Protective effects of an aqueous extract from Pinctada fucata martensii mucus on ultraviolet A-induced skin photoaging: in vitro and in vivo evidence

Abstract

Ultraviolet A (UVA) radiation is a primary extrinsic driver of skin photoaging, yet effective marine-derived photoprotective countermeasures remain underexplored. The Akoya pearl oyster ( Pinctada fucata martensii, Pinctada martensii ) mucus represents a largely underexplored source of water-soluble marine natural products. In the present study, a low-molecular-weight aqueous fraction (designated AKN) was prepared via direct aqueous extraction and 3 kDa ultrafiltration without enzymatic hydrolysis, preserving the native constituent profile. AKN was systematically profiled using orthogonal untargeted LC–MS and targeted compositional analyses, with taurine and betaine accounting for 8.0% and 4.1% of the dry weight, respectively. Its biological effects were evaluated in UVA-exposed L929 murine fibroblasts, LPS-stimulated BV2 murine microglial cells, and a UVA-induced BALB/c mouse skin photoaging model, using ergothioneine (EGT) as a positive control. In cellular assays, AKN markedly suppressed the expression of key senescence regulators ( p16, p21, p53 ), attenuated pro-inflammatory mediators ( Tnf, Il6, Il1b ), and reduced intracellular reactive oxygen species. In mouse skin, topical AKN restored Col1a1 transcription and improved histological architecture by suppressing epidermal hyperplasia and collagen depletion, with 4 mg/mL AKN providing pronounced protection alongside 4 mg/mL ergothioneine. Overall, these findings establish P. martensii mucus as a promising source of natural, hydrolysis-free photoprotective agents and support further bioassay-guided identification of its primary active constituents.

The authors' abstract, as published at the source. Frontiers in Natural Products, 2026 · DOI ↗