Structure and Function of Ceramide and Its Application in Diseases

About 50% of the lipid components in the human epidermis are ceramides, which, together with cholesterol and free fatty acids, constitute the lipid matrix in the stratum corneum. Ceramide plays an important role in skin barrier function, which can keep skin moist and protect skin from the external environment. Because of the diversity of long-chain bases and fatty acids in structure and chain length, there are many kinds of ceramides, which are often combined by two systems in naming. As an important sphingolipid in the human body, there are three main synthetic routes of ceramide: de novo synthesis, sphingomyelin hydrolysis and remedial route. Studies have shown that ceramide has complex functions in organisms. It is not only an important component of skin stratum corneum lipid but also the second messenger of the apoptosis-related signal pathway, and it also plays a certain role in metabolism and neurological function. Therefore, this paper sorts out the existing literature to help understand the relationship between ceramide and various diseases and hopes to provide new ideas for the prevention and treatment of diseases.