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Updated: Jul 8, 2025

Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
β-endorphin suppresses ultraviolet B irradiation-induced epidermal barrier damage by regulating
Hyung-Su Kim1, Hyoung-June Kim1, Yong-Deog Hong1
1Amorepacific Research and Innovation Center, Yongin, Gyeonggi-do, 17074, Korea.
Abstract:
Solar ultraviolet B (UVB) radiation triggers excessive inflammation, disrupting the epidermal barrier, and can eventually cause skin cancer. A previous study reported that under UVB irradiation, epidermal keratinocytes synthesize the proopiomelanocortin-derived peptide β-endorphin, which is known for its analgesic effect. However, little is known about the role of β-endorphin in UVB-exposed skin. Therefore, in this study, we aimed to explore the protective role of β-endorphin against UVB irradiation-induced damage to the skin barrier in normal human keratinocytes (NHKs) and on a human skin equivalent model. Treatment with β-endorphin reduced inflammatory responses in UVB-irradiated NHKs by inactivating the NF-κB signaling pathway. Additionally, we found that β-endorphin treatment reversed UVB-induced abnormal epidermal proliferation and differentiation in NHKs and, thus, repaired the skin barrier in UVB-treated skin equivalents. The observed effects of β-endorphin on UVB-irradiated NHKs were mediated via blockade of the Akt/mTOR signaling pathway. These results reveal that β-endorphin might be useful against UVB-induced skin injury, including the disruption of the skin barrier function.
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