Antioxidant Effects of Porphyra tenera Extract on H2O2-Induced Oxidative Stress in Human Epidermal Keratinocytes

다국어 초록 (Multilingual Abstract)

Skin is constantly exposed to various harmful stimuli, including oxidative stress. Porphyratenera (commonly known as laver, nori, or gim) is an edible seaweed rich in bioactivecompounds with potential benefits for skin health. In this study, we investigated theprotective effects of a water extract of P. tenera extract (PE) on human epidermal keratinocytessubjected to oxidative stress. PE exhibited no cytotoxicity up to 100 μg/mL; therefore,its effects were evaluated within this concentration range. PE significantly reducedintracellular reactive oxygen species levels in the dichlorofluorescin diacetate assay followinglipopolysaccharide (LPS) stimulation and completely restored the decreased activities ofsuperoxide dismutase and glutathione peroxidase in cells treated with LPS or hydrogenperoxide (H2O2). Moreover, PE prevented the downregulation of nuclear factor erythroid 2–related factor 2 (Nrf2) and heme oxygenase-1 and suppressed the increased phosphorylationof c-Jun N-terminal kinase (JNK) and p38 in H2O2-treated cells. Collectively, these in vitroresults demonstrate that PE exerts strong protective effects against oxidative stress in skinkeratinocytes, supporting its potential application as a functional ingredient for skin-healthsupplements.