Studies on chemical protectors against radiation. XXXV. Effects of radioprotective Chinese traditional medicines on radiation-induced lipid peroxidation in vivo and in vitro.

The fluctuation of lipid peroxidation (LP) in 9 tissues was investigated in mice for 7 d after whole-body X-irradiation with a lethal dose of bone marrow death. LP increased significantly in bone marrow, thymus, spleen and liver following irradiation, and slightly in brain and testis, but not in blood plasma, submaxillary gland or kidney. The effects of 7 radioprotective Chinese traditional medicines (CTMs) and cysteamine (MEA) on the radiation-induced LP in 4 tissues were studied by i.p. injection before or after irradiation and their LP content in tissues was measured 2 d after irradiation. Most CTMs showed significant inhibition of radiation-induced LP in bone marrow and liver, especially when injected prior to irradiation. Some CTMs also showed such inhibition in spleen. MEA only inhibited the increase of LP in liver when injected before irradiation, but enhanced the increase of LP in spleen. None of these radioprotectors including MEA was recognized to inhibit radiation-induced LP in thymus. The in vitro experiments were carried out using mouse liver microsomal suspensions (MS). The MS were prepared from normal (non-irradiated) mice. Each of the 8 radioprotectors was added to MS before or after irradiation and then post-irradiation-incubated at 37 degrees C. All markedly inhibited radiation-induced LP if added before irradiation, but were slightly less effective if added after.