Sturgeon roe-derived tetrapeptide NLPL attenuates oxidative stress associated skin senescence endpoints, accompanied by increased NAD+, improved telomere-associated biomarkers, and enhanced ECM-related readouts

• SRH enhances hyaluronic acid secretion and accelerates scratch closure in H 2 O 2 -challenged HaCaT keratinocytes. • UPLC-MS/MS peptidomics plus in silico prioritization identified NLPL as a representative candidate peptide from SRH. • SRH and NLPL increase collagen III/IV and attenuate senescence-associated endpoints in H 2 O 2 -challenged HSF fibroblasts. • In a D-galactose induced oxidative-stress driven accelerated aging-like mouse model, SRH and NLPL improve skin collagen/HA and systemic redox status. • Intact NLPL is detectable in rat serum after oral dosing, supporting partial uptake and the plausibility of oral activity. Sturgeon roe protein hydrolysate (SRH) was prepared by enzymatic hydrolysis and evaluated for skin-protective activities across epidermal oxidative-injury responses and dermal ECM/senescence-related endpoints. In an H 2 O 2 -challenged HaCaT model, SRH protected keratinocytes against oxidative injury, improved cellular antioxidant status, and enhanced repair-related functions (hyaluronic acid secretion and scratch closure), providing screening-oriented functional justification for downstream peptide mining. UPLC-MS/MS peptidomics coupled with in silico prioritization shortlisted candidate peptides from SRH, and Asn-Leu-Pro-Leu (NLPL) was selected for validation. In an H 2 O 2 -challenged HSF model, SRH and NLPL increased type III and type IV collagen and attenuated senescence hallmarks by increasing relative telomere length and NAD + content while reducing SA-β-gal activity. In a D-galactose-induced oxidative-stress-driven accelerated aging-like mouse model, both interventions increased skin collagen and HA and improved systemic redox status. A rat absorption study detected intact NLPL in serum after oral administration, providing proof-of-concept evidence for partial intact uptake and supporting the plausibility of oral activity. Across most endpoints, SRH outperformed NLPL, which may reflect multi-component effects of the peptide mixture in SRH. Collectively, these results support SRH and NLPL as nutricosmetic candidates targeting oxidative-stress resilience and dermal ECM/senescence-related outcomes associated with skin aging.