# The mechanism of Vicenin-2 in ameliorating skin photoaging: involvement of m6A-modified macrophage polarization

## TL;DR

This study explores how Vicenin-2, a natural flavonoid, reduces skin photoaging by shifting macrophages to an anti-inflammatory state through m6A RNA modifications.

## Contribution

The study reveals a novel mechanism by which Vicenin-2 modulates macrophage polarization via m6A modification and NF-κB signaling in photoaging.

## Key findings

- Vicenin-2 reduces skin damage and improves hydration by promoting M2 macrophage polarization.
- Vicenin-2 upregulates KIAA1429, enhancing m6A RNA methylation and inhibiting NF-κB activation.
- Topical Vicenin-2 treatment shows potential as a new intervention for photoaging.

## Abstract

Skin photoaging is primarily induced by ultraviolet radiation and is closely associated with chronic inflammation and degradation of the extracellular matrix, with an imbalance in macrophage polarization (elevated M1/M2 ratio) being a key factor.

This study first conducted single-cell sequencing analysis to investigate the correlation between macrophage subtypes and photoaging. At the same time, we investigated the effects and mechanisms of the natural flavonoid Vicenin-2 on photoaging through both in vivo and in vitro experiments. In vitro, Vicenin-2 was applied to LPS-induced RAW264.7 macrophages; in vivo, a mouse model of photoaging was established using UVA/UVB irradiation, followed by topical treatment with different concentrations of Vicenin-2 cream.

It was found that in the photodamage model, the infiltration of pro-inflammatory M1 macrophages significantly increased, and the key regulatory factor KIAA1429 was positively correlated with the level of anti-inflammatory M2 macrophages. The results showed that Vicenin-2 significantly alleviated skin damage, improved hydration and collagen organization, and promoted the shift of macrophages from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. Mechanistically, Vicenin-2 upregulated the m6A modification regulator KIAA1429, enhanced overall m6A RNA methylation, and inhibited NF-κB pathway activation by suppressing p65 phosphorylation.

The findings indicate that Vicenin-2 may mitigate skin photoaging by modulating macrophage polarization toward the M2 phenotype through m6A-dependent regulation of the NF-κB signaling pathway, supporting its potential as a novel topical agent for photoaging intervention.