Aim of the study: Bofutsushosan (BTS) is a formula comprising eighteen crude drugs in traditional Japanese Kampo medicine used for obesity and metabolic syndrome. Six type of BTS prescriptions are listed Japanese Pharmacopoeia (JP), and the total amount of crude drug is different for each. It has been reported that activation of interscapular brown adipose tissue (BAT) thermogenesis is involved in lipid metabolism mechanism of BTS. While, recent data suggest that there are two distinct types of brown fat: classical brown fat derived from a myf-5 cellular lineage and UCP1-positive cells that emerge in white fat from a non-myf-5 lineage. In this study, we investigated effect of BTS extracts on lipid metabolism.
Materials and methods: BTS prescriptions were prepared from 27.1 g (BTS-1) or 28.0 g (BTS-2) of crude drugs. Mice were reared with high fat diet containing Kampo extract for 28 days, measured body fat distribution and UCP-1 mRNA expression in inguinal white adipose tissue (WAT).
 Results: The amounts of visceral fat on day 28, and was significantly lower in BTS extract-treated groups. And, The expression of UCP-1 mRNA was significantly elevated in BTS-2 than BTS-1.
Conclusions: BTS has beneficial effect on obesity and metabolic syndrome, and one of its action mechanisms is the promotion for browning of white adipose tissues, and was enhanced by BTS-2. These results suggest that an increase in the amount of crude drug may have a positive effect on the pharmacological action of BTS.