In this study, we investigated the effect of bathing with cut crude drugs on thermal preservability, water holding capacity, and smoothness of the feel. After immersion with cut crude drugs of 5min at 41°C, the forearm skin core temperature was significantly higher than after plain water bathing. Water sorption-desorption tests on the skin in vivo with cut crude drug extract for the functional assessment of the stratum corneum revealed that the GARENIAE FRUCTUS extract, all of cut crude drugs extract, and FOENICULI FRUCTUS extract are significantly superior to plain water bathing in water holding capacity.
Furthermore, an evaluation using a skin model revealed that cut crude drugs have effects significantly superior to that of plain water bathing in increasing the smoothness of the feel. The above results clarified that bathing with cut crude drugs has a stronger effect on thermal preservability and that their extract increases water holding capacity and smoothness of the feel.

The effects of bathing with inorganic salts and carbon dioxide (ISCD) on body temperature, systemic circulation, food ingestion and absorption have been studied in healthy volunteers. The peripheral blood flow in the forearm was found to increase in and after immersion of the forearm into a 25l bathing receptacle containing ISCD, as compared with plain water. The peripheral blood flow tended to increase in a dose-dependent manner with ISCD bathing. The skin core temperature, the skin surface temperature and the peripheral blood flow were significantly higher after ISCD bathing than after plain water bathing. The influences of ISCD bathing on food ingestion and absorption were also studied in healthy volunteers. Blood glucose and insulin levels after food ingestion tended to be suppressed by ISCD bathing as compared with plain water bathing. There was no difference between ISCD and plain water bathing in total protein, total cholesterol, triglyceride, HDL cholesterol, and uric acid levels in the blood. These results suggest that ISCD bathing may contribute to the promotion of human health.