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Antioxidant and Protective Effects of Plant Extracts

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A special issue of Antioxidants (ISSN 2076-3921). This special issue belongs to the section "Extraction and Industrial Applications of Antioxidants".

Deadline for manuscript submissions: closed (29 February 2024) | Viewed by 13503

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Special Issue Editors

Dr. Natale Badalamenti

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Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, 90128 Palermo, Italy
Interests: bioactive natural products; phytochemistry; medicinal natural products; structural modification; structural identification
Special Issues, Collections and Topics in MDPI journals

Dr. Adriana Basile

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Department of Biology, University of Naples Federico II, 80126 Naples, Italy
Interests: plant natural products; secondary metabolites; antibacterial activity; antioxidant activity; antitumoral activity; microscopy; protection against environmental stresses
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Medicinal plants, aromatic and wild herbs, in their different parts (roots, stems, stems, flowers, seeds, etc.) have been used since ancient times not only as flavoring additives and food preservatives, but the active ingredients contained therein are also the cornerstones of traditional medicine and ethnomedicine. Over the years, volatile compounds such as the terpenoids of essential oils; or secondary non-volatile metabolites extractable from the different parts, such as flavonoids, limonoids, triterpenoids, alkaloids, and polyphenols, have shown different antioxidant, protective, antimicrobial, antiproliferative, and anti-inflammatory effects. The growing concern about antibiotic resistance, as well as the skepticism of the world population towards the use of synthetic substances within the food supply chain and the growing attention towards the use of secondary metabolites to achieve a good lifestyle, have increasingly strengthened the importance of scientific opinion towards natural products. Based on countless scientific research, plant extracts such as essential oils or non-volatile extracts could help in terms of reducing microbial effects, ensuring safety, preserving food products, protecting against foreign agents such as metals, and exerting an antioxidant effect on human health. Therefore, the purpose of this Special Issue is to provide readers with a wide range of innovative scientific articles or original reviews, highlighting developments with respect to the past, and to stress biological and chemical advances in the application of plant extracts and essential oils as antioxidants and protective agents.

Dr. Natale Badalamenti
Dr. Adriana Basile
Guest Editors

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Keywords

essential oils
plant and food extracts
antioxidant
anti-inflammatory
antimicrobial
protective effects
antiproliferative

Published Papers (14 papers)

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Research

15 pages, 4149 KiB

Open AccessArticle

Corilagin Inhibits Neutrophil Extracellular Trap Formation and Protects against Hydrochloric Acid/Lipopolysaccharide-Induced Acute Lung Injury in Mice by Suppressing the STAT3 and NOX2 Signaling Pathways

by Fu-Chao Liu, Huang-Ping Yu, Chia-Chih Liao, An-Hsun Chou and Hung-Chen Lee

Antioxidants 2024, 13(4), 491; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13040491 - 19 Apr 2024

Viewed by 233

Abstract

Acute lung injury (ALI) and its severe manifestation, acute respiratory distress syndrome (ARDS), are characterized by uncontrolled inflammatory responses, neutrophil activation and infiltration, damage to the alveolar capillary membrane, and diffuse alveolar injury. Neutrophil extracellular traps (NETs), formed by activated neutrophils, contribute significantly to various inflammatory disorders and can lead to tissue damage and organ dysfunction. Corilagin, a compound found in Phyllanthus urinaria, possesses antioxidative and anti-inflammatory properties. In this study, we investigated the protective effects and underlying mechanisms of corilagin in hydrochloric acid (HCl)/lipopolysaccharide (LPS)-induced lung injury. Mice received intraperitoneal administration of corilagin (2.5, 5, or 10 mg/kg) or an equal volume of saline 30 min after intratracheal HCl/LPS administration. After 20 h, lung tissues were collected for analysis. Corilagin treatment significantly mitigated lung injury, as evidenced by reduced inflammatory cell infiltration, decreased production of proinflammatory cytokines, and alleviated oxidative stress. Furthermore, corilagin treatment suppressed neutrophil elastase expression, reduced NET formation, and inhibited the expression of ERK, p38, AKT, STAT3, and NOX2. Our findings suggest that corilagin inhibits NET formation and protects against HCl/LPS-induced ALI in mice by modulating the STAT3 and NOX2 signaling pathways. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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23 pages, 4720 KiB

Open AccessArticle

The Neuroprotective Flavonoids Sterubin and Fisetin Maintain Mitochondrial Health under Oxytotic/Ferroptotic Stress and Improve Bioenergetic Efficiency in HT22 Neuronal Cells

by Marie Goujon, Zhibin Liang, David Soriano-Castell, Antonio Currais and Pamela Maher

Antioxidants 2024, 13(4), 460; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13040460 - 13 Apr 2024

Viewed by 508

Abstract

The global increase in the aging population has led to a rise in many age-related diseases with continuing unmet therapeutic needs. Research into the molecular mechanisms underlying both aging and neurodegeneration has identified promising therapeutic targets, such as the oxytosis/ferroptosis cell death pathway, in which mitochondrial dysfunction plays a critical role. This study focused on sterubin and fisetin, two flavonoids from the natural pharmacopeia previously identified as strong inhibitors of the oxytosis/ferroptosis pathway. Here, we investigated the effects of the compounds on the mitochondrial physiology in HT22 hippocampal nerve cells under oxytotic/ferroptotic stress. We show that the compounds can restore mitochondrial homeostasis at the level of redox regulation, calcium uptake, biogenesis, fusion/fission dynamics, and modulation of respiration, leading to the enhancement of bioenergetic efficiency. However, mitochondria are not required for the neuroprotective effects of sterubin and fisetin, highlighting their diverse homeostatic impacts. Sterubin and fisetin, thus, provide opportunities to expand drug development strategies for anti-oxytotic/ferroptotic agents and offer new perspectives on the intricate interplay between mitochondrial function, cellular stress, and the pathophysiology of aging and age-related neurodegenerative disorders. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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17 pages, 3054 KiB

Open AccessArticle

Unravelling the Influence of Chlorogenic Acid on the Antioxidant Phytochemistry of Avocado (Persea americana Mill.) Fruit Peel

by Gloria O. Izu, Emmanuel Mfotie Njoya, Gaetan T. Tabakam, Jennifer Nambooze, Kgalaletso P. Otukile, Seiso E. Tsoeu, Victoria O. Fasiku, Ayodeji M. Adegoke, Ochuko L. Erukainure, Samson S. Mashele, Tshepiso J. Makhafola, Mamello P. Sekhoacha and Chika I. Chukwuma

Antioxidants 2024, 13(4), 456; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13040456 - 12 Apr 2024

Viewed by 435

Abstract

Oxidative stress is pivotal in the pathology of many diseases. This study investigated the antioxidant phytochemistry of avocado (Persea americana Mill.) peel. Different solvent extracts (dichloromethane, ethyl acetate, methanol, and water) of avocado peel were subjected to total phenol and flavonoid quantification, as well as in vitro radical scavenging and ferric reducing evaluation. The methanol extract was subjected to gradient column chromatographic fractionation. Fraction 8 (eluted with hexane:chloroform:methanol volume ratio of 3:6.5:0.5, respectively) was subjected to LC-MS analysis. It was assessed for cellular inhibition of lipid peroxidation and lipopolysaccharide (LPS)-induced ROS and NO production. The DPPH radical scavenging mechanism of chlorogenic acid was investigated using Density Functional Theory (DFT). The methanol extract and fraction 8 had the highest phenol content and radical scavenging activity. Chlorogenic acid (103.5 mg/mL) and 1-O-caffeoylquinic acid (102.3 mg/mL) were the most abundant phenolics in the fraction. Fraction 8 and chlorogenic acid dose-dependently inhibited in vitro (IC₅₀ = 5.73 and 6.17 µg/mL) and cellular (IC₅₀ = 15.9 and 9.34 µg/mL) FeSO₄-induced lipid peroxidation, as well as LPS-induced ROS (IC₅₀ = 39.6 and 28.2 µg/mL) and NO (IC₅₀ = 63.5 and 107 µg/mL) production, while modulating antioxidant enzyme activity. The fraction and chlorogenic acid were not cytotoxic. DFT analysis suggest that an electron transfer, followed by proton transfer at carbons 3′OH and 4′OH positions may be the radical scavenging mechanism of chlorogenic acid. Considering this study is bioassay-guided, it is logical to conclude that chlorogenic acid strongly influences the antioxidant capacity of avocado fruit peel. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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21 pages, 4217 KiB

Open AccessArticle

Phytochemical Characterization, Antioxidant, and Anti-Proliferative Activities of Wild and Cultivated Nigella damascena Species Collected in Sicily (Italy)

by Monica Scognamiglio, Viviana Maresca, Adriana Basile, Severina Pacifico, Antonio Fiorentino, Maurizio Bruno, Natale Badalamenti, Marta Kapelusz, Pasquale Marino, Lucia Capasso, Paola Bontempo and Giuseppe Bazan

Antioxidants 2024, 13(4), 402; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13040402 - 27 Mar 2024

Viewed by 556

Abstract

The use of Nigella damascena seeds in the culinary field or as aerial parts infusions in the pharmaceutical and cosmetic fields is widely reported. The biological activity of this plant, as demonstrated over the years, is closely related to its phytochemical content. This investigation focused on the comparative study of the same plants of N. damascena, one totally wild (WND), while the other two, one with white flowers (CWND) and the other with blue flowers (CBND), were subject to cultivation, irrigation, and manual weeding. Using the potential of 1D and 2D-NMR spectroscopy, coupled with MS/MS spectrometric studies, the three methanolic extracts of N. damascena were investigated. Chemical studies have highlighted the presence of triterpene saponin compounds and various glycosylated flavonoids. Finally, the in vitro antiproliferative and antioxidant activities of the three individual extracts were evaluated. The antiproliferative activity performed on U-937, HL-60, and MCF-7 tumor cell lines highlighted a greater anticancer effect of the CBND and CWND extracts compared to the data obtained using WND. The antioxidant activity, however, performed to quantify ROS generation is comparable among the extracts used. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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16 pages, 3011 KiB

Open AccessArticle

Phytochemical Characterization and Antibacterial Activity of Albanian Juniperus communis and Juniperus oxycedrus Berries and Needle Leaves Extracts

by Ilir Mërtiri, Bogdan Păcularu-Burada and Nicoleta Stănciuc

Antioxidants 2024, 13(3), 345; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13030345 - 13 Mar 2024

Viewed by 863

Abstract

This paper aims to investigate the phytochemical profile and in vitro antibacterial activity of two juniper species collected in Albania, Juniperus communis and Juniperus oxycedrus. The berries and the needle leaves were subjected to solid–liquid solvent ultrasound-assisted extraction. The phytochemical characterization of the extracts was performed by spectrophotometric and chromatographic means. The extract of J. communis berries (JcB) showed a higher total phenolic and flavonoid content (3.04 ± 0.09 mg GAE/g DW, and 1.14 ± 0.36 mg QE/g DW, respectively), also a higher antioxidant activity from DPPH and ABTS radical screening assays, compared to J. oxycedrus berries (JoxB) extract. The extract of J. oxycedrus needle leaves (JoxL) prevailed in total flavonoid content (10.55 ± 0.24 mg QE/g DW), and ABTS assays (1.83 ± 0.01 mM TE/g DW), compared to the extract of J. communis needle leaves (JcL). The chromatographic analysis revealed the presence of ellagic acid and kaempferol in all the samples. Ellagic acid was the main identified compound with the highest quantity in the extracts of JoxB, JoxL, and JcB with an average of 445.69 ± 0.96 µg/g, 2890.05 ± 0.29 µg/g, and 8133.83 ± 4.03 µg/g, respectively. The antibacterial potential of the ethanolic extracts was evaluated on Bacillus spp., Escherichia coli, and Staphylococcus aureus. In the Agar Well Diffusion Assay, it was observed that all the tested bacterial strains were sensitive to the extracts, whereas selected extracts showed a similar inhibition activity rate compared with the antibiotic substance (Chloramphenicol), used as a positive control. The extracts showed a similar minimal inhibitory and bactericidal concentration for the individual bacterial strains, suggesting that J. communis and J. oxycedrus extracts have a similar potential in antibacterial activity. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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16 pages, 3020 KiB

Open AccessArticle

Anti-Inflammatory Effects of Anthocyanin-Enriched Black Soybean Seed Coat (BSSC) Crude Extract on LPS-Induced Acute Liver Injury in Mice

by Yu-Tang Tung, Chun-Liang Tung, Cheng-Chia Hsieh, Yu-Chen Huang, Shiming Li, Chun-Liang Tung and Jyh-Horng Wu

Antioxidants 2024, 13(3), 311; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13030311 - 01 Mar 2024

Viewed by 914

Abstract

Soybeans rank among the top five globally produced crops. Black soybeans contain anthocyanins in their seed coat, offering strong antioxidant and anti-inflammatory benefits. This study explores the protective effects of black soybean seed coat (BSSC) against acute liver injury (ALI) in mice. Mice pretreated with BSSC crude extract showed reduced liver damage, inflammation, and apoptosis. High doses (300 mg/kg) of the extract decreased levels of proinflammatory cytokines (IL-6, IFN-γ) and increased levels of anti-inflammatory ones (IL-4, IL-10), alongside mitigating liver pathological damage. Additionally, it influenced the Nrf2/HO-1 pathway and reduced levels of apoptosis-related proteins. In vitro, the compounds delphinidin-3-O-glucoside (D3G) and cyanidin-3-O-glucoside (C3G) in BSSC were found to modulate cytokine levels, suggesting their role in ALI protection. The study concludes that BSSC extract, particularly due to D3G and C3G, effectively protects against LPS-induced ALI in mice by inhibiting inflammation, oxidative stress, and apoptosis. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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18 pages, 2720 KiB

Open AccessArticle

Onion (Allium cepa L.) Skin Waste Valorization: Unveiling the Phenolic Profile and Biological Potential for the Creation of Bioactive Agents through Subcritical Water Extraction

by Esther Trigueros, Óscar Benito-Román, Andreia P. Oliveira, Romeu A. Videira, Paula B. Andrade, María Teresa Sanz and Sagrario Beltrán

Antioxidants 2024, 13(2), 205; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13020205 - 05 Feb 2024

Viewed by 948

Abstract

Onion skin waste (OSW), the primary non-edible byproduct from onion processing, offers a renewable source of bioactive compounds. This study aims to valorize OSW through subcritical water extraction (SWE), aligning with a circular economy and biorefinery principles. SWE was carried out at 145 °C and 50 bar for 50 min in a discontinuous reactor, producing a phenolic-rich extract (32.3 ± 2.6 mg/g) dominated by protocatechuic acid (20.3 ± 2.5 mg/g), quercetin-4′-O-glucoside (7.5 ± 0.2 mg/g), and quercetin (3.2 ± 0.6 mg/g). Additionally, the extract contains sugars (207.1 ± 20.3 mg sucrose-Eq/g), proteins (22.8 ± 1.6 mg BSA-Eq/g), and free amino acids (20.4 ± 1.2 mg arginine-Eq/g). Its phenolic richness determines its scavenging activity against ^●NO and O₂^●− radicals and its α-glucosidase and aldose-reductase inhibition without affecting α-amylase. Notably, the extract demonstrates significant α-glucosidase inhibition (IC₅₀ = 75.6 ± 43.5 µg/mL), surpassing acarbose (IC₅₀ = 129.5 ± 1.0 µg/mL) in both pure enzyme and cell culture tests without showing cytotoxicity to AGS, HepG2, and Caco-2 human cell lines. The extract’s bioactivity and nutritional content make it suitable for developing antioxidant and antidiabetic nutraceutical/food components, highlighting SWE’s potential for OSW valorization without using organic solvents. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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15 pages, 4170 KiB

Open AccessArticle

Molecular Docking Studies and In Vitro Activity of Paliurus spina-christi Mill Extracts as Pancreatic Lipase Inhibitors

by Fedora Grande, Mariangela Marrelli, Valentina Amodeo, Maria Antonietta Occhiuzzi, Iulia Pinzaru, Mary Fucile, Cristina Adriana Dehelean, Ersilia Alexa, Filomena Conforti and Giancarlo Statti

Antioxidants 2024, 13(2), 160; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13020160 - 26 Jan 2024

Viewed by 819

Abstract

Obesity is a risk factor for the onset of chronic diseases. One of the most promising approaches to treating obesity consists of reducing dietary fat absorption using extracts from plants because they contain phenolic compounds, especially flavonoids. Paliurus spina-christi, belonging to the Rhamnaceae family, is one of the five species belonging to the Paliurus genus. Herein, the aerial parts of the plant were extracted with methanol through the pressurized cyclic solid-liquid extraction using the Naviglio extractor^®. The extracts were analyzed with High Performance Thin Layer Chromatography and investigated for their in vitro biological potential. The phytochemical analysis revealed that rutin has been shown to be the most abundant flavonoid component. The best antiradical activity was observed for the fruit extract with an IC₅₀ value of 53.41 ± 1.24 µg/mL. This extract also has a better inhibitory capacity on lipid peroxidation evaluated at a different time of incubation. Potent lipase inhibitor activity of the extract from fruits was also demonstrated with in vitro experiments. This property can be attributed to a direct interaction of main components of P. spina-christi extract with the human pancreatic enzyme as demonstrated by the results of molecular docking experiments conducted on the crystallographic structures of lipase. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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14 pages, 2215 KiB

Open AccessArticle

Redox State Modulatory Activity and Cytotoxicity of Olea europaea L. (Oleaceae) Leaves Extract Enriched in Polyphenols Using Macroporous Resin

by Tonia Luca, Giuseppe Antonio Malfa, Laura Siracusa, Alfonsina La Mantia, Simone Bianchi, Edoardo Napoli, Stefano Puleo, Angelo Sergi, Rosaria Acquaviva and Sergio Castorina

Antioxidants 2024, 13(1), 73; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13010073 - 04 Jan 2024

Viewed by 1164

Abstract

The food products derived from Olea europaea are a fundamental part of the Mediterranean diet, and their health-promoting effects are well known. In this study, we analyzed the phytochemical characteristics, the redox state modulatory activity, and the cytotoxic effect of an olive leaf aqueous extract enriched by macroporous resin on different tumor and normal cell lines (LNCaP, PC3, HFF-1). HPLC-DAD analysis, the Folin–Ciocalteu and aluminum chloride methods confirmed the qualitatively and quantitatively high content of phenolic compounds (130.02 ± 2.3 mg GAE/g extract), and a DPPH assay (IC₅₀ = 100.00 ± 1.8 μg/mL), the related antioxidant activity. The biological investigation showed a significant cytotoxic effect, highlighted by an MTT test and the evident cellular morphological changes, on two prostate cancer cell lines. Remarkably, the extract was practically non-toxic on HFF-1 at the concentrations (100, 150, 300 µg/mL) and exposure times tested. Hence, the results are selective for tumor cells. The underlying cytotoxicity was associated with the decrease in ROS production (55% PC3, 42% LNCaP) and the increase in RSH levels (>50% PC3) and an LDH release assay (50% PC3, 40% LNCaP, established necrosis as the main cell death mechanism. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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25 pages, 1855 KiB

Open AccessArticle

Unraveling Biotic and Abiotic Factors Shaping Sugarcane Straw Polyphenolic Richness: A Gateway to Artificial Intelligence-Driven Crop Management

by Ana L. S. Oliveira, Maria João Carvalho, Poliana Silva, Manuela Pintado and Ana Raquel Madureira

Antioxidants 2024, 13(1), 47; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox13010047 - 27 Dec 2023

Viewed by 853

Abstract

Sugarcane straw (Saccharum officinarum) is a valuable coproduct renowned for its abundant polyphenolic content. However, extracting these polyphenols for natural ingredients faces challenges due to their inherent variability, influenced by biotic stress factors and plant characteristics. We explored the impact of five crucial factors on sugarcane straw polyphenolic diversity: (i) production area (Guariba, Valparaíso), (ii) borer insect (Diatraea saccharalis) infestation, (iii) plant age (first to seventh harvest), (iv) harvest season, and (v) plant variety. Response surface methodology (RSM) and artificial neural networks (ANN) were used to optimize polyphenol extraction conditions. A second-order polynomial model guided us to predict ideal sugarcane straw harvesting conditions for polyphenol-rich extracts. The analysis identified CU0618-variety straw, harvested in Guariba during the dry season (October 2020), at the seventh harvest stage, with 13.81% borer insect infection, as the prime source for high hydroxybenzoic acid (1010 µg/g), hydroxycinnamic acid (3119 µg/g), and flavone (573 µg/g) content and consequently high antioxidant capacity. The ANN model surpasses the RSM model, demonstrating superior predictive capabilities with higher coefficients of determination and reduced mean absolute deviations for each polyphenol class. This underscores the potential of artificial neural networks in forecasting and enhancing polyphenol extraction conditions, setting the stage for AI-driven advancements in crop management. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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16 pages, 1947 KiB

Open AccessArticle

Chemical Composition of Salvia fruticosa Mill. Essential Oil and Its Protective Effects on Both Photosynthetic Damage and Oxidative Stress in Conocephalum conicum L. Induced by Environmental Heavy Metal Concentrations

by Natale Badalamenti, Giovanna Salbitani, Piergiorgio Cianciullo, Rosanna Bossa, Francesca De Ruberto, Valeria Greco, Adriana Basile, Viviana Maresca, Maurizio Bruno and Simona Carfagna

Antioxidants 2023, 12(11), 1990; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox12111990 - 11 Nov 2023

Viewed by 1008

Abstract

The genus Salvia L., belonging to the Lamiaceae family, contains more than 900 species distributed in various parts of the world. It is a genus containing aromatic plants used both in the culinary field and above all in the cosmetic area to produce several perfumes. Salvia fruticosa Mill., notoriously known as Greek Salvia, is a plant used since ancient times in traditional medicine, but today cultivated and used in various parts of Europe and Africa. Polar and apolar extracts of this plant confirmed the presence of several metabolites such as abietane and labdane diterpenoids, triterpenoids, steroids, and some flavonoids, causing interesting properties such as sedative, carminative, and antiseptic, while its essential oils (EOs) are mainly characterized by compounds such as 1,8-cineole and camphor. The aim of this work concerns the chemical analysis by GC and GC-MS, and the investigation of the biological properties, of the EO of S. fruticosa plants collected in eastern Sicily. The gas-chromatographic analysis confirmed the presence of 1,8-cineole (17.38%) and camphor (12.81%), but at the same time, also moderate amounts of α-terpineol (6.74%), β-myrcene (9.07%), camphene (8.66%), β-pinene (6.55%), and α-pinene (6.45%). To study the protective effect of EOs from S. fruticosa (both the total mixture and the individual compounds) on possible damage induced by heavy metals, an in vitro system was used in which a model organism, the liverwort Conocephalum conicum, was subjected to the effect of a mix of heavy metals (HM) prepared using values of concentrations actually measured in one of the most polluted watercourses of the Campania region, the Regi Lagni. Finally, the antioxidant response and the photosynthetic damage were examined. The exogenous application of the EO yields a resumption of the oxidative stress induced by HM, as demonstrated by the reduction in the Reactive Oxygen Species (ROS) content and by the increased activity of antioxidant enzyme catalase (CAT) and glutathione-S-transferase (GST). Furthermore, plants treated with HMs and EO showed a higher F_v/F_m (maximal quantum efficiency of PSII in the dark) with respect to HMs-only treated ones. These results clearly indicate the protective capacity of the EO of S. fruticosa against oxidative stress, which is achieved at least in part by modulating the redox state through the antioxidant pathway and on photosynthetic damage. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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14 pages, 1774 KiB

Open AccessArticle

LED Lights Influenced Phytochemical Contents and Biological Activities in Kale (Brassica oleracea L. var. acephala) Microgreens

by Seom Lee, Chang Ha Park, Jin Kyung Kim, Kyungmin Ahn, Haejin Kwon, Jae Kwang Kim, Sang Un Park and Hyeon Ji Yeo

Antioxidants 2023, 12(9), 1686; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox12091686 - 29 Aug 2023

Cited by 4 | Viewed by 1287

Abstract

Light-emitting diodes (LEDs) are regarded as an effective artificial light source for producing sprouts, microgreens, and baby leaves. Thus, this study aimed to investigate the influence of different LED lights (white, red, and blue) on the biosynthesis of secondary metabolites (glucosinolates, carotenoids, and phenolics) and the biological effects on kale microgreens. Microgreens irradiated with white LEDs showed higher levels of carotenoids, including lutein, 13-cis-β-carotene, α-carotene, β-carotene, and 9-cis-β-carotene, than those irradiated with red or blue LEDs. These findings were consistent with higher expression levels of carotenoid biosynthetic genes (BoPDS and BoZDS) in white-irradiated kale microgreens. Similarly, microgreens irradiated with white and blue LEDs showed slightly higher levels of glucosinolates, including glucoiberin, progoitrin, sinigrin, and glucobrassicanapin, than those irradiated with red LEDs. These results agree with the high expression levels of BoMYB28-2, BoMYB28-3, and BoMYB29 in white- and blue-irradiated kale microgreens. In contrast, kale microgreens irradiated with blue LEDs contained higher levels of phenolic compounds (gallic acid, catechin, ferulic acid, sinapic acid, and quercetin). According to the total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition assays, the extracts of kale microgreens irradiated with blue LEDs had slightly higher antioxidant activities, and the DPPH inhibition percentage had a positive correlation with TPC in the microgreens. Furthermore, the extracts of kale microgreens irradiated with blue LEDs exhibited stronger antibacterial properties against normal pathogens and multidrug-resistant pathogens than those irradiated with white and red LEDs. These results indicate that white-LED lights are suitable for carotenoid production, whereas blue-LED lights are efficient in increasing the accumulation of phenolics and their biological activities in kale microgreens. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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26 pages, 3017 KiB

Open AccessArticle

Improvement in the Biosynthesis of Antioxidant-Active Metabolites in In Vitro Cultures of Isatis tinctoria (Brassicaceae) by Biotechnological Methods/Elicitation and Precursor Feeding

by Natalizia Miceli, Inga Kwiecień, Noemi Nicosia, Jasmine Speranza, Salvatore Ragusa, Emilia Cavò, Federica Davì, Maria Fernanda Taviano and Halina Ekiert

Antioxidants 2023, 12(5), 1111; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox12051111 - 17 May 2023

Cited by 1 | Viewed by 1352

Abstract

This study aimed to establish the in vitro shoot culture of Isatis tinctoria L. and its ability to produce antioxidant bioactive compounds. The Murashige and Skoog (MS) medium variants, containing different concentrations (0.1–2.0 mg/L) of benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) were tested. Their influence on the growth of biomass, accumulation of phenolic compounds, and antioxidant potential was evaluated. To improve the phenolic content, agitated cultures (MS 1.0/1.0 mg/L BAP/NAA) were treated with different elicitors, including the following: Methyl Jasmonate, CaCl₂, AgNO₃, and yeast, as well as with L-Phenylalanine and L-Tyrosine—precursors of phenolic metabolites. The total phenolic content (TPC) of hydroalcoholic extracts (MeOH 70%) obtained from the biomass grown in vitro was determined spectrophotometrically; phenolic acids and flavonoids were quantified by RP-HPLC. Moreover, the antioxidant potential of extracts was examined through the DPPH test, the reducing power, and the Fe²⁺ chelating assays. The biomass extracts obtained after 72 h of supplementation with Tyr (2 g/L), as well as after 120 and 168 h with Tyr (1 g/L), were found to be the richest in TPC (49.37 ± 0.93, 58.65 ± 0.91, and 60.36 ± 4.97 mg GAE/g extract, respectively). Whereas among the elicitors, the highest TPC achieved was with CaCl₂ (20 and 50 mM 24 h), followed by MeJa (50 and 100 µM, 120 h). The HPLC of the extracts led to the identification of six flavonoids and nine phenolic acids, with vicenin-2, isovitexin, syringic, and caffeic acids being the most abundant compounds. Notably, the amount of all flavonoids and phenolic acids detected in the elicited/precursor feeding biomass was higher than that of the leaves of the parental plant. The best chelating activity was found with the extract of biomass fed with Tyrosine 2 g/L, 72 h (IC₅₀ 0.27 ± 0.01 mg/mL), the strongest radical scavenging (DPPH test) for the extract obtained from biomass elicited with CaCl₂ 50 mM, after 24 h of incubation (25.14 ± 0.35 mg Trolox equivalents (TE)/g extract). In conclusion, the in vitro shoot culture of I. tinctoria supplemented with Tyrosine, as well as MeJa and/or CaCl₂, could represent a biotechnological source of compounds with antioxidant properties. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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Open AccessArticle

Hydrogen Protection Boosts the Bioactivity of Chrysanthemum morifolium Extract in Preventing Palmitate-Induced Endothelial Dysfunction by Restoring MFN2 and Alleviating Oxidative Stress in HAEC Cells

by Yilin Gao, Oumeng Song, Min Wang, Xin Guo, Guanfei Zhang, Xuyun Liu, Jiankang Liu and Lin Zhao

Antioxidants 2023, 12(5), 1019; https://0-doi-org.brum.beds.ac.uk/10.3390/antiox12051019 - 28 Apr 2023

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Abstract

As the most important natural antioxidants in plant extracts, polyphenols demonstrate versatile bioactivities and are susceptible to oxidation. The commonly used ultrasonic extraction often causes oxidation reactions involving the formation of free radicals. To minimize the oxidation effects during the ultrasonic extraction process, we designed a hydrogen (H₂)-protected ultrasonic extraction method and used it in Chrysanthemum morifolium extraction. Hydrogen-protected extraction improved the total antioxidant capacity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and polyphenol content of Chrysanthemum morifolium water extract (CME) compared with air and nitrogen (N₂) conditions. We further investigated the protective effects and mechanisms of CME on palmitate (PA)-induced endothelial dysfunction in human aorta endothelial cells (HAECs). We found that hydrogen-protected CME (H₂-CME) best-prevented impairment in nitric oxide (NO) production, endothelial NO synthase (eNOS) protein level, oxidative stress, and mitochondrial dysfunction. In addition, H₂-CME prevented PA-induced endothelial dysfunction by restoring mitofusin-2 (MFN2) levels and maintaining redox balance. Full article

(This article belongs to the Special Issue Antioxidant and Protective Effects of Plant Extracts)

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