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Updated: Apr 12, 2026
Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Amentoflavone mitigates UVB-induced epidermal photoaging by antagonizing PAR2-driven PI3K/Akt/FoxO6 oxidative-stress
Lin Li1, Zhiwei Li2, Shan Xiao1
1School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
Abstract:
Escalating surface ultraviolet-B (UVB) radiation accelerates skin photoaging and underscores the need for safe, plant-derived photoprotectants. Amentoflavone (AF), the principal biflavonoid of the resurrection plant Selaginella tamariscina, has recognized anti-photoaging activity, yet its epidermal mechanism remains undefined. This study utilized animal and cellular models to investigate the therapeutic potential of AF (0.1-0.2 mg g-1) against photoaging. AF restored skin hydration and elasticity, reduced melanin deposition, and reversed UVB-induced epidermal hyperplasia and collagen/elastic-fiber disorganisation. AF decreased ROS and MDA while normalizing SOD, CAT and GSH-Px activities. Docking (LibDockScore = 125.596) and microscale thermophoresis (MST) revealed high-affinity AF-PAR2 interaction. Treatment with AF reduced PAR2 and Gαq levels, curtailed activation of PI3K, phosphorylated Akt, and phosphorylated FoxO6, and restored FoxO6 nuclear localization, which in turn enhanced MnSOD and CAT expression. In addition, AF suppressed UVB-induced upregulation of senescence-associated markers p16, p21, and GLB1 in both rat skin and HaCaT cells. However, administration of the PAR2 agonist SLIGRL-NH2 negated these benefits in both cellular and animal models. These findings position AF as a promising natural agent for anti-photoaging dermotherapy and provide a mechanistic basis for S. tamariscina-based product development.
Insights
Amentoflavone (AF) from Selaginella tamariscina protects skin from UVB damage by reducing oxidative stress and inflammation. This plant-derived compound offers a natural approach to combatting skin photoaging.
Area of Science:
- Dermatology
- Plant Biochemistry
- Molecular Biology
Background:
- Ultraviolet-B (UVB) radiation accelerates skin photoaging, necessitating safe, plant-derived photoprotectants.
- Amentoflavone (AF), a biflavonoid from Selaginella tamariscina, shows anti-photoaging potential, but its mechanism in skin is unclear.
Purpose of the Study:
- To investigate the therapeutic effects and epidermal mechanism of Amentoflavone (AF) against UVB-induced skin photoaging using animal and cellular models.
Main Methods:
- Animal and cellular models were used to assess AF's effects on skin hydration, elasticity, melanin, and epidermal structure.
- Biochemical assays measured oxidative stress markers (ROS, MDA, SOD, CAT, GSH-Px).
- Molecular techniques including docking, microscale thermophoresis (MST), Western blotting, and senescence marker analysis were employed.
Main Results:
- AF improved skin hydration, elasticity, reduced melanin, and reversed UVB-induced epidermal changes and collagen disorganization.
- AF decreased oxidative stress and normalized antioxidant enzyme activities.
- AF demonstrated high-affinity interaction with PAR2, inhibiting its signaling pathway and downstream effectors, thereby reducing senescence markers.
Conclusions:
- Amentoflavone (AF) effectively mitigates UVB-induced skin photoaging by targeting the PAR2 pathway and reducing oxidative stress and senescence.
- AF is a promising natural agent for anti-photoaging dermotherapy, supporting the development of Selaginella tamariscina-based products.
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