Natural Phytotherapeutics in Dermatology and Cosmetology: Bioactive Potential of Grape Pomace on Human Skin Fibroblasts

The aim of the study was to assess the biological potential of extracts obtained from the grape pomace of three <i>Vitis vinifera</i> hybrid varieties-Regent, Rondo and Marechal Foch-as a natural source of bioactive compounds, with possible application in cosmetology and dermatology. Grape pomace, which is an important by-product of the winemaking process, is a rich source of polyphenols, flavonoids, anthocyanins and vitamin C, which exhibit antioxidant, anti-inflammatory and cytoprotective properties that are important for skin health. The conducted studies determined the antioxidant activity of the extracts (DPPH) and the content of total phenolic compounds, flavonoids, anthocyanins and vitamin C, Of the varieties analysed: Marechal Foch exhibited the highest antioxidant activity (10 µmol TE/g), while Regent demonstrated the highest flavonoid content (50.42 mg/g) and vitamin C content (35.6 mg/100 g). The Rondo extract had the highest content of anthocyanins (362.36 mg/g) and total phenolic compounds (18.31 mg/g), indicating strong protective potential for skin cells. Regent extract at a concentration of 25 μg/mL was found to have the greatest effect on fibroblast proliferation and migration, significantly increasing the percentage of living cells and the rate of regeneration. This correlates with the high flavonoid content, which is particularly important for skin cells. These results confirm that grape pomace, particularly from the Regent variety, is a valuable source of natural antioxidants with anti-aging and regenerative properties. The use of these raw materials in cosmetic formulations aligns with the principles of the circular economy and the idea of "zero waste", being an example of the sustainable use of by-products from the wine industry in the production of innovative bio-cosmetics.