# Synergistic Enhancement of Compromised Skin Radiance: A Clinical Investigation of Prinsepia utilis Royle Polysaccharides and Nonapeptide Co‐Application

## TL;DR

This study investigates how combining a natural extract and a peptide can improve skin radiance and repair compromised skin.

## Contribution

The novel contribution is demonstrating the synergistic effect of Prinsepia utilis Royle polysaccharides and EQ9 peptide in enhancing skin radiance and barrier function.

## Key findings

- The combination of PURP and EQ9 significantly improved skin glossiness and translucency in clinical trials.
- The combination enhanced gene expression of skin barrier-related proteins like FLG, LOR, and DSG1.
- The treatment reduced TEWL by 16.96%, indicating improved skin barrier function.

## Abstract

Skin radiance represents both healthy and esthetic aspects of human skin, usually influenced by a compromised barrier and the aging process. The reduction of the stratum corneum by chemical peels is a prevalent procedure employed to enhance facial radiance, but peeling is not suitable for compromised skin.

Prinsepia utilis Royle polysaccharides (PURP) is a natural extract with repairing properties, which has been reported as a barrier repairing agent. ESETRILLQ (EQ) peptide has been recently reported as a novel antiaging bioactive peptide. This study aims to investigate the combined efficacy of these two ingredients on skin radiance enhancement.

Reconstructed human full‐thickness skin models were subjected to UVA exposure, followed by treatment with 1000 ppm PURP, 20 ppm EQ9, and their combinations: PUR9‐1 (1000 ppm PURP + 10 ppm EQ9) and PUR9‐2 (1000 ppm PURP + 20 ppm EQ9). Transcriptomic profiling was performed as a preliminary study to define the synergistic effect. RT‐qPCR was performed assessing the regulation of skin barrier‐related genes. Thirty‐three Chinese sensitive skin individuals were enrolled in a placebo‐controlled split‐face clinical research for 2 weeks to evaluate a PUR9‐2 containing lotion. Instrument measurement and expert evaluation were conducted to evaluate the parameters of glossiness and skin tone at baseline, Day 7, and Day 14. Skin glossiness was determined by VISIA 7, Glossymeter, and Translucency Meter. TEWL was determined by Tewameter Hex. Wrinkel number and area were obtained by VISIA 7.

Transcriptomic profiling identified PUR9‐2 to regulate significantly different genes distinct from PURP and EQ9. The combination increased the gene expression levels of TNFAIP3 and CRNN. PUR9‐2 also increased the expression of FLG, LOR, and DSG1on UVA‐irradiated skin model. PUR9‐2 containing lotion significantly decreased TEWL by 16.96%. Clinical evaluations demonstrated a statistically significant 22.32% (Glossymeter) and 35.56% (VISIA 7) improvement in skin glossiness on the PUR9‐2 lotion‐treated side by Day 14 compared to baseline. Translucency demonstrated a statistically significant 13.06% increase of K value, which all aligned with the expert evaluation of skin radiance enhancement.

PCA analysis revealed PUR9‐2 uniquely modulated gene expression compared to PURP and EQ9. Functional enrichment analysis based on Gene Ontology (GO) demonstrated PUR9‐2 restored UVA‐suppressed TNFAIP3 and CRNN gene. The results of RT–PCR also indicated that PUR9‐2 enhanced skin barrier integrity in 3D models via upregulated expression of FLG, LOR, and DSG1. The Chou‐Talalay method further validated PUR9‐2's synergistic potency (CI < 1) in accelerating keratinocyte scratch wound closure. The clinical research demonstrated protective effects of PUR9‐2 on compromised skin barrier and enhanced both glossiness of the sensitive skin surface and translucency within the skin structure. This study provides a potential solution for improving the radiance and overall conditions of compromised skin.