Physiological Doses of Volatile Organic Compounds Emitted by the Skin under Psychological Stress Impact Skin Functions

Abstract

Background: A previous in vivo study analysing the volatilome—the complete set of volatile organic compounds (VOCs) emitted by an organism—identified 17 compounds that were increasingly released by the skin during psychological stress. Objective: As stress is known to accelerate skin ageing, and many VOCs have detrimental effects on the skin, we selected three of the 17 identified VOCs and assessed their effects following a single exposure to physiological doses. Materials and methods: Using reconstructed human epidermis, we focused on changes in the expression of genes and proteins related to inflammation, epidermal differentiation, and oxidative stress. Results: Each of the three VOCs induces changes in gene and protein expression. Two VOCs, heptadecane and 2,6,10,14-tetramethylpentadecane, induce inflammation and affect epidermal differentiation, although the specific markers influenced and the timing of these changes differ between the two compounds. The third VOC, 2-hydroxyethyl acetate, inhibits inflammation but increases the expression of genes and proteins involved in epidermal differentiation and oxidative stress defence. Conclusion: While each VOC has distinct effects, all impact functions critical to the proper functioning of the skin. These findings suggest that stress-modulated skin VOCs could be a, yet, unsuspected factor linking the brain and the skin and impacting skin functions.