The correlation of Kampo formulations and their ingredients on anti-bacterial activities against Propionibacterium acnes.

The correlation between the susceptibilities of Propionibacterium acnes strains to two Kampo formulations and these to their ingredients (Kampo crude drugs) was examined. Two out of 19 Kampo crude drugs, Coptidis Rhizoma (CR) and Phellodendri Cortex (PC), inhibited the growth of P. acnes significantly. The patterns of distribution of the minimal inhibitory concentrations of Keigai-rengyo-to (KRT) and of Seijo-bofu-to (SBT) were almost the same as those of the Kampo crude drugs, except CR and PC. Furthermore, no correlations between MICs of Kampo formulations and those of their ingredients against P. acnes were found. This might be due to mutual inhibition or to differences in anti-bacterial mechanisms between the two Kampo formulations and their ingredients. The Kampo formulations, composed of CR, PC and a few other kinds of Kampo crude drugs, might be more susceptible against P. acnes, since higher concentrations of the effective ingredients can be achieved.