In Vitro Bioaccessibility of Extractable Compounds from Tannat Grape Skin Possessing Health Promoting Properties with Potential to Reduce the Risk of Diabetes

Abstract

Diabetes pathogenesis encompasses oxidative stress, inflammation, insulin malfunctioning and partial or total insulin secretion impairment, which leads to a constant hyperglycemia. Polyphenols are known to possess bioactive properties, being Tannat grape skin a natural and sustainable source of these compounds. The present study aimed to find out the bioaccessibility of health-promoting molecules composing a multifunctional extract from Tannat grape skin obtained under hydro-alcoholic-acid conditions. The identification of phenolic compounds in the samples was performed by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Subsequently, the samples were in vitro digested mimicking the human oral gastrointestinal conditions and the bioactivity of the digest (antioxidant, anti-inflammatory and modulation of glucose metabolism) was assessed. Effect on glucose metabolism was estimated by measuring carbohydrases activity and the functionality of glucose transporters of small intestine cells in presence and absence of the digested extract. Flavonoids, phenolic acids and phenolic alcohols were the major phenol compounds detected in the extract. The bioaccessible compounds protected the intestinal cells and macrophages against the induced formation of reactive oxygen species (ROS) and nitric oxide (NO). In addition, glucose transporters were inhibited by the digested extract. In conclusion, the bioaccessible compounds of the extract, including phenols, modulated key biochemical events involved in the pathogenesis of diabetes such as oxidative stress, inflammation and glucose absorption. The extract was effective under prevention with co-administration conditions supporting its potential for either reducing the risk or treating this disease.

In Vitro Bioaccessibility of Bioactive Compounds from Citrus Pomaces and Orange Pomace Biscuits

“…Hesperidin, narirutin, naringenin-7-O-glucoside, and rutin have been found to remain in the bioaccessible fractions of Clementine mandarin and Navel orange pulps [16], which are present in the raw citrus pomaces of the current work. Antioxidant compounds' loss by means of the digestion process has already been reported for oregano samples [7], persimmon fruit byproduct flours [17], wild blueberries [18], and red grape skin [19]. Specifically, a study conducted on citrus peel extracts showed that flavonoids and antioxidant activity were sensitive to pH conditions during in vitro gastrointestinal digestion [20].…”

“…Solutions of 10 mg/mL in H2O:MeOH (50:50, v/v) of Clemenule and Ortanique mandarin and Navel and Valencia orange pomaces were analyzed by UHPLC-MS/MS. The analysis of phenolic compounds was carried out according to the method described by Fernández-Fernández et al [19]. Briefly, the identification and quantification of these compounds was performed using a Thermo Ultimate™ 3000 HPLC (Thermo Scientific, Sunnyvale, CA, USA) coupled to a hybrid quadrupole-orbitrap mass spectrometer (Q-ExactiveTM; Thermo Scientific, Bremen, Germany), equipped with heated electrospray ionization (HESI-II).…”

“…Briefly, the identification and quantification of these compounds was performed using a Thermo Ultimate™ 3000 HPLC (Thermo Scientific, Sunnyvale, CA, USA) coupled to a hybrid quadrupole-orbitrap mass spectrometer (Q-ExactiveTM; Thermo Scientific, Bremen, Germany), equipped with heated electrospray ionization (HESI-II). Chromatographic separation was carried out using a UPLC BEH C18 Fernández-Fernández et al [19]. Briefly, the identification and quantification of these compounds was performed using a Thermo Ultimate™ 3000 HPLC (Thermo Scientific, Sunnyvale, CA, USA) coupled to a hybrid quadrupole-orbitrap mass spectrometer (Q-ExactiveTM; Thermo Scientific, Bremen, Germany), equipped with heated electrospray ionization (HESI-II).…”

Antioxidant, Antidiabetic, and Antiobesity Properties, TC7-Cell Cytotoxicity and Uptake of Achyrocline satureioides (Marcela) Conventional and High Pressure-Assisted Extracts

“…α-amylase inhibition assay was evaluated as another antidiabetic strategy and performed as reported by Li, Yao, Du, Deng, and Li [ 18 ] with some modifications described by Fernández-Fernández et al [ 19 ]. The inhibition capacity was calculated by taking positive control as 100% of enzyme activity.…”

Grapes and Their Derivatives in Functional Foods

“…Furthermore, grape skin extract with a high content of phenolic compounds (flavonoids, phenolic acids, and phenolic alcohols) may have the potential to reduce the risk of diabetes. Indeed, the bioaccessible compounds of grape skin extract proved capable of modulating the key biochemical events involved in the pathogenesis of diabetes, such as oxidative stress, inflammation, and glucose absorption [ 10 ].…”