Development of skin health test efficacy modules in vivo

Abstract

Sunlight contains ultraviolet (UV) light that causes sunburn and makes the skin age faster, leading to more wrinkles as older. The UV light can come from the natural and artificial sources. Moreover, UV light has shorter wavelengths than the visible light. Therefore, people’ eyes can’t see UV, but people’ skin can feel it. In this study, the in vivo skin health test efficacy modules have been established via the detection of skin’s moisture retention (%), skin’s cytokine expression levels, enzymatic expressions in the skin, the expression levels of hyaluronic acid (HA), collagen type I, melanin, and malondialdehyde (MDA) in the skin, and the experimental mice’ skin thickness and lesions via histo-pathologic examination. According to the results, the clinical behavior observation indexes of Institute of Cancer Research (ICR) mice in each group were normal during the experiments. Moreover, all ICR mice were survival until the end of the experiments. The moisture retention (%) of skin in ICR mice in UVB group was significant decrease after D1, D3, and D5 of UVB irradiation compared to the normal control group. Based on the IL-1β, IL-6 and TNF-α analysis expressions, both IL-1β and IL-6 expressions in UVB group were significantly increase than the control group, while there was no significant difference in the TNF-α expression between the groups. ICR mice’ skin enzymatic expressions in each group presented that catalase (CAT) expression and superoxide dismutase (SOD) activity in UVB group were significantly lower than the control group. The MDA expression in UVB group were significantly higher than the control group. The HA and collagen type I expressions in UVB group were significantly lower than the control group. However, the melanin expressions in UVB group and the control groups were not significantly different. The matrix metalloproteinase 2 (MMP-2) expressions in UVB group was significantly higher than the control group. The skin epidermal thickness in UVB group was significantly thicker than the control group. The dermal thickness in two groups was not significantly different. The number of sunburn cells in the derma in UVB group was significantly increase than the control group. The solar elastosis in the derma in two groups was not significantly different. Based on the above results, we have successfully established in vivo skin health test efficacy modules to evaluate the status of skin health. We hope the modules should be provide for the research and development (R&D) of the effective treatment included drugs and therapeutic strategies.