311 Niacinamide reduces in vivo inflammatory response due to skin barrier disruption

Abstract

Introduction: Impaired skin barrier function has been suggested to underlie sensitive skin. Sensitive skin triggers such as surfactant irritation or mechanical abrasion result in barrier damage and skin inflammation. In subjects with darker skin types, inflammation will also often result in the formation of post-inflammatory hyperpigmentation (PIH). In-vivo efficacy of niacinamide against inflammation caused by barrier damage has not yet been demonstrated. Objective: The goal of the clinical study and ex vivo studies was to understand the role of niacinamide in reducing inflammation and skin tone changes induced by barrier disruption. Materials and Methods: In this single center, randomized, single blinded study a provocation method was executed to mimic sensitive skin response to washing. In this 8-week study, 20 Chinese females were asked to perform the provocation method with or without niacinamide product. Skin chromophores and structure were assessed using CM2600D and the reflectance confocal microscopy (RCM), respectively. Tape stripping samples were obtained for lipidomic analysis. Results: It was found that the barrier disruption followed by washing with a cleansing bar leads to structural skin changes and impacts various skin chromophores. Niacinamide significantly protected skin chromophore changes at multiple timepoints and maintained normal epidermal thickness. Lipidomics analysis confirmed increased expression of various inflammatory lipids which were significantly reduced by niacinamide. Conclusions: Barrier disruption leads to dynamic changes on phenotypical and biological endpoints. Niacinamide showed significant protective effects for various inflammatory end points as well as PIH development and recovery.