It is thought that highly reactive oxygen radicals generated at the ischemia-reperfusion in case of strokes play an important role in damaging the brain. It is well known that lipid peroxidation is propagated by active oxygen radicals, and the the brain is susceptible to the lipid peroxidation. In the previous study, we found that several Chinese herbal medicines and kampo components, which were used for the attenuation of the post-ischemic brain injury, showed a free-radical (OH·, O2∸ and DPPH) scavenging activity. However, it is not clear whether these Chinese herbal medicines can inhibit the lipid peroxidation reaction or not. In attempting to address this question, we have used three kinds of kampo formulations (Oren-gedoku-to (Huang-Lian-Jie-Du-Tang), Saiko-ka-ryukotsu-borei-to (Chai-Hu-Jia-Long-Gu-Mu-Li-Tang) and Keishi-bukuryo-gan (Gui-Zhi-Fu-Ling-Wan)) to measure the suppressive effect of the lipid peroxidation on the mouse cerebrum using the TBA technique in vitro and in vivo. In vitro experiments, all these Chinese herbal medicines decreased the levels of TBA-reactive substances concentration-dependently. In vivo studies, the levels of the TBA-reactive substance of the cerebrum homogenate of mice treated with these kampo formulations by p.o. for three weeks also decreased. From these results, we suggest that the pharmacological action of Chinese herbal medicines used for the attenuation of the post-ischemic brain damage not only have a free-radical scavenging activity, but also have a suppressive effect on the generation of the lipid peroxidation.
