Fujifilm elucidates the cause of rough skin caused by humidity differences.Discovers the effect of tea leaf extract on improving skin barrier function.

Fujifilm announced that it has clarified the cause of rough skin caused by stimulation due to a decrease in humidity (hereafter referred to as humidity differential stimulation). In addition, they discovered that tea leaf extract has the effect of promoting the expression of acylceramide-producing enzymes, which are important barrier-related factors in the stratum corneum.

While there are many people who suffer from skin problems due to the change of seasons and the wearing and removal of masks, there has not been much research into the mechanism by which such environmental changes cause rough skin.

Fujifilm focused on the "humidity difference" that occurs when the season changes and when the mask is put on and taken off, and worked on research to clarify the effect it has on the skin.

Human skin consists of epidermis and dermis, and stratum corneum, which consists of stratum corneum cells and intercellular lipids, exists in the uppermost layer of the epidermis. Approximately 50% of intercellular lipids in the stratum corneum are composed of ceramide and acylceramide, which form a lamellar structure in which layers are stacked to exert the skin barrier function.

In particular, acylceramide has the function of arranging ceramides in an orderly manner and forming a strong structure, and is known to be an important factor in maintaining barrier function.

Skin Barrier Function and Ceramide

Acylceramide has low solubility and is easy to crystallize, so it was difficult to efficiently penetrate between stratum corneum cells. Succeeded in dispersing. It was confirmed that this ingredient repairs the lamellar structure and improves the barrier function of the skin.

■Details of research results

1. Development of humidity control culture equipment

Biological samples such as cells and epidermis models are usually cultured at high humidity (around 90% RH (*1)) to prevent the evaporation of medium components required for culture. Until now, most of the experiments in which epidermal models were exposed to low humidity and cultivated were carried out by methods such as using desiccants or removing humidifying bats from incubators, and rigorous humidity control was not carried out.

The company has developed a humidity control culture device that can create air with any humidity by mixing dry air and saturated steam.

Mechanism of Humidity Control Incubator

By using this device, it became possible to specify the desired humidity and time, and expose the epidermis model to humidified air for cultivation.