皮膚常在優勢菌(Staphylococcus epidermidis)のスーパーオキシドジスムターゼ(SOD)分泌を促進する化粧水(Mn/Zn含有)を用いた皮膚へのSOD送達法

抄録

Superoxide dismutase (SOD) has been recognized as an attractive component not only for dermal anti-inflammation medicaments but also for cosmetics to scavenge and detoxicate superoxide (O₂^-), a very highly active oxygen species to the skin cells or its sebum layer when exposed to the sunshine (especially UV-A wave range). However, the wide application of SOD is still limited in development because of its cost for the large scale production and its unstable nature in formulation. Our recent study concerning the relationship between human skin and its resident bacterial flora revealed that the first abundant (10^3-4 cfu/cm²) aerobic bacteria group, Staphylococcus epiclermidis, possessed the highest SOD activity/cell among frequently detectable skin resident bacterial species including transient bacteria (Propionibacterium acnes, Micrococcus sp., Streptococcus sp., Staphylococcus aureus, Bacillus sp.). The first abundant anaerobic bacteria (10^4-5 cfu/cm²), P. acnes, showed SOD activity only 1/120 of that of S. epidermidis in cell extract but negligible extracellular excretion of it. The SOD production of S. epidermidis was found to be enhanced by the addition of Mn/Zn ions to the culture medium and its excretion as well. Furthermore, it was found that the secreted SOD suppressed the peroxidation of squalene in vitro under UV-A irradiation. These findings suggested that an unique tool to use skin resident bacteria as a skin care cosmetic machinery to produce and deliver bacterial SOD freshly and effectively toward the skin cell surface and lipid layer on the skin surface surrounding the bacterial cells simply by the application of cosmetic lotion containing Mn/Zn ions.