Bioactive Effects by Air Microbubble Bathing

Abstract

Microbubbles are tiny bubbles with a 1–100 µm diameter. Their chemical and physical properties are different from those of normal bubbles. One important characteristic of microbubbles is that they are electrically charged at the gas–water interface (ʽζ-potential). Microbubble bathing is believed to decrease sympathetic nervous system activity and stimulate the parasympathetic nervous system via bioactive effects. The parasympathetic nervous system is stimulated when we feel relaxed, and relaxation is important for improving depression. Therefore, recovery of energy via microbubbles can be used as antidepression treatment. In this study, the bioactive effects of microbubbles produced by two types of microbubble generators (slit type and pressurized dissolution type) is investigated. Furthermore, the relationship between ζ-potential and restoring vitality is evaluated. We estimated the stress-coping effect on the basis of the serum globopentaosylceramide (GPC) levels. GPC is a biochemical marker of vitality. Microbubbles generated by the slit-type microbubble generator showed a higher ζ- potential at the gas–water interface compared to those generated by the pressurized-dissolution-type microbubble generator. The shrinkage rate of microbubbles generated by the slit-type microbubble generator was less compared to the pressurized- dissolution-type microbubble generator, indicating that self-shrinkage is affected by the ζ-potential. Restoration of vitality significantly increased via microbubbles generated by the slit-type microbubble generator. In addition, microbubble bathing increased serum GPC levels; also, using the slit-type microbubble generator significantly increased serum GPC levels.