Antioxidants in Natural Products

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Chemical and Molecular Sciences".

Deadline for manuscript submissions: closed (31 July 2020) | Viewed by 53209
Related Special Issue: Antioxidants in Natural Products II

Special Issue Editors


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Guest Editor
Laboratory of Analytical Chemistry, Department of Chemistry, School of Sciences, National and Kapodistrian University of Athens, 15771 Athens, Greece
Interests: analytical chemistry; method validation; antioxidants; natural products
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Department of Chemistry, Faculty of Engineering, Istanbul University-Cerrahpasa, Istanbul, Turkey
Interests: analytical method development for antioxidants and other food constituents; optical sensors; nanosensors; energetic materials; biologically and environmentally important compounds

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Guest Editor
Department of Chemistry, Faculty of Science, Istanbul University, 34126 Istanbul, Turkey
Interests: analytical method development for antioxidants and other food constituents; optical sensors; nanosensors; food chemistry; natural products chemistry; phytochemicals; antioxidants
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The importance of consuming antioxidants in food, beverages, and so on, has increased enormously during the last decade. Natural antioxidants, such as polyphenols, carotenoids, and vitamin C, exhibit a plethora of biological effects, including anti-inflammatory, anti-aging, anti-atherosclerosis, and anticancer. Extended original scientific research has been devoted to the evaluation of the antioxidant activity of natural products, such as olive oil, fruits, vegetables, as well as to the extraction, isolation, and characterization of antioxidant compounds from medicinal plants, spices, and marine sources. Extensive research has also been devoted to the recovery of antioxidants from olive mill waste, winery waste, and other wastes.

The scope of the Special Issue, entitled “Antioxidants in Natural Products”, is to collect all of the available scientific research on the discovery of new antioxidants from all kinds of natural products, as well as their uses for human benefit, and to critically present the available and emerging analytical methods for the measurement of the antioxidant activity and other quality parameters of natural products.

Prof. Dr. Reşat Apak
Prof. Dr. Antony C. Calokerinos
Prof. Dr. Mustafa Bener
Guest Editors

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Keywords

  • antioxidants
  • natural products
  • medicinal plants
  • spices
  • marine sources
  • olive mill waste
  • winery waste
  • antioxidant activity
  • quality parameters
  • analytical methods for antioxidants

Published Papers (16 papers)

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Editorial

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3 pages, 184 KiB  
Editorial
Special Issue on Antioxidants in Natural Products
by Antony C. Calokerinos, Reşat Apak and Mustafa Bener
Appl. Sci. 2022, 12(17), 8715; https://doi.org/10.3390/app12178715 - 30 Aug 2022
Cited by 1 | Viewed by 877
Abstract
The importance of consuming antioxidants in food and beverages has increased enormously in recent years [...] Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)

Research

Jump to: Editorial, Review

13 pages, 1232 KiB  
Article
The Effect of Light on Antioxidant Properties and Metabolic Profile of Chia Microgreens
by Selma Mlinarić, Vlatka Gvozdić, Ana Vuković, Martina Varga, Ivan Vlašiček, Vera Cesar and Lidija Begović
Appl. Sci. 2020, 10(17), 5731; https://doi.org/10.3390/app10175731 - 19 Aug 2020
Cited by 20 | Viewed by 3794
Abstract
Chia (Salvia hispanica L.) is a one-year plant known as a source of nutrients that can be consumed in the diet in the form of seeds or sprouts. The purpose of this study is to investigate the effect of illumination for 24 [...] Read more.
Chia (Salvia hispanica L.) is a one-year plant known as a source of nutrients that can be consumed in the diet in the form of seeds or sprouts. The purpose of this study is to investigate the effect of illumination for 24 and 48 h on dark-grown chia microgreens. Total antioxidant capacity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assays, along with the total phenolics, ascorbic acid and cellulose content, and chlorophyll and carotenoid concentrations. Fourier transform infrared spectroscopy (FTIR) was used to evaluate the biochemical composition and elucidate the changes in compound structures between dark-grown and illuminated chia microgreens. Analysis of the results showed that illumination significantly increased the content of all measured bioactive compounds as well as antioxidative capacity, especially 48 h after exposure to light. FTIR analyses supported structural and molecular changes in chia microgreens grown under different light regimes. Our results suggest that illumination has a positive effect on the antioxidant potential of chia microgreens, which may present a valuable addition to the human diet. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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22 pages, 523 KiB  
Article
Antioxidant and Antiglycation Properties of Seventeen Fruit Teas Obtained from One Manufacturer
by Izabela Zieniewska, Anna Zalewska, Małgorzata Żendzian-Piotrowska, Jerzy Robert Ładny and Mateusz Maciejczyk
Appl. Sci. 2020, 10(15), 5195; https://doi.org/10.3390/app10155195 - 28 Jul 2020
Cited by 6 | Viewed by 3102
Abstract
The antioxidant activity of teas depends on the type and quality of the ingredients used in the process of tea production, location of the crops, and manner of the raw material processing. Our study is the first to compare the antioxidant and antiglycation [...] Read more.
The antioxidant activity of teas depends on the type and quality of the ingredients used in the process of tea production, location of the crops, and manner of the raw material processing. Our study is the first to compare the antioxidant and antiglycation properties of seventeen fruit teas obtained from one manufacturer. We evaluated three different brewing times (3, 5, and 10 min) and two brewing temperatures (70 and 100 °C). We demonstrated that infusions with the longest brewing time reveal the highest antiradical activity, while increased brewing temperature does not significantly affect the assessed parameters. The best antioxidant properties were obtained for the teas made from lemon balm with pear, forest fruits, cranberry with pomegranate, raspberry, and raspberry with linden. Fruit teas owe their high antioxidant activity to the presence of polyphenolic compounds in infusions. Extracts from fruit teas also diminish the oxidation and glycation of albumin in vitro, observed as a decrease in the fluorescence of aromatic amino acids and advanced glycation (AGE) and oxidation (AOPP) protein products levels. In conclusion, in order to prepare fruit teas with the best antioxidant properties, a longer extraction time is needed. The health-promoting properties of dried fruit infusions can be modified by changing the qualitative and quantitative composition of the ingredients. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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16 pages, 2838 KiB  
Article
Ginkgo biloba Alleviates Cisplatin-Mediated Neurotoxicity in Rats via Modulating APP/Aβ/P2X7R/P2Y12R and XIAP/BDNF-Dependent Caspase-3 Apoptotic Pathway
by Dina H. Gomaa, Walaa G. Hozayen, Haidy Al-shafeey, Asmaa Mohammed M. Hussein Elkelawy and Khalid S. Hashem
Appl. Sci. 2020, 10(14), 4786; https://doi.org/10.3390/app10144786 - 12 Jul 2020
Cited by 11 | Viewed by 2244
Abstract
Neurotoxicity is an obvious adverse effect in Patients encountering a complete course of chemotherapy. The present work is conducted to evaluate the neuroprotective effect of Ginkgo biloba (Ginkgo) against the neurotoxicity induced by Cisplatin (Cis) in rats. Forty male Wistar albino [...] Read more.
Neurotoxicity is an obvious adverse effect in Patients encountering a complete course of chemotherapy. The present work is conducted to evaluate the neuroprotective effect of Ginkgo biloba (Ginkgo) against the neurotoxicity induced by Cisplatin (Cis) in rats. Forty male Wistar albino rats were arranged into four groups: (1) Control group, rats were given saline; (2) Cis group, rats were injected by Cis 2 mg/kg body weight i.p., twice a week starting on the fifth day for thirty days; (3) Ginkgo group, rats were administered Ginkgo (50 mg/kg orally) daily for thirty days; and (4) Ginkgo+Cis group, rats received Ginkgo (50 mg/kg orally) daily and on the fifth day, rats were injected with Cis (2 mg/Kg body weight i.p.) twice a week for thirty days. Cis significantly increased Gamma glutamyltransferase (GGT) and Acetyl Cholinesterase (CHE) as compared to the control group and also disturbed cerebral oxidative/antioxidant redox. Co-administration of Ginkgo and Cis reversed the adverse effect of Cis on the brain tissue. Moreover, co-administration of Ginkgo and Cis ameliorated Cis induced brain damage by reducing Amyloid precursor protein (APP), amyloid β (Aβ), P2Y12R and P2X7R mRNA expressions and proteins. Furthermore, Ginkgo regulated XIAP/BDNF expressions with a consequent decrease of caspase-3 and DNA fragmentation%. The current results concluded that concurrent treatment with Ginkgo can mitigate neurotoxicity mediated by Cis in experimental animals through exhibiting antioxidant effect by restoring cerebral oxidative/antioxidant redox and anti-apoptotic effect via regulating cerebral APP/Aβ/P2Y12R/P2X7R and XIAP/BDNF signaling pathways. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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15 pages, 1958 KiB  
Article
Characterization of Bioactive Ligands with Antioxidant Properties of Kiwifruit and Persimmon Cultivars Using In Vitro and in Silico Studies
by Young Mo Kim, Yong Seo Park, Yang-Kyun Park, Kyung-Sik Ham, Seong-Gook Kang, Raja Mohamed Beema Shafreen, Selvaraj Alagu Lakshmi and Shela Gorinstein
Appl. Sci. 2020, 10(12), 4218; https://doi.org/10.3390/app10124218 - 19 Jun 2020
Cited by 10 | Viewed by 2872
Abstract
The current study attempted to understand the interaction profiles of phytoconstituents in new and traditionally used fruit cultivars with human serum albumin (HSA) in the context of predicting the biological role under in vivo conditions. Therefore, polyphenols, flavonoids, flavanols, tannins, vitamin C, secondary [...] Read more.
The current study attempted to understand the interaction profiles of phytoconstituents in new and traditionally used fruit cultivars with human serum albumin (HSA) in the context of predicting the biological role under in vivo conditions. Therefore, polyphenols, flavonoids, flavanols, tannins, vitamin C, secondary metabolites and their antioxidant capacities of organic kiwifruit Actinidia (A.) eriantha cv. Bidan (AEB) and A. arguta cv. Cheongsan (AAC), as new cultivars grown in Korea, and widely consumed A. deliciosa cv. Hayward (ADH) and Diospyros kaki Thunb. cv. Fuyu (DKF) were determined and compared. All investigated fruits showed relatively high antioxidant capacities. To complement the bioactivity of these fruits, the binding properties between extracted polyphenols and HSA were determined by 3D-fluorescence spectroscopy and docking studies. The most bioactive was AEB with the highest percentage of binding, following by AAC, ADH and DKF. Our study for the first time unveils the differential binding properties of kiwifruit and persimmon phytoconstituents with HSA. Although cultivars possess virtually the same phytoconstituents, presence of one unique compound significantly alters the binding properties of HSA. The results of fluorescence quenching and molecular docking showed that these fruits possess multiple properties, which have a great potential to be used in industry with emphasis on the formulation of functional foods and medicinal applications. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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16 pages, 3333 KiB  
Article
High-Performance Green Extraction of Polyphenolic Antioxidants from Salvia fruticosa Using Cyclodextrins: Optimization, Kinetics, and Composition
by Spyros Grigorakis, Amina Benchennouf, Abedalghani Halahlah and Dimitris P. Makris
Appl. Sci. 2020, 10(10), 3447; https://doi.org/10.3390/app10103447 - 16 May 2020
Cited by 13 | Viewed by 2331
Abstract
S. fruticosa, collectively known as Cretan sage, is a medicinal plant to which a number of bioactivities have been attributed. In spite of its importance in nutrition and pharmacy, reports on the extraction of major polyphenols using sustainable processes are particularly limited. [...] Read more.
S. fruticosa, collectively known as Cretan sage, is a medicinal plant to which a number of bioactivities have been attributed. In spite of its importance in nutrition and pharmacy, reports on the extraction of major polyphenols using sustainable processes are particularly limited. In this study, three common cyclodextrins, namely, methyl β-cyclodextrin (m-β-CD), hydroxypropyl β-cyclodextrin (HP-β-CD), and β-cyclodextrin (β-CD), were tested as green boosters of aqueous extraction of polyphenols from aerial parts of S. fruticosa. To examine simultaneously important extraction parameters, including the concentration of cyclodextrins (CCD), pH, and liquid-to-solid ratio (RL/S), a Box–Behnken design was chosen, with three central points. Temperature effects on the extraction yield were also considered, by carrying out kinetics. The results showed that m-β-CD was the most effective extraction booster, providing total polyphenols yields that amounted to 98.39 mg gallic acid equivalents g−1 dry mass. The kinetic assay demonstrated that extraction was highly effective at 80 °C, increasing significantly polyphenol yield, as well as the ferric-reducing power and antiradical activity of the extracts. It was also proven that extraction with m-β-CD was the least energy-demanding process. Liquid chromatography-tandem mass spectrometry examination revealed that m-β-CD might possess higher affinity for luteolin 7-O-glucuronide extraction, but β-CD for rosmarinic acid extraction. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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18 pages, 1997 KiB  
Communication
Effect of Hippophae rhamnoides L. Leaves Treatment on the Antioxidant Capacity, Total Phenol Content and Sensory Profile of Moschofilero Wines Vinified with and without Added Sulphites
by Alexandros Tzachristas, Konstantina Pasvanka, Maria Liouni, Antony C. Calokerinos, Panagiotis Tataridis and Charalampos Proestos
Appl. Sci. 2020, 10(10), 3444; https://doi.org/10.3390/app10103444 - 16 May 2020
Cited by 7 | Viewed by 2423
Abstract
This study evaluated the antioxidant capacity, total phenol content, and sensory profile of selected Greek wines made from Vitis vinifera L. c.v. Moschofilero in two consecutive vintages, treated with powdered Hippophae rhamnoides L. leaves (HRL). Radical Scavenging activity, reducing power, total phenol content [...] Read more.
This study evaluated the antioxidant capacity, total phenol content, and sensory profile of selected Greek wines made from Vitis vinifera L. c.v. Moschofilero in two consecutive vintages, treated with powdered Hippophae rhamnoides L. leaves (HRL). Radical Scavenging activity, reducing power, total phenol content (TPC), and color intensity increased in a linear manner in relation to HRL treatments. Indicatively the addition of 0.8 g/L of HRL increased the radical scavenging activity as determined via the inhibition of the 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical from 28.4 to 55.8% in comparison to the initial values. Equally the reducing power as determined by the ferric reducing antioxidant power (FRAP) assay increased from 35.3 to 62.1%, and total phenol content values increased from 11% to 23.7% and the color intensity increased from 39.9 to 50.7%. The main oenological attributes examined, remained unchanged after the HRL addition. The addition of up to 0.4 g/L of HRL did not have a major impact on the organoleptic characteristics of the wines tasted whereas concentrations higher than 0.8 g/L were not considered beneficial. Results denote that the addition of H. rhamnoides leaves to white wines contributes positively to the overall antioxidant capacity and could be used if authorized as an antioxidant agent in wines vinified in the absence of or in synergy with sulphur dioxide. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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10 pages, 2407 KiB  
Article
Effects of Infusion and Storage on Antioxidant Activity and Total Phenolic Content of Black Tea
by Min-Yun Chang, Yin-Yi Lin, Yu-Chia Chang, Wen-Ying Huang, Wen-Shin Lin, Cheng-You Chen, Shu-Ling Huang and Yung-Sheng Lin
Appl. Sci. 2020, 10(8), 2685; https://doi.org/10.3390/app10082685 - 13 Apr 2020
Cited by 34 | Viewed by 5393
Abstract
This study determined antioxidant activity in terms of the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging ability and total phenolic content of black tea under different infusion and storage conditions. High performance liquid chromatography analysis identified caffeine, (−)-epigallocatechin, (−)-epicatechin-3-gallate, (−)-epigallocatechin-3-gallate and (−)-gallocatechin-3-gallate in the tea sample. The [...] Read more.
This study determined antioxidant activity in terms of the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging ability and total phenolic content of black tea under different infusion and storage conditions. High performance liquid chromatography analysis identified caffeine, (−)-epigallocatechin, (−)-epicatechin-3-gallate, (−)-epigallocatechin-3-gallate and (−)-gallocatechin-3-gallate in the tea sample. The water–tea leaves weight ratio did not affect the DPPH scavenging ability. However, infusion temperature affected the DPPH scavenging activity and the total phenolic content. In the present study, the 50% inhibitory concentrations (IC50) for DPPH of black tea infused at 60 to 100 °C ranged from 100.0 ± 13.7 to 28.4 ± 4.8 μg/mL. The total phenolic content of black tea steeped at 60 to 100 °C ranged from 50.4 ± 5.2 to 178.6 ± 16.4 mg gallic acid equivalent/g dry leaf. Black tea exhibited increased antioxidant activity when the infusion temperature was increased. Regarding short-term storage, the DPPH scavenging ability and total phenolic content of black tea did not significantly change within 15 days. This result was consistent for storage temperatures of 4, 9, and 25 °C. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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10 pages, 1390 KiB  
Article
Antiphotoaging Effect of (2′S)-Columbianetin from Corydalis heterocarpa in UVA-Irradiated Human Dermal Fibroblasts
by Jung Hwan Oh, Fatih Karadeniz, Jung Im Lee, Hye Ran Kim, Youngwan Seo and Chang-Suk Kong
Appl. Sci. 2020, 10(7), 2568; https://doi.org/10.3390/app10072568 - 9 Apr 2020
Cited by 5 | Viewed by 2233
Abstract
Ultraviolet A (UVA)-induced detrimental effects in the skin, also known as photoaging, are mediated with several pathways including oxidative stress generation and extracellular matrix (ECM) degradation. UVA irradiation results in excessive production of matrix metalloproteinases (MMPs), enzymes responsible for the degradation of ECM [...] Read more.
Ultraviolet A (UVA)-induced detrimental effects in the skin, also known as photoaging, are mediated with several pathways including oxidative stress generation and extracellular matrix (ECM) degradation. UVA irradiation results in excessive production of matrix metalloproteinases (MMPs), enzymes responsible for the degradation of ECM components such as collagen. In this study, the protective effects of (2′S)-columbianetin against UVA-induced changes in matrix metalloproteinase-1 (MMP-1) and collagen production were investigated in human dermal fibroblasts (HDFs). The (2′S)-columbianetin was isolated from Corydalis heterocarpa. UVA exposure increased MMP-1 release from HDFs and diminished the release of type I pro-collagen. Treatment with (2′S)-columbianetin reversed these effects of UVA exposure. The (2′S)-columbianetin treatment also suppressed the intracellular expression of MMP-1 and increased type I pro-collagen expression. UVA exposure elevated the activation of p38, c-Jun-amino-terminal kinase (JNK) and extracellular signal-related kinase (ERK) as the mechanism to stimulate MMP-1 production. The (2′S)-columbianetin suppressed the phosphorylation of JNK and ERK. The (2′S)-columbianetin was also stimulated collagen production via TGFβ signaling cascade, relieving UVA-induced suppression of Smad2/3 phosphorylation and translocation. In conclusion, (2′S)-columbianetin was suggested to be a potential cosmeceutical lead compound with antiphotoaging properties against UVA-induced collagen degradation. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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14 pages, 1283 KiB  
Article
Evaluation of Antioxidant Activity, Toxicity, and Phenolic Profile of Aqueous Extracts of Chamomile (Matricaria chamomilla L.) and Sage (Salvia officinalis L.) Prepared at Different Temperatures
by Nefeli S. Sotiropoulou, Stiliani F. Megremi and Petros Tarantilis
Appl. Sci. 2020, 10(7), 2270; https://doi.org/10.3390/app10072270 - 26 Mar 2020
Cited by 39 | Viewed by 6494
Abstract
Chamomile and sage are common herbs that are mostly used as infusions due to their beneficial properties. The aims of this study were to determine the total phenolic content, antioxidant activity, and potential toxicity of chamomile and sage aqueous extracts prepared at three [...] Read more.
Chamomile and sage are common herbs that are mostly used as infusions due to their beneficial properties. The aims of this study were to determine the total phenolic content, antioxidant activity, and potential toxicity of chamomile and sage aqueous extracts prepared at three different temperatures (25, 80, 100 °C) and finally, to detect their phenolic profiles at the optimum temperature. In order to measure the total phenolic content and antioxidant capacity, Folin–Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) assays were applied, respectively. The extraction temperature at 80 °C was the optimum, with maximal antioxidant activity and the highest total phenolic content for both herbs. Luminescence-based assay demonstrated that all the examined aqueous extracts possessed toxicity towards Vibrio fischeri. Microtox assay demonstrated no correlation with the other two assays, which were positively correlated. The major phenolics of chamomile were rutin trihydrate, ferulic acid, chlorogenic acid, and apigenin-7-O-glucoside; and major phenolics of sage were rosmarinic acid, salvianolic acid K, and luteolin-7-O-glucuronide, as defined by LC-MS of aqueous extracts at 80 °C. It can be concluded that the extraction of herbal aqueous extracts at 80 °C can provide significant bioactive and antioxidant compounds, but their consumption must be in moderation. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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8 pages, 1842 KiB  
Article
Anti-Cancer Activity of Catechin against A549 Lung Carcinoma Cells by Induction of Cyclin Kinase Inhibitor p21 and Suppression of Cyclin E1 and P–AKT
by Haiyan Sun, Meichen Yin, Danqing Hao and Yixiao Shen
Appl. Sci. 2020, 10(6), 2065; https://doi.org/10.3390/app10062065 - 19 Mar 2020
Cited by 34 | Viewed by 3270
Abstract
Catechin is one of the major polyphenols in teas, beans, and berry fruits. A number of studies have confirmed that catechins extract possesses health benefits in the prevention of various chronic diseases. In this study, the anti-cancer activity and mechanism of catechin against [...] Read more.
Catechin is one of the major polyphenols in teas, beans, and berry fruits. A number of studies have confirmed that catechins extract possesses health benefits in the prevention of various chronic diseases. In this study, the anti-cancer activity and mechanism of catechin against non-small cell lung cancer A549 cells were investigated. The inhibitory rate of catechin on the proliferation of A549 cells reached 19.76% at a concentration of 600 μmol·L−1 with 24 h incubation. The results demonstrated that catechin inhibits A549 cells by increasing the expressions of p21 and p27 in the cancer cells. Furthermore, the catechin treatment inhibited the expressions of cyclin E1 and phosphorylation of protein kinase (P–AKT) in a dose-dependent manner, which also contributed to the inhibition of cancer cell proliferation. Therefore, the results of this study indicated that catechin can effectively inhibit the proliferation of A549 cells through regulating its cell cycle arrest or indirectly via the p21 signaling pathway. It would provide important information for developing catechin and catechin-rich functional food or co-therapy for antitumor purposes. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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11 pages, 644 KiB  
Article
Antioxidant Activity and Polyphenolic Content of North Macedonian Wines
by Katerina Mitrevska, Spyros Grigorakis, Sofia Loupassaki and Antony C. Calokerinos
Appl. Sci. 2020, 10(6), 2010; https://doi.org/10.3390/app10062010 - 16 Mar 2020
Cited by 25 | Viewed by 3760
Abstract
The purpose of this study was to evaluate comparatively the polyphenolic content and the antioxidant activity of selected regional red and white wine varieties, produced in the Republic of North Macedonia. The polyphenolic content was evaluated by measuring the total polyphenol, total flavonoid, [...] Read more.
The purpose of this study was to evaluate comparatively the polyphenolic content and the antioxidant activity of selected regional red and white wine varieties, produced in the Republic of North Macedonia. The polyphenolic content was evaluated by measuring the total polyphenol, total flavonoid, total tannin and total anthocyanin contents and the antioxidant activity by applying the DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric-reducing antioxidant power) and CUPRAC (cupric ion-reducing antioxidant capacity) assays. Statistical analysis of the results showed that all white wines examined (Smederevka, Temjanika and Zhilavka) belong to the same group, two red wines (Vranec and Kratoshija) belong to another group while the Stanushina red variety shows distinct differences from the other red wines examined. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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10 pages, 629 KiB  
Article
Study on the Chemical Composition, Enzyme Inhibition and Antioxidant Activity of Ziziphora taurica subsp. cleonioides
by Cengiz Sarikurkcu, Eleni Kakouri, Rifat Tayyib Sarikurkcu and Petros A. Tarantilis
Appl. Sci. 2019, 9(24), 5515; https://doi.org/10.3390/app9245515 - 15 Dec 2019
Cited by 9 | Viewed by 2937
Abstract
Ziziphora is a plant used in Turkish and Iran traditional medicine for its antibacterial activity, sedative and stomach soothing properties. Although the chemical profile of the essential oil of different Ziziphora species is well documented, data regarding plant extracts are incomplete. In this [...] Read more.
Ziziphora is a plant used in Turkish and Iran traditional medicine for its antibacterial activity, sedative and stomach soothing properties. Although the chemical profile of the essential oil of different Ziziphora species is well documented, data regarding plant extracts are incomplete. In this study extracts from Ziziphora taurica subsp. cleonioides were obtained using ethyl acetate, methanol and water and the chemical profile of the aerial part of the plant was elucidated. Among the compounds identified, rosmarinic acid was the most abundant (3375.67 ± 38.02 μg/mL), at the extract of methanol, followed by chlorogenic acid (3225.10 ± 16.44). Enzyme inhibition activity against α-amylase and tyrosinase was also estimated. The ethyl acetate extract showed the highest α-amylase activity (1.95 ± 0.04 mg/mL), while the best anti-tyrosinase activity was calculated for the methanolic extract (1.25 ± 0.01 mg/mL). In addition, total phenolic, flavonoid content and antioxidant activity were evaluated. According to our results, bioactivity of the plant is of great interest, nonetheless, at the same time, it is strongly depended on the solvent used during the extraction process. Our data suggest that the plant under study may be an important source to consider against metabolic, skin pigmentation and oxidative stress related disorders. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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13 pages, 2281 KiB  
Article
Species-Specific Antioxidant Power and Bioactive Properties of the Extracts Obtained from Wild Mediterranean Calendula Spp. (Asteraceae)
by Concetta Maria Messina, Angelo Troia, Rosaria Arena, Simona Manuguerra, Theodora Ioannou, Eleonora Curcuraci, Giuseppe Renda, Claire Hellio and Andrea Santulli
Appl. Sci. 2019, 9(21), 4627; https://doi.org/10.3390/app9214627 - 31 Oct 2019
Cited by 20 | Viewed by 3052
Abstract
In this study we focused on four taxa of the genus Calendula (C. maritima, C. suffruticosa subsp. fulgida, C. arvensis, and the hybrid between the first two ones), collected in Mediterranean area (Sicily). Six extracts for each species were obtained [...] Read more.
In this study we focused on four taxa of the genus Calendula (C. maritima, C. suffruticosa subsp. fulgida, C. arvensis, and the hybrid between the first two ones), collected in Mediterranean area (Sicily). Six extracts for each species were obtained using solvents with increasing polarity (hexane, ethanol 80%, acetone 70%, and water) and through extraction by supercritical fluids (SFE). It has been observed that the solvent with the highest extraction efficiency was ethanol 80% for all species. However, SFE extracts showed high antioxidant activity comparable to the ethanol 80% extract (polyphenol, DPPH, and reducing power method). These findings were confirmed by in vitro analysis (MTT assay) where it was observed that the tested concentration (24 µg/mL), obtained from ethanol 80% and SFE extracts, showed a protective effect comparable to that induced by a synthetic antioxidant. Extraction with SFE ensured a great selectivity by avoiding the use of toxic organic solvents and thus consisted of a promising technique for sustainable production of Calendula extracts. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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14 pages, 3313 KiB  
Article
Effects of Glazing with Preservatives on the Quality Changes of Squid during Frozen Storage
by Mingtang Tan, Peiyun Li, Wenhui Yu, Jinfeng Wang and Jing Xie
Appl. Sci. 2019, 9(18), 3847; https://doi.org/10.3390/app9183847 - 13 Sep 2019
Cited by 42 | Viewed by 3286
Abstract
This study aimed to investigate the effects of glazing with sodium polyacrylate (SP) and D-sodium erythorbate (DSE) on the quality changes of squid during frozen storage. Frozen squid samples were randomly divided into seven groups: (1) CK (unglazed); (2) WG (distilled water-glazed); (3) [...] Read more.
This study aimed to investigate the effects of glazing with sodium polyacrylate (SP) and D-sodium erythorbate (DSE) on the quality changes of squid during frozen storage. Frozen squid samples were randomly divided into seven groups: (1) CK (unglazed); (2) WG (distilled water-glazed); (3) SG (0.1% SP -glazed); (4) SG-1DSE (0.1% SP with 0.1% DSE -glazed); (5) SG-3DSE (0.1% SP with 0.3% DSE-glazed); (6) SG-5DSE (0.1% SP with 0.5% DSE-glazed); (7) WG-1DSE (0.1% DSE-glazed). The efficacy of the different coatings was evaluated using various indicators, such as water holding capacity (WHC), pH value, low field nuclear magnetic resonance (LF-NMR), color, malondialdehyde (MDA) content value, free amino acids (FAAs) content, intrinsic fluorescence intensity (IFI) and the total sulfhydryl content (SH) content. Intrinsic fluorescence intensity (IFI) and low field nuclear magnetic resonance (LF-NMR) were used as fast monitoring techniques to monitor changes in quality of squid samples. The results showed that compared with the CK and WG groups, coating with either SG or DSE alone resulted in reduced rate of moisture loss (p < 0.05), lipid oxidation (p < 0.05) protein degradation (p < 0.05) and prolonged its shelf-life. The combination of glazing treatment with SG and DSE (groups SG-1DSE, SG-3DSE and SG-5DSE) further improved the protective effects of coating, particularly in the SG-3DSE group. Therefore, the glazing of SG-3DSE is recommended to be used to control the quality of frozen squid and to prolong its shelf-life during frozen storage. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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Review

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28 pages, 2226 KiB  
Review
Polyphenols: Natural Antioxidants to Be Used as a Quality Tool in Wine Authenticity
by Alexandros Tzachristas, Konstantina Pasvanka, Antony Calokerinos and Charalampos Proestos
Appl. Sci. 2020, 10(17), 5908; https://doi.org/10.3390/app10175908 - 26 Aug 2020
Cited by 16 | Viewed by 3918
Abstract
Polyphenols are a diverse group of compounds possessing various health-promoting properties that are of utmost importance for many wine sensory attributes. Apart from genetic and environmental parameters, the implementation of specific oenological practices as well as the subsequent storage conditions deeply affect the [...] Read more.
Polyphenols are a diverse group of compounds possessing various health-promoting properties that are of utmost importance for many wine sensory attributes. Apart from genetic and environmental parameters, the implementation of specific oenological practices as well as the subsequent storage conditions deeply affect the content and nature of the polyphenols present in wine. However, polyphenols are effectively employed in authenticity studies. Provision of authentic wines to the market has always been a prerequisite meaning that the declarations on the wine label should mirror the composition and provenance of this intriguing product. Nonetheless, multiple cases of intentional or unintentional wine mislabeling have been recorded alarming wine consumers who demand for strict controls safeguarding wine authenticity. The emergence of novel platforms employing instrumentation of exceptional selectivity and sensitivity along with the use of advanced chemometrics such as NMR (nuclear magnetic resonance)- and MS (mass spectrometry)-based metabolomics is considered as a powerful asset towards wine authentication. Full article
(This article belongs to the Special Issue Antioxidants in Natural Products)
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