Elastin and Collagen: Proteins for Suppleness and Firmness.

Elastin is by definition a protein secreted by fibroblasts, the main cells of connective tissue. As a reminder, connective tissue is a support tissue; the dermis, the deepest layer of the skin, is a connective tissue, unlike the epidermis, the most superficial layer, which is an epithelial tissue.

Elastin is a major protein component of tissues found not only in the skin, but also in the lungs, arteries, bladder, elastic ligaments and cartilage. Elastin is synthesized from a soluble precursor called tropoelastin by cross-linking lysine residues using lysyl oxidases. Following this, elastin is made up of soluble tropoelastin, glycine, valine, proline and modified alanine residues.

Elastin's role is to enable various elements of the body to retain their shape even after stretching. It enables elastic skin, meaning its return to its original state quickly after being stretched, pricked or pinched. Thanks to elastin, the skin is perfectly stretchable and better toned.

With the same diameter, elastin is five times more elastic than a rubber band!

However, elastin production by fibroblasts stops at puberty. Although elastin proteins are resistant and difficult to break down, certain enzymes called elastase, also secreted by fibroblasts, are capable of cleaving them and rendering them less effective. As a result, skin loses elasticity and wrinkles deepen.

Elastin as such exists as a cosmetic active ingredient; it is derived from the marine environment, and is therefore referred to as marine elastin, even if the INCI name remains ELASTIN. Nevertheless, products containing elastin are very rare on the market. Instead, we find skincare products containing elastin-boosting active ingredients such as “Calcium 2-cetogluconate”. Elastin is more commonly found in dietary supplements, although there is scientific debate about its effectiveness on the skin after ingestion.

Naturally present in the body, collagen is the most abundant protein in the human organism, accounting for around 25% of all proteins in the body. Manufactured by fibroblasts, it confers mechanical resistance to stretching and structure to many of the body's connective tissues. Collagen is found in skin, muscles, bones, ligaments, tendons, hair and more…

There are 28 types of collagen, with different properties depending on where they are located. Type I is the major component of the extracellular matrix of the dermis, accounting for 80 to 90% of total collagen. It is characterized by three helically organized polypeptide chains, each composed of a thousand amino acids linked by disulfide bridges to form motifs (called sequences). Glycine is the most represented amino acid, but it is also rich in proline and hydroxyproline.

Collagen is of great importance to the skin. Present in fibrous form, it ensures tissue regeneration, provides elasticity, suppleness and resistance, and acts as a binder between skin cells, helping to maintain its structure. The problem is that, as we age, collagen synthesis slows down. This loss can begin around the age of 25, and the body can lose around 1% of collagen per year, gradually increasing to 25% per year. By the age of 80, we have lost 75% more collagen than young adults. What's more, over the years, collagen fibers become rigid, fragmented and disorganized.

These phenomena favor the appearance of wrinkles, loss of tissue firmness and resistance, as well as elasticity of skin. In addition, the lack of collagen in the skin leads to irregular skin texture: the skin loses its radiance and the complexion is less even. Unprotected exposure to UV rays, smoking and atmospheric pollution, not to mention the role of diet in causing glycation (the binding of sugars to collagen), which results in the rigidification of this protein, all contribute to this early degradation of collagen.

To slow down skin aging, external collagen supplements can help. It can be used in cosmetics to compensate for age-related decrease in production, helping to reduce the depth of wrinkles and improve elastic skin appearance. 

But be careful!  In general, collagen used in cosmetics is of animal origin: it is either extracted from beef or pork cartilage, or from the skin, bones, and scales of fish. The INCI name gives no indication of the collagen's origin. You need to contact the manufacturer to find out where it comes from. The collagen used in our wrinkles and loss of firmness serum is of plant origin: it consists of plant fragments of type I collagen, which mimics human collagen and has been transiently generated by wild plants. Nicotiana benthamiana was used as the carrier plant. For this purpose, a synthetic fragment of human type I collagen was cloned and transcribed in vitro, before being inserted into the cytoplasm of plant cells.