Melanin overexpression causes skin hyperpigmentation, which is associated with various skin disorders and cosmetic concerns. Umbelliferone, a natural coumarin found widely in plant species, has been noted for its antioxidant and anti-inflammatory effects but has received little attention for its impact on melanogenesis. Here, the effects of umbelliferone on melanogenesis were investigated in vitro and in clinical studies. The results showed that umbelliferone was non-cytotoxic to human skin and B16F10 melanoma cells. It also exhibited significant anti-melanogenic effects, reducing both melanin production and tyrosinase activity in a dose-dependent manner. This effect was achieved through a decrease in tyrosinase mRNA levels. Furthermore, umbelliferone in a formulation was stable under different temperature conditions, and after four weeks of topical application, it significantly decreased the melanin index and increased skin lightness (L*) values compared to those at the baseline. Overall, these findings demonstrate the potential of umbelliferone as a promising skin-lightening agent in the cosmetics industry.

Polydeoxyribonucleotide (PDRN), a DNA fragment mixture, exerts biological effects via adenosine A2A receptor and salvage pathway activation. Here, Paeonia lactiflora-derived PDRN (Peony PDRN) is proposed as a plant-based alternative to salmon-derived PDRN. While P. lactiflora is known for its medicinal properties, the biological functions of Peony PDRN have not been characterized. To validate and optimize its efficacy, we systematically compared the biological activities of three molecular weight groups of Peony PDRN (high, medium, and low) using in vitro assays and clinical studies. The low-molecular-weight fraction (Low-Peony PDRN) markedly enhanced skin cell proliferation and migration, upregulated extracellular matrix-related genes (COL1A1, COL5A1, ELN, and FBN1), and promoted keratinocyte differentiation and epidermal barrier formation by increasing COL7A1, IVL, FLG, and OCLN expression. It also reduced reactive oxygen species levels and suppressed key inflammatory mediators. Clinically, topical application of Low-Peony PDRN for 2 weeks markedly reduced transepidermal water loss in a sodium lauryl sulfate-induced skin damage model, enhancing barrier recovery (n = 10). Periorbital skin elasticity improved after 4 weeks of treatment (Approval No. Intertek IRB-202505-HR(1)-0001, 20 June 2025). These results indicate that Low-Peony PDRN is a promising plant-derived biomaterial of pharmacological and cosmetic significance, with potential to address skin aging.

Saussurea involucrata, commonly known as snow lotus, is a rare medicinal plant that is traditionally used in several countries owing to its therapeutic properties. Snow lotus extracts have been shown to exert anti-inflammatory effects and reduce reactive oxygen species levels. Although various bioactive compounds have been identified in snow lotus, the biological activity and underlying mechanisms of DNA isolated from this plant remain unexplored. This study aimed to investigate the skin-regenerative properties of polydeoxyribonucleotide (PDRN) isolated from snow lotus. PDRN was extracted and purified from dried flowers of S. involucrata. Water-soluble tetrazolium salt 1, wound healing, and enzyme-linked immunosorbent assays were used to evaluate the effects of snow lotus PDRN on cell proliferation, cell migration, and collagen synthesis, respectively. We also measured matrix metalloproteinase 1 (MMP1) mRNA expression after snow lotus PDRN treatment. Snow lotus-derived PDRN was non-cytotoxic to human skin cells and significantly promoted cell proliferation and migration. Additionally, it enhanced collagen synthesis by suppressing the expression of MMP1. These findings demonstrate that snow lotus PDRN may be a promising anti-aging agent and may serve as a valuable ingredient in cosmeceutical formulations.