Vitis vinifera L. Leaves as a Source of Phenolic Compounds with Anti-Inflammatory and Antioxidant Potential

Vitis vinifera is a plant known since ancient times mainly for the interest of its fruits. However, its leaves have traditionally been consumed as food in some regions of the Mediterranean basin and as a medicinal remedy. In this work, the phytochemical profile of this part of the plant, which is considered a bio-residue of viticultural processes, was analyzed (UHPLC-ESI(±)-QTOF-MS). Hydroxybenzoic acids, flavonols, and stilbenes are the main phenolic compounds identified. Its antioxidant and anti-inflammatory capacity were studied both in vitro and in cell culture. Grapevine leaves have a high capacity to scavenge free radicals, as well as to reduce oxidative stress induced by H₂O₂ in the HepG2 cell line. On the other hand, the methanolic extract of these leaves is capable of inhibiting lipoxygenase, an enzyme involved in inflammatory responses, with an IC₅₀ of 1.63 μg/mL. In addition, the extract showed potent inhibition of NO production in LPS-stimulated RAW 264.7 cells. These results pointed out V. vinifera leaves as a powerful functional food with a high content of biologically active compounds. The enhancement of these by-products can be highly beneficial to food systems and contribute to the development of sustainable agriculture.