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

Abstract

Background: 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.

Objectives: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Keywords: ESETRILLQ peptide; Prinsepia utilis Royle polysaccharides; genetic analysis; placebo‐control; skin barrier; skin radiance.

FIGURE 1

PUR9‐2 highlighted anti‐inflammatory and cell proliferation regulatory regulating genes distinct from PURP and EQ9 when used solely. (a) Differential gene expression in the UVA‐irradiated group. (b) Principal component analysis (PCA) of gene expression levels in the different groups. (c) Heatmap of gene expression levels in the different groups. (d) Functional enrichment analysis of the differentially expressed genes in the PUR9‐2 group compared to the UVA‐irradiated group.

FIGURE 2

PUR9‐2 significantly increased the expression of genes relating to anti‐inflammation and barrier homeostasis. (a–d) The mean value of relative gene expression on LDLRAD4, TNFAIP3, CRNN, and CYP19A1 in control, UVA, EQ9, PURP, PUR9‐1, and PUR9‐2. The results were expressed as mean ± SD. *p < 0.05, **p < 0.01 vs. UVA group. #p < 0.05, ##p < 0.01 vs. UVA group.

FIGURE 3

PUR9‐2 significantly increased the expression of genes relating to epidermal junction. (a–c)The mean value of relative gene expression on FLG, LOR, and DSG1 in control, UVA, EQ9, PURP, and PUR9‐2. The results were expressed as mean ± SD. *p < 0.05, ***p < 0.001, ****p < 0.0001 vs. UVA group.

FIGURE 4

PUR9‐2 showed a synergistic effect in cell migration (CI < 1). (a) Dose–effect curve of PURP, EQ9, and Combo. (b) Combination index plot of PURP and EQ9. (c) Isobologram for 50%, 75%, and 90% effects of Combo.

FIGURE 5

PUR9‐2 containing lotion improved translucency and glossiness of sensitive skin in a placebo‐controlled and split‐face clinical study. (a) The mean value of TEWL. (b) The mean value of K. (c) The mean value of glossiness detected by Glossymeter. (d) The mean value of glossiness detected by VISIA 7. Improvement (%) of Day 7/Day 14 from baseline is also presented. (e–h) The mean value of ITA°, L, a, b. (i) Expert evaluation of glossiness and dullness on subjects' facial skin by the PUR9‐2 lotion group and the placebo lotion group on Day 0 (baseline), Day 7, and Day 14. (Expert evaluation used a nine‐point scale: 0 = best, 1–3 = better, 4–5 = normal, 6–8 = worse, 9 = worst. *p < 0.05 vs. baseline).

FIGURE 6

A lotion containing PUR9‐2 decreases appearance of wrinkls. The mean value of wrinkle number and wrinkle area by PUR9 lotion group and placebo lotion group on Day 0 (baseline), Day 7, and Day 14. Improvement (%) of Day 7/Day 14 from baseline is also presented (*p < 0.05 vs. baseline).