A Novel Antioxidant Peptide Cath‐Np Derived from Nanorana parkeri Attenuates UVB‐Induced Skin Photodamage in Mice

ABSTRACT The frog skin‐derived antioxidant peptides have great potential for relieving injury caused by ultraviolet B (UVB) radiation, and have therefore attracted increasing attention. However, the research on these peptides is far from sufficient. This study characterized a new antioxidant peptide, Cath‐Np (AGGKKECKDYYCRLLTKLGSRGHISGVDL), from the skin of Nanorana parkeri . Cath‐Np possessed strong ABTS + and 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging, potassium ferricyanide reducing, and DNA‐protecting effects. Cath‐Np was also able to reduce the abnormal elevation of reactive oxygen species and neutrophil migration in zebrafish. Notably, Cath‐Np significantly reduced the oxidative damage, inhibited inflammatory factor production by suppressing the activation of mitogen‐activated protein kinase and p53 while activating the Nrf2 signaling pathways, and consequently exerted a protective effect against skin photodamage in UVB‐irradiated mice. Hence, our results help to better understand the adaptation mechanism of N. parkeri to the extreme environmental conditions of the Qinghai–Xizang Plateau. Meanwhile, they also highlight the potential application of Cath‐Np as a protective agent against damage caused by UVB radiation and offer a novel candidate molecule for developing anti‐photodamage drugs and cosmetic products.