Effects of Kampo Formulations (Chinese Herbal Medicine Traditionally Used in Japan) on Event-Related Electric Potentials

Abstract

Contingent negative variation (CNV) is a brain function test of the central nervous system in reference to attention, will preparation and motivation. We compared the neuropharmacological effects of 6 main Kampo formulations (1. Mao-to: : MA HUANG TANG; 2. Shimbu-to: : ZHEN WU TANG; 3. Ninjin-to: : REN SHEN TANG; 4. Shigyaku-san: : SI NI SAN; 5. Keishi-to: : GUI ZHI TANG; and 6. Shimotsu-to: : SI WU TANG) on CNV. Mao - to induced significant decrease of CNV in 90 minutes after oral administration. Shimbu - to showed a tendency to increase CNV in 90 minutes after oral administration. Shimotsu-to also induced a transient tendency to increase CNV in 60 minutes after oral administration. Keishi-to showed a decrease of CNV in the early stage of the experiment, while Ninjin - to and Shigyaku - san showed no changes of CNV. From these, it may be concluded that Mao - to and Keish i- to induce sedation of brain function, but Shimbu-to and Shimotsu-to show activation, while Ninjin-to and Shigyaku-san show no changes of brain function regarding CNV related brain function. Furthermore, the time courses of CNV changes were different within the same group (sedation or activation) of Kampo formulations.