Free Radical Scavenging Properties of Skin and Pulp Extracts of Different Grape Cultivars In Vitro and Attenuation of H2O2-Induced Oxidative Stress in Liver Tissue Ex Vivo

Abstract

Grapes are the richest source of antioxidants due to the presence of potent bioactive phytochemicals. In this study, the phytochemical contents, scavenging activities and protective role against H 2 O 2 -induced oxidative stress in liver tissue ex vivo of four grape (Vitis vinifera) cultivars extracts, namely Flame seedless (black), Kishmish chorni (black with reddish brown), Red globe (red) and Thompson seedless mutant (green), were evaluated. The total phenolics and flavonoids content in pulp or skin fractions of different grape cultivars were in the range of 47.6-310 mg gallic acid equivalent/g fresh weight (fw), and 46.6-733.3 lg catechin equivalent/g fw respectively. The scavenging activities in skin of different grape varieties against 2,2-diphenyl-1-picrylhydrazyl (44-58 %), hydrogen peroxide (15.3-18.6 %), and hydroxyl radicals (50-85 %), were higher than pulp of the corresponding cultivars. These scavenging activities of grape extracts were found to be significantly (p \ 0.01) correlated with the levels of total phenols, flavonoids and ascorbic acid. Liver tissues from goat treated with H 2 O 2 (500 lM) showed significantly decreased GSH content by 42.9 % and activities of catalase by 50 % and glutathione reductase by 66.6 %; while increased thiobarbituric acid reactive substances and nitric oxide level by 2.53-and 0.86-fold, respectively, and activity of glutathione S-transferase by 0.96-fold. Grape skin extracts showed the stronger protective activity against H 2 O 2 -induced oxidative stress in liver tissue ex vivo, than its pulp of any cultivar; and the Flame seedless (black) cultivar showed the highest potential. In conclusion, our study suggested that the higher antioxidant potential, phytochemical contents and significant scavenging capacities in pulp and skin of grape extracts showed the protective action of grape extracts against H 2 O 2 -induced oxidative stress in liver tissue ex vivo.

Characterization of the Omija (Schisandra chinensis) Extract and Its Effects on the Bovine Sperm Vitality and Oxidative Profile during In Vitro Storage

“…The antioxidant capacity of the tested extracts, reflected in the delay of LPO, confirmed the ability of the biomolecules of S. chinensis to prevent and/or delay oxidative damage, which was, furthermore, validated by a good correlation with DPPH and TEAC results. Moreover, Singha and Das [ 49 ] reported that the water extract of the Omija skin and pulp exhibited a potent peroxyl radical-scavenging capacity.…”

Dietary Phytochemicals Promote Health by Enhancing Antioxidant Defence in a Pig Model

“…In the present study, the plant extract doses were standardised for their respective total phenolic contents as GAE analysed by the Folin-Ciocateu assay. Whilst ascorbic acid is known to interfere with this assay [ 61 ], based on analyses conducted by others [ 61 , 62 , 63 , 64 , 65 , 66 , 67 ], the contributions of ascorbic acid to the GAE results are estimated to be 0.3% and 4% for grape skin and red cabbage extracts, respectively. These minimal contributions of ascorbic acid to the GAE results reflected the naturally low ascorbic acid content of grape skin [ 62 ], and the effects of microwave cooking [ 66 ] and ultrasonication [ 67 ] which reduced the ascorbic acid content of red cabbage during plant processing.…”

A Phenolic Acid and Flavonoid Fraction Isolated from Lolium multiflorum Lam. Prevents d-Galactosamine-Induced Liver Damages through the Augmentation of Nrf2 Expression

“…GSH, a nonenzymatic free radical scavenger, protects tissues from oxidative stress by directly interacting with ROS or as a cofactor for enzymatic detoxification [22,23]. SOD converts superoxide radicals to H 2 O 2 that is removed by the reaction with CAT and/or GSH [24].…”