The effect of bathing with NY-008 (3-octylphthalide, a newly synthesized vasodilative compound) on skin temperature was examined. The subjects were 28 healthy male adults (22±4 years old). The group bathed for 10min in 40°C water containing 3ppm of NY-008. On alternate days, the group bathed similarly but without NY-008 (control bathing). Skin temperature (Ts), blood pressure, and heart rate (HR) were then measured in a room in which the ambient temperature was maintained at 24°C and relative humidity at 60%. To eliminate any effect of diurnal fluctuations in skin temperature, each subject bathed at the same hour each day. Measurements were performed in random order by the double-blind method. The mean values of Ts after bathing were slightly higher after NY-008 bathing than after control bathing, and a significant difference was noted 10min after bathing (p<0.01). There was no significant difference in systolic blood pressure between NY-008 bathing and control bathing. Diastolic blood pressure was slightly lower after NY-008 bathing. Mean blood pressure, measured 5 min after bathing, was significantly lower after NY-008 bathing than after control bathing (p<0.05). No significant difference was found in HR. These findings suggest that NY-008 bathing increases skin blood flow through vasodilation of skin vessels and lower peripheral resistance, and may have longer lasting warming effects than ordinary bathing.

The effects of artificial alum bathing and sodium bicarbonate bathing on the surface tension of skin and sweat were examined.
Before and after partial bathing in distilled water (control), alum solution, or sodium bicarbonate solution at 40°C for 10 minutes, the critical surface tension of skin was measured in a room in which the ambient temperature was maintained at 23°C and relative humidity at 50%. The mean value of critical surface tension decreased after the alum bathing at concentrations of 10, 100, and 1, 000ppm., but did not change after the control and sodium bicarbonate bathing.
Alum solution, sodium bicarbonate solution, or sodium hydroxide solution was added to the sweat collected from the arm skin surface. Its surface tension was then measured in the same room as mentioned above. The mean value of surface tension increased after the sodium bicarbonate preparation and the sodium hydroxide preparation accompanying the increase in the pH value, but did not change after the alum preparation. The surface tension of sweat at pH 7.0 was significantly higher in the sodium bicarbonate preparation than in the sodium hydroxide preparation (p<0.05).
These findings suggest that the alum bathing lowers the wettability of the skin surface and that the sodium bicarbonate bathing lowers the surface activity of sweat. It is suggested that both of these bathings change the skin surface condition and cutaneous function.

The effect of octylphthalide (OP) bathing was compared with placebo bathing on patients with rheumatoid arthritis (RA).
A liquid containing octylphthalide was dissolved in water of 40°C at a concentration of 10ppm. A liquid which has quite similar appearance and perfume to the above was used as a placebo. Double blind controlled study tests were performed.
Twenty patients (10 for OP bathing and 10 for placebo bathing) were tested by single bathing, 33 other patients (16 patients for OP bathing and 17 for placebo bathing), by serial bathing for 30 days (once a day).
After a single bathing, while grip strengths, tender joints scores, and 20m walking time improved significantly in the OP bathing group, only tender joint scores and 20m walking time improved significantly in the placebo bathing group.
After serial bathing for 30 days, tender joint scores improved significantly in the OP bathing group, but no improvement was observed in the placebo bathing group. The above results suggest that OP bathing may be beneficial for RA patients, but further study may be needed.

Using a highly concentrated CO₂-bathing, authors studied an effect of the bathing (CO₂: 1, 000ppm, for 10min at 40°C) on circadian blood pressure in six cases of antihypertensive drug-refractory hypertension. The patients were females, ranging from 62 to 70 years old (mean age: 65.8±2.6). All of the patients were diagnosed as the III stage of essential hypertension (according to WHO criteria) and have been treated with captopril, nifedipine or α-methyl DOPA since three to ten years ago. Out of six cases five showed non-dipper pattern in circadian blood pressure. All bathings were done at 16:30 and comparative study of circadian blood pressure between plain water and CO₂-bathing was carried out.
The results obtained were as follows.
1) In five cases of non-dippers CO₂-bathing exerted the therapeutic effect upon the high blood pressure at night and resulted in the significant decrease in hyperbaric indici of systolic, mean and diastolic blood pressure, comparing with plain water-bathing. However, no significant difference of heart rate was observed between plain water and CO₂-bathing.
2) In a case of good responder to antihypertensive drug, a relatively low blood pressure continued all day after CO₂-bathing.
From these results it is expected that a highly concentrated CO₂-bathing is useful as supportive therapy to essential hypertension, specially to non-dipper.