoxytryptamine-α-lipoic acid salt(MLA), a new synthetized compound, on the hematopoietic system of mice exposed to sublethal dose of total body irradiation(TBI).

Methods Fifteen C57BL/6 mice were randomly assigned into three groups:control, irradiation, and MLA+irradiation. The mice in the control group received sham TBI, whereas the mice in the other groups underwent exposure to 6.0 Gy ¹³⁷Cs γ-ray TBI. The mice in the MLA group were first administered with 10 mg/kg MLA after exposure to 6.0 Gy TBI for 2 h. The MLA was administered successively for 3 d. The peripheral blood and bone marrow nucleated cells(BMNCs) were then counted after the mice were exposed to TBI for 30 d. The CFU-GM ability, reactive oxygen species(ROS) levels, and nicotinamide adenine dinucleotide phosphate oxidase 4(NOX4) expression in the hematopoietic cells were also detected.

Results In contrast to those of the control group, the number of BMNCs and the number CFU-GM in the irradiated groups decreased significantly(t=9.304, 7.493, both P＜0.05), and the ROS levels and the NOX4 expression in the bone marrow cells of the irradiated groups increased(t=14.74, 53.12, both P＜0.05). Compared with those of the irradiation group, the number of white blood cells and the number of BMNCs were elevated by MLA(t=4.858, 3.947, both P＜0.05). The ROS levels and NOX4 expression in the bone marrow cells were inhibited by MLA(t=11.21, 33.93, both P＜0.05). Conclusion MLA can protect mice from hematopoietic injury induced by irradiation.