# Natural Bioactive Peptides from Tree Peony Flowers: Multifunctional Effects on Skin Antioxidation, Wrinkle Reduction, Moisturization, and Melanin Inhibition

## TL;DR

Tree peony flower protein hydrolysate shows multiple skin benefits including antioxidant, anti-wrinkle, moisturizing, and whitening effects.

## Contribution

The study identifies and characterizes 54 bioactive peptides from tree peony flowers with multifunctional skin health benefits.

## Key findings

- TPFP inhibited UVB-induced ROS and restored antioxidant enzyme activities in skin cells.
- TPFP protected pro-collagen I, suppressed MMP-1, and increased hyaluronic acid for anti-wrinkle and moisturizing effects.
- TPFP reduced melanin synthesis by downregulating tyrosinase-related proteins in melanoma cells.

## Abstract

The edible tree peony (Paeonia suffruticosa Andrews) flowers are rich in bioactive components with potential health benefits, but the skin-health-promoting effects of their protein hydrolysates remain understudied. The present research sought to evaluate the antioxidant, anti-wrinkle, moisturizing, and whitening properties of tree peony flower protein hydrolysate (TPFP). TPFP was prepared via enzymatic hydrolysis and ultrafiltration, and its peptide sequences were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), revealing 54 unique small-molecule peptides with an average amino acid length of 8.2 residues and a molecular weight of 914.51 Da. In vitro safety evaluation using CCK-8 assay showed TPFP (20–100 μM) did not induce substantial cytotoxic effects in either HaCaT keratinocytes or B16F10 melanoma cell lines. Functional assays demonstrated that TPFP dose-dependently inhibited UVB-induced reactive oxygen species (ROS) overproduction and restored superoxide dismutase (SOD) and catalase (CAT) activities in HaCaT cells, exerting antioxidant effects. Additionally, TPFP protected pro-collagen I from UVB-induced loss, suppressed the expression of matrix metalloproteinase 1 (MMP-1), and restored hyaluronic acid (HA) content, showing anti-wrinkle and moisturizing potentials. In α-MSH-stimulated B16F10 cells, TPFP suppressed melanin synthesis by downregulating the protein expression of tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and TRP-2, achieving a whitening effect. These findings indicate that TPFP possesses comprehensive skin-health-promoting activities with good biocompatibility, highlighting its potential as a natural functional ingredient in cosmetics and functional foods.