Skin Barrier Functions

The functions of the skin to prevent external stimuli and foreign substances, such as allergy-causing substances, bacteria, and viruses, from entering the skin and to prevent evaporation of water from the body are referred to as the skin barrier function.
The skin of atopic dermatitis is naturally prone to dryness, and because the skin barrier function is impaired, it is unable to prevent foreign substances from entering the skin, causing inflammation, itching, eczema, and other symptoms.


A compound composed of iron and porphyrin. It combines with the protein globin to form hemoglobin. Hemoglobin transports oxygen to the body when iron molecules in heme combine with oxygen molecules.


Collagen is one of the proteins that make up the dermis, ligaments, tendons, bones, and cartilage of mainly vertebrates. It accounts for about 30% of all human proteins. It not only works in the body, but is also used in various forms in human life, including foods and cosmetics.
The types of collagen are classified using Roman numerals, such as type I and type II.

TypeⅠ collagen

The collagen is present in the largest amount in vertebrates. It is responsible for the elasticity of bones and the strength of skin.

Impact Factor

An indicator that measures how much influence scientific or social science journal relatively has on its field. It’s also the average number of times a paper is quoted per year in the journals. This has been calculated annually since 1975.There are arguments both pros and cons, however, generally, a bigger numerical value of Impact factor is considered to be evaluated more highly.


It is a compound (tripeptide) of multiple amino acids and is composed of three amino acids: glutamic acid, cysteine, and glycine. It is present in almost all cells in the body and has the function of protecting cells from reactive oxygen species.

In Japan, it is positioned as a pharmaceutical product. It is considered useful for maintaining health and beauty.


A general term for molecules consisting of short chains of amino acids. It is said to be derived from the Greek word “πεπτος“(digestible). A peptide with two amino acids is called a “dipeptide”, a peptide with three amino acids is called a “tripeptide”, a peptide with 10 or fewer amino acids is called an “oligopeptide”, and a peptide with many amino acids linked together is called a “polypeptide”.


Oxidation is a chemical reaction in which the target substance loses an electron. Specifically, it is a chemical reaction in which oxygen is compounded with a substance or a substance is deprived of hydrogen.

Typical examples include rusting of metals, burning of paper and wood, and discoloration of apples. Since organic dyes become colorless by oxidation, oxidants are used as bleaching agents.

Reactive oxygen species

Oxygen and related molecules that are more activated than oxygen in the atmosphere, a general term for highly reactive compounds containing oxygen. They are unstable and react easily with various substances.

In minute quantities, they are useful to the human body, but in large quantities they produce lipid peroxide, which causes arteriosclerosis, cancer, aging, and impaired immune function.


A generic term for substances that inhibit the generation and function of reactive oxygen species or remove reactive oxygen species themselves. Antioxidants include antioxidant enzymes synthesized in the body, such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT), and antioxidants taken in from food, such as polyphenols, carotenoids, and vitamins.