According to a new Chanel patent application, Sestrins (SESNs) are recently identified proteins, of which three types are found in mammals: SESN1, SESN2 and SESN3. They were first discovered as genotoxic or oxidative stress-inducible genes that, in response to stress, reduce intracellular ROS.
For example, in human reconstructed skin, SESN expression is modulated after UV exposure, implicating their role in oxidative and UV-induced stress response. Besides these activities, genetic studies have shown Sestrins to regulate metabolic homeostasis.
No apparent study has yet investigated the expression profile, role and function of Sestrins in healthy human skin. It was therefore the focus of the present work to explore their potential to ultimately provide products or actives that prevent, reduce or even inhibit skin cell damage and aging, and/or improve skin hydration and/or skin pigmentation.
Method to identify an apply Sestrin activators for anti-aging, hydration and pigmentation benefits
U.S. Patent Application 20170275694
Publication date: Sept. 28, 2017
Assignee: Chanel Parfums Beauté
According to this patent application, SESN1, SESN2 and SESN3 show specific expression profiles in human epidermis and epidermal derived keratinocytes that vary with cellular differentiation status, age and UV exposure. Furthermore, Sestrin deficiency in epidermal keratinocytes impacts autophagy and cell differentiation markers.
In addition, SESN1, SESN2 and SESN3 genes are expressed in normal human melanocytes and their expression is modulated after UVA or UVB irradiation. Thus, compounds that regulate their expression could impact the cellular response toward environmental stress.
This invention thus discloses a method to identify compounds that can regulate the expression of at least one Sestrin gene for effects including preventing and/or attenuating skin aging, hydrating the skin and regulating skin pigmentation.
Specifically, said method comprises: a) bringing at least one test compound in contact with human keratinocytes or melanocytes; b) measuring the expression of at least one Sestrin gene chosen from SESN3, SESN2 and SESN1 in the keratinocytes or melanocytes; and c) selecting the compounds for which an activation of at least 1.6-fold is measured.
In various embodiments of the present invention, botanical extracts were explored; including Solidago (goldenrod) extract, which was shown to stimulate the expression of SESN1 and SESN3; and fenugreek, which stimulated SESN3.