A novel water‐in‐oil emulsion with a lecithin‐modified bentonite prevents skin damage from urban dust and cedar pollen

Abstract

OBJECTIVE: Particulate matter (PM), such as air pollutants and pollens, are known to cause skin ageing through skin inflammation. It is important to develop formulations which protect the skin from PM. We previously developed a conventional water-in-oil emulsion with a synthetic surfactant, distearyldimonium chloride, modified bentonite (C-W/O), which protects skin from allergens. In the present study, we developed a novel water-in-oil emulsion with a natural surfactant, lecithin, modified bentonite (N-W/O). METHODS: The microarray analysis was performed using total RNA extracted from a reconstructed human epidermis (RHE) stimulated with urban aerosols or cedar pollen for 6 h in order to develop an epidermal inflammation model by PM for the evaluation of topical formulations. We then compared the efficacy of N-W/O and C-W/O to prevent epidermal degradation. Tissues and culture media were collected 24 h after the urban aerosol or cedar pollen stimulation for a histological assay, and the quantification of MMP1 and IL-8 secretion. RESULTS: The expression levels of proinflammatory cytokines and chemokines, such as IL1A and CXCL8, and matrix metalloproteinases, including MMP1, MMP3 and MMP9, were significantly up-regulated by the PM stimulation. As a result of ranking based on the pathway enrichment analysis, oxidative stress-related pathways, such as MAPK-mediated signalling, HIF-1 signalling, IL-1 signalling and ROS-induced cellular signalling, were ranked high in the urban dust-and cedar pollen-treated groups. A thickened stratum corneum, thinned vital layer and cleaved E-cadherin were observed by haematoxylin and eosin staining and immunohistochemical staining of E-cadherin in the PM treated groups. The secretion of MMP1 and IL-8 into the media was significantly increased by the PM stimulation. N-W/O prevented the degradation of epidermal integrity and secretion of inflammatory proteins more effectively than C-W/O.

Impact of airborne particulate matter on skin: a systematic review from epidemiology to in vitro studies

“…In 3D HEE models, PM usually in concentrations of up to 50 μg/mL was mainly applied topically and short-term exposures (i.e., 24 to 48 h) were performed [128,130,132,133]. PM was shown to affect the physical epidermal barrier in 3D models, as indicated by altered expression of proteins important for epidermal differentiation, such as filaggrin, involucrin, loricrin, and keratins [125,127,129,130,132,133]. Additionally, markers for proliferation, such as Ki67, 5-bromo-2′-deoxyuridine (BrdU) incorporation, and proliferating cell nuclear antigen (PCNA), were shown to be decreased upon PM exposure [125,130].…”

“…CYP enzymes can metabolize PAHs, and the formed metabolites can induce cell damage either by the formation of DNA, protein adducts, or the generation of ROS [195,[204][205][206][207][208]. Indeed, PM upregulates the CYP enzyme mRNA and protein expression in vitro and in vivo [119,128,129,134,135,139,141,167,171,172,178,187]. Other ROS producing enzymes are the members of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) family [209].…”

“…Although most of the studies were carried out using an active ingredient only, protective effects against PM were demonstrated also from finished formulations. For example, a novel water-in-oil emulsion with a lecithin- modified bentonite, applied topically on a HEE 3D model, prevented skin damage from urban dust and cedar pollen, as indicated by the decrease in MMP-1 and IL-8 protein secretion [129].…”

Anti‐pollution skincare: Research on effective ways to protect skin from particulate matter

“…41 Iwanaga et al reported that water-in-oil emulsion with natural surfactant can prevent PM-induced inflammation in a reconstructed human epidermis model. 42 While the mechanism of how PM affects skin remains to be elucidated, Jin et al reported that PM, either through the direct penetration of barrier-disrupted epidermis or through hair follicles in intact skin, causes ROS-dependent inflammation in skin. 19 Therefore, there may be three possible ways to protect the skin from harmful effects Based on previous studies and the above concept, the combination of micellar water and barrier cream or antioxidant was expected to show some clinical benefit in participants who were responsive to PM.…”

Role of proteoglycans on skin ageing: a review

“…It is a genetically determined process that occurs with ageing and is thereby inevitable. This process may be accelerated by environmental factors such as smoking or sun exposure [6][7][8][9], which are factors that are responsible for the so-called extrinsic ageing. Based on these factors [10], we can state that skin ageing is affected by inflammatory factors, hormonal levels, genetic regulation, the production of free radicals [11], exposure to UV radiation, environmental contaminants, etc.…”