Potential Skin Health Benefits of Abalone By-Products Suggested by Their Effects on MAPKS and PI3K/AKT/NF-kB Signaling Pathways in HDF and HaCaT Cells

Abalone, a marine edible gastropod with nutritional value, is a popular seafood delicacy worldwide, especially in Asia; however, viscera by-products are generally discarded during processing. Therefore, we investigated the skin health benefits of abalone viscera ultrasonic extract (AVU) in human dermal fibroblasts (HDFs) and human keratinocyte (HaCaT) cells. AVU showed valuable protein contents, indicating that it is a worthy and safe material for industrial application. AVU increased collagen synthesis production and messenger RNA (mRNA) expression of Collagen Type I Alpha 1, 2, and 3 chains through the transforming growth factor beta/suppressor of mother against the decapentaplegic pathway in HDF cells. AVU also increased hyaluronic acid production, upregulated Hyaluronan Synthases 1, 2, and 3, filaggrin and aquaporin3 mRNA levels, and downregulated hyaluronidase mRNA levels in HaCaT cells. Furthermore, mechanistic studies showed that AVU increased the phosphorylation of extracellular signal-regulated kinase, p38, and cyclic AMP response-binding protein activation. AVU activated the transcription factors, phosphoinositide 3-kinase, protein kinase B, and nuclear factor kappa B cell p65 and downregulated the degranulation of inhibitory kappa B in HaCaT cells. Studies of hyaluronic acid production in AVU by inhibiting EKR, p38 and NF-κB have shown that p38 MAPK and NF-κB signaling are pivotal mechanisms, particularly in the AVU. These results demonstrated that AVU produced from by-products may improve skin health and may thus be used as a functional food and cosmetics ingredient.