Ferment-derived HA complex aids skin health

Hyaluronic acid (HA) has been one of the most popular polysaccharides to appear in personal care products in the last decade.1,2 The molecule was originally isolated from Rooster combs where it was available in significant amounts and at high molecular weight.3 However, it has now been found that several microorganisms can produce appreciable quantities of the glucosaminoglycan also at high molecular weights.4 In addition, with the discovery of Hyaluronidase (a key enzyme that breaks down high molecular weight HA), it is now possible to commercially create various molecular weight fractions of HA from very high (1.5-2 Million Daltons (MDa*)) to very low (5-20 Kilo Daltons (kDa)).5

Today, the topical benefits of HA are widely known and recognised by scientists and consumers. HA is renowned for its water-binding capabilities and is often suggested to be able to bind many times its weight in water molecules— but this behaviour is keenly dependent on the HA’s molecular weight.6 The human body itself manufactures HA and it has been suggested that the body may contain nearly 0.02% hyaluronic acid as a function of total body mass—but over a third of it is lost daily.7 HA is found in the vitreous humors of the eye, in the cartilage of the bones and most importantly, it is abundant in the dermis, epidermis and in small amounts in the stratum corneum. Along with the components of the skin’s Natural Moisturizing Factor (NMF), HA is a critical element for maintaining the skin’s natural hydration.8

Aside from its ability to bind water, HA has an ability to also signal skin cells. This ability to transmit cellular messages appears to be molecular weight dependent— with lower molecular weight fragments able to penetrate to skin cells to create messages, while higher molecular weight portions signal cellular responses by contacting receptor proteins that are embedded in the skin cell membranes like small HA-focused antenna. One transmembrane protein that HA binds to is called Extracellular Matrix-III (ECM-III) (also known as the Hyaluronate Receptor protein) that is an important Cell Adhesion Molecule (CAM)9-10 (Figure 1). This important protein is responsible for numerous physiological effects that are triggered when the HA molecule interacts and binds to specific sites on the Hyaluronate Receptor. These binding sites are also known to have some molecular weight dependence. It is important to keep in mind that high molecular weight HA that might be applied topically would unlikely be able to penetrate the living epidermis. So, these high molecular weight HA polysaccharides must be created within the viable dermis and epidermis of the skin to be able to bind to the ECM-III proteins. On the other hand, lower molecular weight fragments of HA are known to be able to penetrate to the viable epidermis where they can interact with the keratinocytes in the skin via the ECM-III proteins.11-12