Chemical Composition, Antioxidant, Antimicrobial and Cytotoxic/Cytoprotective Activity of Non-Polar Extracts of Grape (Vitis labrusca cv. Bordeaux) and Blackberry (Rubus fruticosus) Seeds

Abstract

The aim of this study was to compare the influence of the extraction method, chemical composition, antimicrobial effects, antioxidant activity, and cytotoxicity on human cells of the non-polar extracts of grape (Vitis labrusca) and blackberry (Rubus fruticosus) seeds. The Soxhlet (Sox), Bligh–Dyer (BD), and ultrasound (US) methods were used for extractions. For blackberry non-polar seed extract, extraction via the BD method showed the highest mean values of total phenolic content (TPC), expressed in milligrams of gallic acid equivalent per 100 mL of non-polar seed extracts (102.37 mg GAE/100 mL), and higher antioxidant activity in relation to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, expressed in milligrams of gallic acid equivalent per 100 mL of non-polar seed extracts (11.50 mg AAE/100 mL), if compared with the Sox and US extractions. Similar results were obtained for the non-polar grape seed extracts, where BD extraction obtained the highest values for TPC (28.61 mg GAE/100 mL) and DPPH (35.36 mg AAE/100 mL). The type of extraction method had an impact on the composition of fatty acids. Only the non-polar blackberry and grape seed extracts obtained via the Sox method showed some in vitro inhibitory effect against Escherichia coli (IAL 2064) and Staphylococcus aureus (ATCC 13565). Regardless of the extraction method used, the non-polar blackberry and grape seed extracts did not decrease the cell viability (IC50 >1000 µg/mL) of cancer and normal cell lines, thus indicating the relative safety of the extracts. All the seed extracts decreased the generation of reactive oxygen species in the cell lines. Blackberry and grape seed lipid fractions can be utilized as antioxidants, and the extraction methods used cause significant changes in relation to their bioactivity and chemical composition.

The use of ultrasound in the South Cone region. Advances in organic and inorganic synthesis and in analytical methods

“…Table 1 shows 29 works from Chile [140] , [141] , [142] , [143] , [144] , [145] , [146] , Uruguay [147] , [148] , Southern Brazil [149] , [150] , [151] , [152] , [153] , [154] , [155] , [156] , [157] , [158] , [159] and Argentina [160] , [161] , [162] , [163] , [164] , [165] , [166] , [167] , [168] , [169] reported during the last 10 years The most important aspects highlighted were that ultrasound helped and improved extraction procedures, reduced operational time, enhanced extraction yields and made it greener in comparison to traditional extraction methods, according to others publication [170] . Nevertheless, the use of ultrasound did not always improve the performance of an analytical procedure or showed an important benefit in an extraction process [140] , [160] , [171] , [172] , [173] .…”

“… Improved the extraction of bioactive compounds [166] Phenolic compounds brewer’s spent grain UAE ES: ethanol:water Liquid/solid ratio of 30:1 mL/g, (UP) (50% of amplitude, 20 KHz of frequency and 45 W) for 60 min ------- [167] Phenolic compounds Remaining solid (waste) after processing blackcurrant juice UAE ES: citric acid sample:solvent ratio (1:3), sonicated (UP) 60% amplitude,10 min extraction time (7.45 min), solvent concentration (1.70 M), and ultrasonic amplitude (100%) Fast mass transfer of the analytes from the sample solution improved the efficiency of extraction, diminished extraction time, and solvent consumption [168] Gallic acid, resveratrol, catechin and malvidin Brazilian wines UALLE ES: acidified (with 37 % hydrochloric acid) ethyl acetate 200 μL of wine, 4 mg of sodium chloride, 4 mg of sodium metabisulfite, 600 μL 37 % hydrochloric acid, sonicates(USB) 200 W for 7 min ------- [169] Antioxidant Grape and blackberry UAE ES: hexane 5.0 g sample and 100 mL of hexane, USB (130 W, 20 kHz) in pulse mode (25 ◦ C) 40 min. US was not the best extraction method [171] Antioxidant Cajazeira leaves UAE ES:hexane, ethyl acetate, ethanol, water and a mixture of ethanol and water in a ratio of 1: 1 (v/v) 5.0 g of dried and ground leaves, 150 mL of ES and UP (20 kHz, 500 W, 4 mm titanium microtip). Extractions were performed at room temperature for 8 min with 50% sonication amplitude (250 W).…”

Selected Seeds as Sources of Bioactive Compounds with Diverse Biological Activities

“…Aside from polyphenols, numerous other types of phytochemicals have been isolated from seeds. They include, but are not limited to phenyl alcohols, phenolic glycosides, phytosterols, terpenoids, terpenophenols, tocochromanols, lignanamides, tannins, nitrogen-containing compounds, and saponins [ 4 , 23 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ]. Terpenoids can be divided into several groups, including triterpenoids and tetraterpenoids.…”

“…Blackberries ( Rubus fruticosus L.) are shrubs belonging to the Rosaceae family, and are widely distributed in the northern hemisphere [ 79 , 80 , 81 ]. Blackberry seeds contain phenolic acids (ellagic acid, gallic acid, gallic hexoside), flavonoids (quercetin and its derivatives), anthocyanins (peonidin-3-glucoside), procyanidins (procyanidin B 1 ), ellagitannins (sanguiin H-6), phytosterols (β-sitosterol), carotenoids, and tocopherols [ 6 , 11 , 29 , 79 , 82 ]. Ayoub et al reported that blackberry seed meal had a higher concentration of total phenolics than some of the other similar plant species, like black raspberry and blueberry, which correlated with stronger antioxidant activity [ 6 ].…”

“…The antioxidant activity of various blackberry seed extracts was documented in multiple in vitro studies [ 6 , 11 , 29 , 79 ]. Wajs-Bonikowska et al compared the radical-scavenging activity of several seed extracts depending on the type of eluent used in the extraction process.…”