Aging is an ineluctable process affecting all of us, wherever we live or whoever we are. Cells lose their functionality altering progressively the skin quality and function. Visible signs appear, such as wrinkle and skin sagging. We look less healthy, less happy and more tired, finally leading to a diminution of self-esteem and social attractiveness.
In a world where we want to feel good whatever our age and where social interactions are more important than ever, NAGASE Personal Care offers Glucosyl Naringin, a new solution to attenuate visible signs of aging.
Naringin is a natural polyphenol found in citrus fruits peel. Its strong antioxidant activity and valuable biological actions should have made it a perfect candidate for cosmetics. However, its low water solubility has hindered its biological activity evaluation as well as its cosmetic formulation, setting it aside from the cosmetic field.
Convinced of the potentiality of naringin for cosmetic application, the Nagase group company Hayashibara upgraded naringin using its enzyme technology. Indeed, by adding a glucose to the naringin molecule, the solubility of the resulting glycosylated naringin increased from 0.03 g/100g of water to more than 200 G/100g of water. This natural and water soluble active appears as a yellowish powder and is stable from pH 4 to 6, making it easily formulable and evaluable for beneficial biological effects. Its action on skin wrinkles and sagging, the main visible signs of skin aging, could be assessed.
Loss of skin elasticity and firmness and so, of resistance to gravity over the years, is recognized as one of the main causes of wrinkle appearance and skin sagging. Dermal fibroblasts shed their capacity to produce the elements necessary to elastin fibers formation, which are essentially responsible for skin mechanical properties and resilience. To this intrinsic process, environmental factors such as UV and pollution actively alter the existing elastic fibers, amplifying the consequences.
Glucosyl Naringin (at 1%) actively improves the elastin fiber formation by fibroblasts (Fig 1).
To explain this effect, the main elements involved in the elastin protein production and fibers formation process, the elastogenesis (Fig 2), were investigated.
The treatment with GN increases the gene expression of tropoelastin, the precursor of elastin, as well as of Lysyl Oxidase (LOX), the enzyme responsible for protein cross-linking and fiber formation. As a result, the elastin protein content itself is increased. Importantly, this effect appears dose dependent (Fig 3).
These promising results were the starting point of a set of various objectivation tests including in vitro evaluations using 3D skin models, Atomic Force Microscopy and Second Harmonic Generation microscopy, and a clinical study. These data, confirming the utilization of GN to boost skin firmness, are available on request.