Biological Potential of Grape Skin Extracts: A Comparative Study of Grape Varieties from the Šumadija Region

Abstract

The growing demand for environmentally friendly nutritional and medicinal products has stimulated the research of natural bioactive compounds, especially those obtained from agricultural waste such as grape skins. This study provides an overview of previous findings on the antioxidant and anti-inflammatory activity of grape skin extracts from four grape varieties - Marcellin, Shiraz, Cabernet Franc and Petit Verdot - originating from the Šumadija region. The extracts were obtained using ultrasonic extraction with green solvents: water, ethanol and ethyl acetate. Total phenolic content (TPC) was measured by the Folin-Chocolate method, while antioxidant activity was assessed using the DPPH and ABTS assays. Anti-inflammatory activity was assessed by the lipoxygenase (LOX) inhibition assay. Ethyl acetate extracts showed the highest antioxidant potential. It is noteworthy that GSE5 (Shiraz-ethyl acetate extract) and GSE2 (Marselane-ethyl acetate extract) showed the most significant activity. GSE5 had IC₅₀ values of 24.5 μg/ml (DPPH) and 5.3 μg/ml (ABTS), while GSE2 showed strong reducing power (0.1823 at 700 nm compared to 0.1249 for ascorbic acid). In the LOX assay, GSE5 and GSE2 achieved IC₅₀ values of 15.2 μg/ml and 25.3 μg/ml, respectively. These findings highlight the potential of grape skin extracts as natural agents for managing oxidative stress and inflammation, with applications in the food and pharmaceutical industries.