How to Predict AGEs Accumulation Slowdown Effect of a Cosmetic Ingredient? Two Steps <i>In-Vitro</i>System for Evaluating the Anti-AGE Impact of a New Blend

Advanced Glycation End-Products (AGEs), play a crucial part in advancing the process of cellular skin aging and its link to chronological age was re-assessed. AGEs accumulation alters cell structure and function of most types of skin cells, affecting skin’s mechanical and physiological properties, following the molecular transformations. Slowdown AGEs accumulation rate in skin, although a potent anti-aging strategy, is difficult and tricky. The lack of working methods for In-Vitro and In-Vitro measuring AGEs level complicates the evaluation and prediction of active ingredients’ ability to affect cellular AGEs accumulation. A two-step In-Vitro systematic screening method is proposed and three different cosmetic active ingredients were selected for its demonstration, using BSA-Glucose and Collagen-Glucose predicting models. Candidates’ effects on AGEs accumulation were evaluated as standalone, and when formulated in a blend. Additionally, the potency of non-invasive auto-fluorescence in-vivo measurement to detect AGEs levels among subjects of different ages was demonstrated. The results are presented in this work and the potential contribution of the proposed system to assist the desired inhibition of AGEs accumulation in skin is discussed.

Nrf2 Pathway Involvement in the Beneficial Skin Effects of Moderate Ionic Osmotic Stress—The Case of The Dead Sea Water

Objectives: Exposing skin to moderate ionic osmotic stress (MIOS) triggers several biochemical responses. The objective of this work is to reveal the mechanism triggered by MIOS on the skin surface. Furthermore, this work aims to study the involvement of the Nrf2 (nuclear factor erythroid-2-related factor 2) pathway, activated by MIOS, and its beneficial effect in protecting skin against stress via the stimulation of phase II enzymes. Methods: HaCaT cells and human skin organ culture were exposed to Dead Sea Water (DSW) as MIOS inducers and the induction of internal ROS elevation, Nrf2 translocation, mRNA gene expressions of the phase II enzymes, heme-oxygenase 1 (HO1), and Catalase (CAT) were determined. Results: Skin exposure to MIOS increases Nrf2 translocation to the nucleus, leading to increased levels of ROS, HO1, and CAT. Furthermore, exposing skin to MIOS promotes protection against UVB-related risks. This is demonstrated by attenuation of the expression of biomarkers, related to UVB-induced damage, Caspase-3, IL-8, and IL-1β. Conclusions: Skin exposure to MIOS leads to the activation of Nrf2 skin defense pathway and, therefore, could present beneficial advantages to human skin health, as demonstrated on human skin models. The beneficial effects of MIOS, induced by DSW are significantly superior to eq. NaCl brine, suggests that MIOS protection of skin against stress is partially related to specific mineral combinations.