A Marine-Derived Sterol, Ergosterol, Mitigates UVB-Induced Skin Photodamage via Dual Inhibition of NF-κB and MAPK Signaling.

BACKGROUND

Ultraviolet B (UVB) radiation induces oxidative stress, inflammation, and collagen degradation in skin, leading to photodamage. Ergosterol (ERG)-a sterol widely distributed in fungi and algae, including numerous marine species-possesses antioxidant and anti-inflammatory activities, but its photoprotective mechanisms remain unclear.

METHODS

Using integrated in vitro (UVB-irradiated human keratinocytes) and in vivo (topical ERG in a murine UVB model) approaches, combined with transcriptomic and network pharmacology analyses, we evaluated ERG's effects on oxidative stress, inflammation, and extracellular matrix integrity.

RESULTS

ERG treatment preserved keratinocyte viability, reduced reactive oxygen species, and suppressed pro-inflammatory mediators after UVB exposure. In mice, topical ERG significantly attenuated epidermal hyperplasia, maintained tight-junction integrity, and inhibited collagen matrix degradation. Mechanistically, ERG exerted dual inhibition of the nuclear factor kappa B (NF-κB) pathway, which mediates inflammation, and the mitogen-activated protein kinase (MAPK) pathway, which regulates collagen degradation.

CONCLUSIONS

These findings identify ERG as a marine-derived sterol with potent photoprotective activity that simultaneously targets oxidative stress, inflammation, and extracellular matrix damage, highlighting its promise as a natural compound for dermatological applications and aligning with ongoing efforts to explore marine-derived agents against skin oxidative stress and inflammation.