Cosmetic products with high affinity to the skin have been recently studied, applying liposome and nanosized capsules formed by amphiphiles such as lecithin and other lipids to them. Sphingolipid, based on the sphingosine framework among the said lipids, is one of new bio-lipids which have begun to be studied in terms of physicochemical/biological properties and applicabilities. Sphingomyelin is known as a representative sphingophosphohpid. In this study, we tried to use this sphingomyelin as a cosmetic ingredient, particularly for a liposomal formula consisting of the sphingomyelin. As a result, it was found that its barrier (occlusive) ability against water evaporation was superior to that of lecithin as a representative glycerophospholipid, due to a higher rigidity in the bilayer membrane of the liposome. Therefore, it is expected that sphingomyelin will show a complementary effect for damaged intercellular lipid structures of the stratum corneum when it is applied to skin care products. In addition, it was demonstrated that a skin care product with sphingomyelin had a high moisturizing/emollient ability and an improvement effect on existing wrinkles.

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Lighting can change the appearance of the skin in a major way. Taking notice of the fact that illumination with enhanced red content is often used to make skin look more attractive, we evaluated the effect of long wavelength light on the appearance of the skin. We developed a light source that could emit light in any combination of wavelengths, and used a variety of lights against the skin to conduct a visual evaluation. As a result, we found that skin that was illuminated with light containing a large percentage of long wavelength light of at least 600nm appeared even in tone, with skin faults such as spots and fine wrinkles rendered less visible. Next, we evaluated the light reflected from the skin. As a result of an evaluation of spectral reflectance and skin appearance, we found that as little as a 10% increase in the reflectance of long wavelength light contributed to the enhancement of an even appearance of the skin. We therefore considered methods for incorporating this “flattering effect” to make the skin appear better than it actually is into the development of cosmetic products. We engaged in the development of powdered material that would generate the same kind of reflectance as would be generated by illumination with red light. As a result, we came to develop a red powdered fiber with a #-shaped cross-section. This material, with its unique cross section, demonstrated an effect of enhancing only the reflectance of long wavelength light, without lowering lightness or chroma. We verified that when this powder was formulated into a sample foundation and applied to the skin, the skin appeared more even in tone and looked more attractive compared to skin to which conventional foundation was applied.

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Spectral reflection curves of human skin generally show a characteristic dip in the 500 to 600nm range. This “dip” is unique for each person, and is believed to be caused by the spectral absorption of blood. We investigated the spectral reflectance of human skin and discovered a very interesting correlation between the area of the reflectance dip and L value (lightness of the skin). The Standard Area of Reflectance Dip (ADs) is defined and calculated from the correlation we discovered. The Actual Area of Reflectance Dip (ADa) is calculated from the spectral reflection curve. The ratio of ADa and ADs was found to be a very useful optical parameter for skin complexion perception. By artificially creating different optical environments and varying ADa/ADs from 10% to 200%, we found that skin appeared more beautiful when ADa/ADs was in the 100-125% range. We therefore considered methods for applying these results into the development of cosmetic products. Investigation and testing of many different pigments resulted in the development of specially-designed powdered fiber with a #-shaped cross section dyed magenta. An experimental foundation with this powdered fiber produced a clear reflectance dip by raising reflectance in the short and long wavelength ranges. ADa/ADs increased from 49% to 107% without reducing lightness when this makeup foundation was applied on sallow skin.

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In a recent study, stimulating the formation of anchoring fibrils at the basement membrane zone in skin contributed to preventing skin ageing, such as wrinkle formation. Expression of the type VII collagen gene induces the formation of anchoring fibrils composed mainly of collagen type VII. We therefore transiently transfected a keratinocyte cell line with the plasmids containing type VII collagen gene promoter located upstream of the luciferase gene. We investigated the promoter activity under the presence of flavonoids and we found that Genkwanin up-regulates the transcriptional activation of human type VII collagen gene promoter.

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Hydrolyzed proteins and silicones have been widely used and played an important role in hair treatment. Effects on hair, of a newly developed hybrid polymer consisting of hydrolyzed protein, alkyl chain and silicone was investigated. It was clear that the polymer was effective in preventing dyed hair from discoloring and in improving the moisture feel of hair. It was confirmed that the polymer had good substantivity contributing to hair luster, manageability, moisture feel, smoothness and good combability. The above effects were remarkably displayed especially on damaged hair. Furthermore, a sensory test in practical use of shampoo even with the polymer highly diluted supported the above results.

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