Wine Lees Polyphenols as a Novel Functional Bioactive Compound in the Protection against Oxidative Stress and Hyperlipidemia

Abstract

Wine lees are the residual precipitate formed during wine fermentation, storage, fi ltration or centrifugation (1). The (poly)phenolic compounds in lees determine the colour, intensity and organoleptic properties of wine. Through biochemical processes in lees, enzymatic activitiy induces the transformation of phenols to high value--added polyphenolic compounds with in vivo physiological activity, such as gallic acid or ellagic acid, catechin, caff eic acid, resveratrol and others (2)(3)(4)(5) SummaryThe study examines the potential of wine industry by-product, the lees, as a rich mixture of natural polyphenols, and its physiological potential to reduce postprandial metabolic and oxidative stress caused by a cholesterol-rich diet in in vivo model. Chemical analysis of wine lees showed that their total solid content was 94.2 %. Wine lees contained total phenols, total nonfl avonoids and total fl avonoids expressed in mg of gallic acid equivalents per 100 g of dry mass: 2316.6±37.9, 1332.5±51.1 and 984.1±28.2, respectively. The content of total anthocyanins expressed in mg of cyanidin-3-glucoside equivalents per 100 g of dry mass was 383.1±21.6. Antioxidant capacity of wine lees determined by the DPPH and FRAP methods and expressed in mM of Trolox equivalents per 100 g was 259.8±1.8 and 45.7±1.05, respectively. The experiment lasted 60 days using C57BL/6 mice divided in four groups: group 1 was fed normal diet and used as control, group 2 was fed normal diet with added wine lees, group 3 was fed high-cholesterol diet (HCD), i.e. normal diet with the addition of sunfl ower oil, and group 4 was fed HCD with wine lees. HCD increased serum total cholesterol (TC) by 2.3-fold, triacylglycerol (TAG) by 1.5-fold, low-density lipoprotein (LDL) by 3.5-fold and liver malondialdehyde (MDA) by 50 %, and reduced liver superoxide dismutase (SOD) by 50 %, catalase (CAT) by 30 % and glutathione (GSH) by 17.5 % compared to control. Conversely, treatment with HCD and wine lees reduced TC and LDL up to 1.4 times more than with HCD only, with depletion of lipid peroxidation (MDA) and restoration of SOD and CAT activities in liver, approximating values of the control. HDL levels were unaff ected in any group. Serum transaminase activity showed no hepatotoxic properties in the treatment with lees alone. In the proposed model, wine lees as a rich polyphenol source could be a basis for functional food products without alcohol.

A Micromethod for Polyphenol High-Throughput Screening Saves 90 Percent Reagents and Sample Volume

“…In an animal experiment, wine lees were shown to be a rich source of polyphenols as a basis for functional food without alcohol. They were able to compensate for an unhealthy lifestyle in the case of a high-cholesterol diet, reducing oxidative stress levels and antioxidant enzymes to control values [31]. Results of these experiments are in agreement with a previous report [32] that emphasized the seeds of red grapes as being good sources for polyphenols.…”

Wine Lees as a Source of Antioxidant Compounds

“…Tao et al (2014) [19] indicated that the content of total phenolics extracted by ultrasound ranged between 44 and 59 mg GAE/g dry matter (DM), with the final yield at the optimal conditions being 58.77 mg GAE/g DM. However, in other studies lower values were found: 30.86 and 23.16 mg GAE/g DM [28,31]. In the study carried out by Romero-Díez et al (2018), wines lees were extracted using solvents with different polarities (water, methanol, ethanol, two hydroalcoholic mixtures and acetone), and total phenolic content ranged between 26 and 254 mg GAE/g DM, with the mixture of 75:25 ( v / v ) ethanol:water showing the highest efficiency [9].…”

Glutathionylation: a regulatory role of glutathione in physiological processes

“…) (65,97) and hydrogen peroxide (79,98), which intensify the pathological processes resulting in the activation of inflammatory cells in the adipose tissue, endothelial dysfunction, and atherogenesis in vascular tissues (72,99). Glutathionylation, therefore, plays a complex regulatory role in obesity, metabolic syndrome-related cardiovascular diseases, and diet-induced dyslipidaemia and cholesterolaemia (83,100).…”