Antioxidant Activity Of Phenolic Extracts Research Articles

Studying the Optimization, Characterization, and Antioxidant Activities of Phenolic Extracts Extracted from Rhus chinensis Mill. Leaf using Microwave-assisted Extraction System with Glycerol as a Green Solvent

Background: The leaves of Rhus chinensis Mill., a common deciduous tree found in the mild temperate zone of Asia, have many medicinal effects, including antioxidant properties. Objectives and Methods: This study aims to optimize the conditions for extracting phenols from Rhus chinensis Mill. (RCM) using a microwave-assisted extraction system with glycerol (MAEG) via response surface methodology (RSM). It also aims to compare the extraction efficacy of decoction and MAEG methods in terms of the bioactive compounds and antioxidant activities of the extracts obtained through them, identify bioactive compounds in both extracts via ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOFMS/ MS), and determine the cytotoxicity and cellular antioxidant activity of MAEG extract. Results: Temperature and glycerol concentration significantly affected the total phenolic content (TPC) of the extracts. The validated value of TPC was 84.11 ± 4.28 mg GAE/g for the sample obtained under the optimal conditions of 12.76 min at 54.08°C and 34.48% glycerol concentration. MAEG extract exhibited higher antioxidant properties compared to the decoction extract. Different phenolic compounds in the extracts were tentatively identified by LC-QTOF. MAEG concentrations from 1 mg/mL to 7.5 mg/mL were considered non-cytotoxic to NIH/3T3 fibroblasts. Furthermore, the cell viability of NIH/3T3 fibroblasts increased after being treated with MAEG extract (from 2.5 mg/mL to 7.5 mg/mL) and subjected to H2O2- induced oxidative stress compared to H2O2 treatment alone. Conclusion: Finally, MAEG can be used as a novel green extraction method for obtaining bioactive compounds for cosmetic and medicinal applications.

Synergistic effects of essential oils and phenolic extracts on antioxidant activities responses using two Artemisia species (A. campestris and A. herba alba) combined with Citrus aurantium

The aim of the present work was to investigate the synergistic effects of the binary and the ternary combinations of extracts using the following plants: A. campestris (AC), A. herba alba (AHA) and C. aurantium (CA). Antioxidant activities of essential oils (EO) were determined using DPPH and β-carotene assays, whereas, antioxidant activities of phenolic extracts (PE) were determined using DPPH, FRAP and ABTS assays. The antioxidants activities of the extracts combinations were evaluated using the Simplex Lattice Mixture Design. For the EOs, the results showed the existence of a very interesting dilution effect of CA for AC and AHA EOs (up to 1/3 vol fraction for DPPH and up to 1/2 for β-carotene). Alternatively, interesting synergistic effects were recorded in the following area of interest for the PEs “0.15 < AC<0.6 & AHA<1/3 & 1/3 < CA<2/3”. The synergistic effects was observed for the three tested antioxidant activities (DPPH, FRAP and ABTS).

Antimicrobial and antioxidant activity of phenolic extracts from walnut (Juglans regia L.) green husk by using pressure-driven membrane process.

The online version contains supplementary material available at 10.1007/s13197-022-05588-w.

Effect of processing on the antioxidant activities of porridges and Pittu prepared from finger millets (Eleusine coracana)

Finger millets are important coarse grains that exhibit high levels of phenolic compounds and antioxidant activities among other cereals. Grains are subjected to a number of thermal treatments and this could affect the contents and bioactivities of phenolic compounds. The aim of the present study was to determine the phenolic contents and antioxidant activities of finger millet flour and foods, namely porridges and Pittu subjected to several thermal treatments such as roasting, parboiling, and parboiled roasting of flour and open boiling and steaming of foods prepared using flour. The effect of the addition of spices on phenolic content and antioxidant activities to open boiled foods was determined. Antioxidant activities of phenolic extracts obtained from finger millet flour and foods were studied for their total phenolic, flavonoids and proanthocyanidins contents, radical scavenging capacities, reducing power, ferrous ion chelating capacity, and antioxidant activity in a β-carotene/linoleate emulsion. The roasted flour and foods had higher total phenolic content (TPC) than other counterparts and ranged from 21.58 to 28.63 µmol ferulic acid equivalents/g dry matter. All flour and food preparations exhibited effective inhibition of radicals, reducing power, ferrous ion chelating activity, and antioxidant activity in the β-carotene/linoleate emulsion and the degree of activity depended on the processing conditions adopted in food preparations.Foods prepared using steaming showed lower phenolic content and antioxidant activities in general than those of open-boiled counterparts. The addition of spices, namely garlic and cinnamon improved the phenolic contents and antioxidant activities of open-boiled porridges. The knowledge generated from this study may help to exploit the use of finger millets as a functional food ingredient to promote health and wellness.Graphical abstract

Cellular antioxidant activities of phenolic extracts from five sorghum grain genotypes

Measurement of antioxidant activity using biologically relevant methods is important for screening natural products for their potential health product development. The cellular antioxidant activities (CAA) based on Caco-2 cells and in vitro antioxidant activities (IAA; including ABTS, DPPH and FRAP assays) of free and bound phenolic extracts from both bran and kernel fractions of five coloured sorghum grain genotypes were examined. The CAA results were highly consistent with the IAA results, and both demonstrated a phenolic concentration dependent manner and were highly correlated with the contents of flavonoids (3-deoxyanthocyanidins and flavanones) and tannins (proanthocyanidins). The antioxidant activity of sorghum grain was mainly contributed by its readily extractable free form phenolics from the bran. Brown and black sorghums showed potent antioxidant activity, in which the brown-bran-free and black-bran-free phenolic extracts had the highest antioxidant activity. In addition, the black-bran-free phenolics had high cellular antioxidant quality, and the brown-bran-free phenolics had a high degree of the cell membrane and intracellular antioxidant effects. This study first investigated the CAA of sorghum phenolic extracts and the results demonstrated that brown and black sorghum bran has great potential to be developed as a natural antioxidant for food and nutraceutical applications.

Improving antioxidant effect of phenolic extract of Mentha piperita using nanoencapsulation process

In the present investigation, effect of chitosan, Alyssum homolocarpum gum (AHG) and complex (1:1) of chitosan and AHG (CCA) on the properties of nanoencapsulated Mentha piperita phenolic extract (polydispersity index (PDI), particle size, ζ-potential, encapsulation efficiency, release of phenolic compounds and evaluating effect of nanoencapsulation process on the antioxidant activity of phenolic extract of M. piperita in the soybean oil) was studied. The use of a high-pressure homogenizer, at pressure of 11,000 psi, reduced the particle size of W/O/W nanoemulsions coated with chitosan, CCA, and AHG, with a diameter of 108.66, 65.18, and 70.81 nm, respectively. Moreover, the PDI of nanoemulsions in AHG and CCA in all conditions was lower than 0.5, indicating the uniform size distribution and thus the success of the nanoparticle production process. The Intensity curve also showed that the emulsion generated by CCA had better emulsion droplets than the others due to its lower curve width and therefore greater uniformity. Also, the amount of ζ-potential of droplets of emulsions coated with chitosan, CCA and AHG were 28.69, 20.16 and − 37.4 mV, respectively. The results of the peroxide and p-anisidine test revealed that CCA extract caused the best oxidative stability in soybean oil, followed by AHG and chitosan, respectively, which were consistent with the results of the phenolic release test. Gradual and more release of phenolic compounds over time in the CCA-coated sample was superior to other samples.

Evaluation of the antioxidant activity of phenolic extracts from pomegranate bark (Punica granatum. L)

Pomegranates (Punica granatum) are among the fruits richest in vitamin C and phenolic compounds, in particular anthocyanins and phenolic acids. Sev-eral types of polyphenols with antioxidant properties are present in different parts of the pomegranate such as the stems and bark. This study aims to evaluate the antioxidant properties of extracts from the barks of P. gran-atum L for their use in the therapeutic and nutritional fields. The extraction of phenolic compounds was made using three solvents namely; methanol, ethanol and acetone. The total polyphenol dosing results revealed the meth-anolic extract’s richness in total phenolic composites with a ratio of about 2.940±0.087g EAG/g of lyophilization resultant extract. Likewise, the etha-nolic extract has shown a high concentration, followed by the acetonic extract, with total content of about 2.699 ± 0.057g EAG/g and 2.306 ± 0.026g EAG/g of lyophilization result extract, respectively. Antioxidant activity meas-ured by free root reduction (DDPH) revealed that the methanolic extract presented the most appropriate DPPH-root-inhibiting activity, with an inhib-iting concentration of 50% (IC50) being equal to 0.68 mg/ml. Moreover, the extracts obtained from the three solvents have shown efficiency compared to ascorbic acid (IC50 equal to 0.714±0.004mg/ml). Considering the antioxi-dant activities, it is recommended that P. granatum be used as a functional ingredient in the food industry and pharmaceutical preparations.

Nano-encapsulation of grape and apple pomace phenolic extract in chitosan and soy protein via nanoemulsification

Enhancement of lipid solubility and antioxidant activity besides maintenance of the stability for phenolics extract of grape and apple pomace could be achieved by their encapsulation. This work aims mainly to optimize nanocapsules (NCs) of total polyphenols extracted from golden apple (APP) and red grape (GPP) pomace in chitosan (polysaccharide) and soy protein. Nanoemulsification method was adopted with high encapsulation efficiency in case of soy protein, about 95%, and slightly lower efficiency for chitosan, about 75%. The NCs characteristics were confirmed by FTIR spectra, TEM, fluorescence spectra and spectrophotometric analysis. Good lipid NCs of oil/water emulsion type with diameter range of about 5˗300 nm were obtained in presence of Tween20 surfactant according to TEM images. FTIR spectra indicated that the most extracted polyphenolic compounds were encapsulated successfully. The NCs have enhanced the antioxidant activity of phenolic extract, apple juice and pineapple juice indicating their potential as food edible materials.

Antioxidant activity of phenolic extracts from olive mill wastewater and their influence on virgin olive oil stability

Fresh olive oil mill wastewaters (OMW) were collected in northern Morocco from industrial mills operating with three extraction systems (dual [C2] and triple phase [C3] centrifugation decanters and super-pressure system [SP]) during the 2017 growing season. Physicochemical and microbiological characteristics of these effluents were examined. OMW phenolic extracts were prepared and their antioxidant activities were evaluated. Moreover, the improvement of virgin olive oil stability by the addition of OMW phenolic extracts (at 100, 300 and 500 ppm) was investigated. Results from the present work confirmed the pollutant load of these effluents characterized by an acidic pH, strong organic content, and considerable amounts of mineral matter. Concerning the microbiological counts, yeasts and molds were the most abundant. Among extraction system, C2 displayed OMW with the high levels for all measured parameters, except for total phenols that were more abundant in C3. Findings from DPPH and FRAP tests showed a good antiradical potential and an important reducing power capacity and were both concentration-dependent. For the two tests, antioxidant activity of OMW phenolic extracts from C2 was the most important. The addition of phenolic extracts to virgin olive oil, stocked at 60°C, resulted in lower values of PV, K232 and K270 compared to the control, indicating a good protective effect against oil oxidation. The great antioxidant effect of OMW extracts was at 500 ppm, similar to that of ascorbic acid.

A systematic comparison of 25 Tunisian plant species based on oil and phenolic contents, fatty acid composition and antioxidant activity

This study investigated 25 Tunisian plant species of 13 families based on their oil and total phenolic contents. The fatty acid profiles and antioxidant activity of phenolic extracts of these plant seeds were studied in order to identify species containing unusual fatty acids and potential antioxidants. The oil content varied from 4.2 to 66.5% of DW (Dry Weight). Fatty acid profiles were determined using gas chromatography analysis coupled to flame ionization detection and high resolution mass spectrometry (GC-FID and GC-HRMS). The results showed that plant seeds were mostly composed of classic fatty acids (palmitic, oleic, linoleic and linolenic acids), while unusual fatty acids such as long-chain and odd-chain fatty acids were minor components. However, the petroselinic acid was the major component of Apiaceae family seed oil, particularly in Pimpinella saxifraga and Pimpinella major. The phenolic content of seed methanolic extracts, measured by Folin–Ciocalteu assay, varied between 30 and 4700 mg GAE/100 g DW. The methanolic extracts exhibited a broad range of antioxidant activity, varying from 13 to 17,000 mg TEAC/100 g DW in the DPPH assay. In the ABTS assay, the antioxidant activity values similarly varied from 4 to 18,100 mg TEAC/100 g DW. The seeds of Apium graveolens, Anethum graveolens, Pimpinella saxifraga and Lepidium sativum had high oil content, interesting fatty acid profiles and their methanolic extracts displayed high antioxidant capacities. This investigation of Tunisian plants showed the potentialities of several species that could be scale-up cultivated for commercial purposes.

Chromatographic fingerprint analysis, antioxidant properties, and inhibition of cholinergic enzymes (acetylcholinesterase and butyrylcholinesterase) of phenolic extracts from Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill bark.

Irvingia gabonensis stem bark is a medicinal plant used in most parts of Africa to manage a number of ailments including neurodegenerative diseases that occur without scientific basis. This work characterized the phenolic composition, evaluated the cholinergic enzymes (acetylcholinesterase, AChE and butyrylcholinesterase, BChE) inhibition, and assessed the antioxidant activity of phenolic extracts from I. gabonensis (Aubry-Lecomte ex O'Rorke) Baill bark. Total phenol and flavonoids content was evaluated in addition to antioxidant activity as shown by Fe2+ chelation, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, and 2,2-azino-bis-(3-ethylbenthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability. Inhibitory activities on AChE and BChE were evaluated. The extract was found to be rich in phenolic acid (ellagic acid) and flavonoids (quercetrin, kaempferol, and apigenin). The phenolic extracts displayed DPPH radical scavenging ability (IC50=19.98 μg/mL), ABTS radical scavenging ability (IC50=18.25 μg/mL), iron chelation (IC50=113.10 μg/mL), and reducing power (Fe3+ to Fe2+) (5.94 mg ascorbic acid equivalent/100 g). Extracts of I. gabonensis inhibited AChE (IC50=32.90 μg/mL) and BChE (IC50=41.50 μg/mL) activities in concentration-dependent manner. Hence, possible mechanism through which the stem bark executes their anti-Alzheimer's disease activity might be by inhibiting cholinesterase activities in addition to suppressing oxidative-stress-induced neurodegeneration.

Comparison Between Antioxidant Activities of Phenolic Extracts from Mexican Peanuts, Peanuts Skins, Nuts and Pistachios

Recently, several works have been done in order to study antioxidant compounds like resveratrol present in oilseeds since they are able to protect from cells damage related to heart disease and cancer. In the present research a chemical analysis and the identification of bioactive compounds of peanuts, nuts and pistachios varieties were carried out. The walnut variety showed the highest content of total phenolic compounds (1404 ± 23 mg GAE/100 g) and antioxidant capacity (191 ± 4.2 μmol TE/g). Phenolic compounds resveratrol, catechin, epicatechin and quercetin were identified in all samples.

The negligible role of ellagic acid in preventing fat oxidation of Tunisian walnuts (Juglans regia L.)

Antioxidant activity of phenolic extract isolated from Tunisian walnut (Juglans regia L.) fruits has been investigated. Preliminarily, composition of walnut kernels was determined. Fat content varied from 53.5 to 66.9% (w/w), while total phenol ranged from 1.2 to 5.2 g/100 g of kernel as gallic acid equivalent (GAE). High amounts of ellagic acid (EA) and its derivatives were evidenced by HPLC analysis of the phenolic extract. Walnut fat showed induction time ranging from 2.5 to 3.7 h at 110 °C (rancimat test) and these values unchanged by adding 300 mg/kg of kernel phenolic extract which so showed to have no antioxidant effect. In addition, activities of the ellagic and gallic acids and trolox were compared in vitro by using the Folin–Ciocalteu’s, rancimat and DPPH radical scavenging methods. EA exhibited an antioxidant and radical scavenging activity significantly lower than other tested substances. In conclusion, EA showed to have a negligible role in preventing walnut fat oxidation.

Антиоксидантная активность фенольных экстрактов травы дубровника белого

Антиоксидантная активность фенольных экстрактов травы дубровника белого

Phenolic Profiles and Antioxidant Activity of Lotus Root Varieties.

Lotus root attracts increasing attention mainly because of its phenolic compounds known as natural antioxidants. Its thirteen varieties were systematically analyzed on the content, distribution, composition and antioxidant activity of phenolic compounds for a better understanding of this aquatic vegetable. The respective mean contents of total phenolics in their flesh, peel and nodes were 1.81, 4.30 and 7.35 mg gallic acid equivalents (GAE)/g fresh weight (FW), and those of total flavonoids were 3.35, 7.69 and 15.58 mg rutin equivalents/g FW. The phenolic composition determined by a high-performance liquid chromatography method varied significantly among varieties and parts. The phenolics of flesh were mainly composed of gallocatechin and catechin; those of peel and node were mainly composed of gallocatechin, gallic acid, catechin and epicatechin. The antioxidant activities of phenolic extracts in increasing order were flesh, peel and node; their mean concentrations for 50% inhibition of 2,2-diphenyl-1-picrylhydrazyl radical were 46.00, 26.43 and 21.72 µg GAE/mL, and their mean values representing ferric reducing antioxidant power were 75.91, 87.66 and 100.43 µg Trolox equivalents/100 µg GAE, respectively. “Zoumayang”, “Baheou”, “No. 5 elian” and “Guixi Fuou” were the hierarchically clustered varieties with relatively higher phenolic content and stronger antioxidant activity as compared with the others. Especially, their nodes and peels are promising sources of antioxidants for human nutrition.

Integrated membrane process for purification and concentration of aqueous Syzygium cumini (L.) seed extract

The aim of the present study was to investigate the potentiality of an integrated membrane process for the purification and the concentration of phenolic compounds from aqueous jamun (Syzygium cumini L.) seed extract. The aqueous seed extract obtained at optimal condition (temperature: 49.2°C, time: 89.4min, and liquid to solid ratio: 51.6:1mL/g) was submitted to cross flow ultrafiltration for initial clarification, followed by concentration using nanofiltration under batch concentration mode. A detailed parametric study was carried out to investigate the effect of various process parameters such as transmembrane pressure, cross-flow velocity (or stirrer speed) on the permeate flux and permeate quality. Using classical film theory, a steady state gel polarization model incorporating the effect of transmembrane pressure difference and viscosity variation was proposed for the prediction of permeate flux during cross flow ultrafiltration of aqueous seed extract. The predicted flux values were successfully compared with the experimental results. Experimental results showed that the operating conditions had significant effect on permeate flux, recovery of polyphenols, purity and antioxidant activity of phenolic extract. Ultrafiltration experiments at lower operating pressures (276 and 414kPa) using 100kDa membrane resulted in the recovery of 59–66.7% of total polyphenol content in the clarified extract with the purity of 49–58.3% starting from an extract purity of 39.2%. The clarified extract could be successfully concentrated about three times higher using 250Da nanofiltration membrane at volume concentration ratio of three. The present study revealed that the UF/NF integrated membranes process was successful in clarifying and concentrating phenolic extract obtained from jamun seed with enhanced purity and antioxidant activity.

Antioxidant activity of phenolic extracts from different cultivars of Italian onion (Allium cepa) and relative human immune cell proliferative induction

Context: The total antioxidant activity (TAC) may vary considerably between onion cultivars. Immunological effects of onion phenolic compounds are still underestimated.Objective: The objective of this study is to determine the total phenol content (TPC) and the relative TAC of three Allium cepa L. (Liliaceae) onion cultivars cultivated in Cannara (Italy): Rossa di Toscana, Borettana di Rovato, and Dorata di Parma, and to evaluate the phenol extracts ability to induce human immune cell proliferation.Materials and methods: TPC was determined by the Folin–Ciocalteu method, TAC with FRAP, TEAC/ABTS, and DPPH methods. Peripheral blood mononuclear cells from healthy human donors were incubated for 24 h at 37 °C with 1 ng/mL of phenolic extract in PBS, immunostained, and then analyzed by 4-color flow cytometry for the phenotypic characterization of T helper cells (CD4+ cells), cytotoxic T lymphocytes (CD8+ cells), T regulatory cells (CD25high CD4+ cells), and natural killer cells/monocytes (CD16+ cells).Results: Rossa di Toscana displayed the highest TPC (6.61 ± 0.87 mg GA equivalents/g onion bulb DW) and the highest TAC with the experienced methods: FRAP, 9.19 ± 2.54 μmol Trolox equivalents/g onion bulb DW; TEAC/ABTS, 21.31 ± 0.41 μmol Trolox equivalents/g onion bulb DW; DPPH, 22.90 ± 0.01 μmol Trolox equivalents/g onion bulb DW. Incubation with Rossa di Toscana extract determined an increase in the frequency of the antitumor/anti-infection NK CD16+ immune cells (23.0 ± 0.4%).Discussion and conclusions: Content of health-promoting phenols and the deriving antioxidant and immunostimulating activity vary considerably among the investigated cultivars. Rossa di Toscana can be considered as a potential functional food.

Antioxidant activity of phenolic extracts from chestnut fruit and forest industries residues

In this work, extracts from various lignocellulosic wastes were analyzed with the aim of applying them to prevent colour ultraviolet degradation of dyed veneers used for board coating. Chestnut fruit (Castanea sativa) shell and bur, barks from Pinus pinaster, Eucalyptus globulus, Quercus frainetto and Quercus robur and wood from Tilia cordata were extracted using water or aqueous solutions of sodium sulphite and/or sodium hydroxide. The extracts were analyzed for their antioxidant activity (using the ferric reducing antioxidant power, the free radical DPPH and the free radical ABTS essays), totals phenols content, molecular weight distribution and phenolic composition. Except for chestnut bur and steam peeled chestnut shell whose water extract was the best, the best antioxidant properties were obtained for the 2 % sodium sulphite extracts. Extracts from pine bark and steam peeled chestnut shell, with the highest total phenols content and antioxidant activity, not only showed the best properties as bioprotectors but also high extraction yields. These extracts also presented the higher average molecular weights. Extract antioxidant properties were related to the presence of various phenolic compounds identified by reverse phase high-performance liquid chromatography electrospray ionization time-of-flight mass spectrometry: flavan-3-ols, flavonols, flavonol glycosides, dihydroflavonols and phenolic acids.

Profile and Antioxidant Activity of Phenolic Extracts from 10 Crabapples (Malus Wild Species)

Phenolic products are highly demanded by the food and cosmetics industries and consumers due to their high antioxidant activities. To evaluate the potential of crabapples (Malus wild species) in preparing phenolic extracts, fruits of 10 crabapples grown in China were separately extracted with 80% (v/v) ethanol and ethyl acetate and the phenolic profiles, polyphenol (PC) and flavonoid contents (FC), and antioxidant activities of the extracts were analyzed. Chlorogenic acid, (-)-epicatechin, rutin, hyperin, and phlorizin appeared as the major phenolic compounds in all phenolic extracts. Ethanol extracts had PC of 302.83-1265.94 mg GAE/100g and FC of 352.45-2351.74 mg RE/100g, being 4.17 and 4.49 times those obtained in ethyl acetate extracts and much higher than those previously reported in apples. Malus wild species appeared as rich sources of phenolic compounds with high antioxidant activity, especially when high chlorogenic acid and rutin contents are emphasized.

Antioxidant activity profiling by spectrophotometric methods of phenolic extract of Prasium majus L

IntroductionPhytochemicals are extensively found at different levels in many medicinal plants. To investigate the phenolic compound content and in vitro antioxidant activity of phenolic extract from Prasium majus L (Lamiaceae). MethodsThe present investigation comprises, estimation of total polyphenol, flavonoid, tannin, in vitro antioxidant assays such as total antioxidant capacity, DPPH, ABTS, β-carotene and ferric reducing power. ResultsP. majus exhibited 64.25 mg GAE g−1 extract of polyphenol phenol content, and better scavenging activity of DPPH (IC50 = 7.95 μg mL−1), ABTS+ (IC50 = 373.78 μg mL−1), and β-carotene (IC50 = 122.56 μg mL−1). ConclusionOur results clearly demonstrated that phenolic extract P. majus has antioxidant capacity. Therefore is a valuable source of natural antioxidants.