Hydroethanolic Extract of Grape Peel from Vitis labrusca Winemaking Waste: Antinociceptive and Anti-Inflammatory Activities

Research background. Extracts from grape pomace, including the wine, showed many biological effects such as antioxidant and anti-inflammatory activities. Unfortunately winemakers discard the bagasse and the waste is less useful, however it contains bioactive compounds which result in antioxidant and anti-inflammatory properties. The work aimed to analyze the hydroethanolic extract of peels from agro-industrial waste from Vitis labrusca and to evaluate its antinociceptive and anti-inflammatory assays. This study is relevant for reusing a residue and adding value to the grape economic chain. Experimental approach. A representative sample of pomace was obtained and the peels were applied to produce the extract. The phenolic compounds were determined by multiple reaction monitoring mode of mass spectrometry methods and Folin-Ciocalteu, using gallic acid as standard. The biological analyzes were carried out using mice orally treated with crude extract at doses (30, 100, and 300 mg/kg). We evaluated mechanical hyperalgesia by the von Frey method, thermal heat hyperalgesia using a hot plate at 55 °C, paw edema using a pachymeter, and neutrophil recruitment by measurement of myeloperoxidase enzyme activity. The nephrotoxicity and hepatotoxicity were evaluated by biochemical analyses using blood samples that were collected after the Vitis labrusca administration. Results and conclusions. The peels correspond to 75 % of all wet winemaking residue and 59 % on a dry basis. We identified nine anthocyanins (3-O-glucoside: peonidin, delphinidin, petunidin, and malvidin; 3-p-coumaroyl-glucoside: cyanidin, peonidin, petunidin, and malvidin, and malvidin-3,5-diglucoside), five flavonoids (apigenin-7-glucoside, luteolin-7-glucoside, quercetin-3-galactoside, isorhamnetin-3-glucoside, and myricetin-3-rutinoside), and 26.62 mg GAE/g of phenolic compounds. In vivo assays, showed that Vitis labrusca extract at concentrations 100 and 300 mg/kg reduced carrageenan-induced mechanical and thermal hyperalgesia, 50 % of the paw edema, and neutrophil recruitment. In addition, there were no nephrotoxicity and hepatotoxicity. Our extract obtained from winemaking residue has analgesic and anti-inflammatory action, related at least in part to the presence of phenolic compounds, and it has no toxicity to renal and hepatic tissues. Novelty and scientific contribution. We demonstrated that this waste can be used for the production of antioxidant and anti-inflammatory products (pharmaceutical and cosmetics) without toxicity, contributing to the environmental economy.