Morin and Morin Semicarbazone Combined with Fucoxanthin Have Potential Anti-Inflammaging Effects Through Modulation of Nrf2/HO-1 System in UVB-Exposed HaCaT Keratinocytes

Abstract

Ultraviolet (UV) radiation is a main environmental factor responsible for skin damage, leading to oxidative stress, inflammation, and impairment of the skin barrier function. Furthermore, many components in sunscreen may accumulate in aquatic systems, causing environmental pollution. Therefore, the identification of novel natural bioactives that counteract these effects and can be useful as effective adjuvants in sunscreen formulations is of particular interest. Morin (1), a natural flavonoid, represents an attractive scaffold for modifications to enhance its biological activity. Herein, we aimed to investigate the effects of combining the flavonoid 1 and its derivative, morin semicarbazone (2), with the carotenoid fucoxanthin (FX) on UVB-exposed HaCaT keratinocytes. All compounds exhibited higher radical scavenging activity compared to Trolox. In this cell model, the phenolic–carotenoid combinations provided greater photoprotection than individual com pounds, significantly enhancing cell viability and reducing necrosis, FX-2 emerged as the most potent combination, as evidenced by a marked reduction in reactive oxygen species (ROS) and malondialdehyde (MDA) levels, likely mediated through the activa tion of the nuclear factor erythroid 2-related factor 2/Heme oxygenase-1 (Nrf2/HO-1) signaling pathway. Furthermore, the tested treatments exerted enhanced anti-inflammatory effects by significantly reducing interleukin-6 (IL-6), cyclooxygenase 2 (COX-2), and matrix metalloproteinase-9 (MMP-9) mediators, with FX-2 being the most active combination. In conclusion, our findings highlight the protective effects of the combinations of these pheno lics with the carotenoid FX against UVB radiation and support their potential application as natural active ingredients in sunscreen formulations.