scholarly journals Revisiting the Oxidation of Flavonoids: Loss, Conservation or Enhancement of Their Antioxidant Properties

Antioxidants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 133
Author(s):  
Hernan Speisky ◽  
Fereidoon Shahidi ◽  
Adriano Costa de Camargo ◽  
Jocelyn Fuentes
Keyword(s):  
Antioxidant Capacity ◽  
Antioxidant Properties ◽  
Oxidative Modification ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
High Susceptibility ◽  
Comprehensive Description ◽  
Health Promoting ◽  
Endogenous Antioxidant ◽  
Electrophilic Character

Flavonoids display a broad range of health-promoting bioactivities. Among these, their capacity to act as antioxidants has remained most prominent. The canonical reactive oxygen species (ROS)-scavenging mode of the antioxidant action of flavonoids relies on the high susceptibility of their phenolic moieties to undergo oxidation. As a consequence, upon reaction with ROS, the antioxidant capacity of flavonoids is severely compromised. Other phenol-compromising reactions, such as those involved in the biotransformation of flavonoids, can also markedly affect their antioxidant properties. In recent years, however, increasing evidence has indicated that, at least for some flavonoids, the oxidation of such residues can in fact markedly enhance their original antioxidant properties. In such apparent paradoxical cases, the antioxidant activity arises from the pro-oxidant and/or electrophilic character of some of their oxidation-derived metabolites and is exerted by activating the Nrf2–Keap1 pathway, which upregulates the cell’s endogenous antioxidant capacity, and/or, by preventing the activation of the pro-oxidant and pro-inflammatory NF-κB pathway. This review focuses on the effects that the oxidative and/or non-oxidative modification of the phenolic groups of flavonoids may have on the ability of the resulting metabolites to promote direct and/or indirect antioxidant actions. Considering the case of a metabolite resulting from the oxidation of quercetin, we offer a comprehensive description of the evidence that increasingly supports the concept that, in the case of certain flavonoids, the oxidation of phenolics emerges as a mechanism that markedly amplifies their original antioxidant properties. An overlooked topic of great phytomedicine potential is thus unraveled.

scholarly journals Quality of New Functional Powdered Beverages Enriched with Lyophilized Fruits—Potentially Bioaccessible Antioxidant Properties, Nutritional Value, and Consumer Analysis

2020 ◽  
Vol 10 (11) ◽  
pp. 3668 ◽  
Author(s):  
Justyna Bochnak-Niedźwiecka ◽  
Michał Świeca
Keyword(s):  
Antioxidant Capacity ◽  
Raw Materials ◽  
Antioxidant Properties ◽  
Reducing Power ◽  
In Vitro Digestion ◽  
In Vitro Bioaccessibility ◽  
Trolox Equivalent ◽  
Health Promoting

This study evaluates nutrients and health-promoting compounds responsible for antioxidant capacity in eight novel formulations based on lyophilized fruit and vegetable powders. The composition contained lyophilized carrot, pumpkin, lentil sprouts, raspberry, strawberry, and apple. The effect of functional additives on the antioxidant, nutritional, and functional characteristics of powdered beverages was determined in the powders and after rehydration followed by in vitro digestion. The antioxidant activity, phenols, vitamin C, and reducing power were significantly higher in the powders enriched with additives having potential functional properties. Furthermore, the analyses indicated that all the powdered formulations may be potential sources of total starch (100–112 mg/100 mL) and proteins (125–139 mg/100 mL). The designed powdered beverages after reconstitution exhibited high antioxidant content, reasonable consumer acceptance, and good in vitro bioaccessibility. The best results of antioxidant capacity were obtained for beverages enriched with raspberry, i.e., 10.4 mg Trolox equivalent (TE)/100 mL and 12.1 mg TE/100 mL rehydrated at 20 °C and 80 °C, respectively. Additionally, color characteristics were used as indicators of the quality of the powdered beverages. This research promotes the reduction of food waste, since whole plant tissues are used, thus allowing maximum exploitation of food raw materials; moreover, drying provides stable shelf life.

scholarly journals Antioxidant and food additive BHA prevents TNF cytotoxicity by acting as a direct RIPK1 inhibitor

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Tom Delanghe ◽  
Jon Huyghe ◽  
Seungheon Lee ◽  
Dario Priem ◽  
Samya Van Coillie ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
In Silico Analysis ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Cellular Processes ◽  
Silico Analysis ◽  
Surprising Finding ◽  
Necrosis Factor ◽  
In Cells

AbstractButylate hydroxyanisole (BHA) is a synthetic phenol that is widely utilized as a preservative by the food and cosmetic industries. The antioxidant properties of BHA are also frequently used by scientists to claim the implication of reactive oxygen species (ROS) in various cellular processes, including cell death. We report on the surprising finding that BHA functions as a direct inhibitor of RIPK1, a major signaling hub downstream of several immune receptors. Our in silico analysis predicts binding of 3-BHA, but not 2-BHA, to RIPK1 in an inactive DLG-out/Glu-out conformation, similar to the binding of the type III inhibitor Nec-1s to RIPK1. This predicted superior inhibitory capacity of 3-BHA over 2-BHA was confirmed in cells and using in vitro kinase assays. We demonstrate that the reported protective effect of BHA against tumor necrosis factor (TNF)-induced necroptotic death does not originate from ROS scavenging but instead from direct RIPK1 enzymatic inhibition, a finding that most probably extends to other reported effects of BHA. Accordingly, we show that BHA not only protects cells against RIPK1-mediated necroptosis but also against RIPK1 kinase-dependent apoptosis. We found that BHA treatment completely inhibits basal and induced RIPK1 enzymatic activity in cells, monitored at the level of TNFR1 complex I under apoptotic conditions or in the cytosol under necroptosis. Finally, we show that oral administration of BHA protects mice from RIPK1 kinase-dependent lethality caused by TNF injection, a model of systemic inflammatory response syndrome. In conclusion, our results demonstrate that BHA can no longer be used as a strict antioxidant and that new functions of RIPK1 may emerge from previously reported effects of BHA.

Antioxidant Capacity, Phytochemical Analysis and Identification of Active Compounds in Anchomanes difformis

2020 ◽  
Vol 10 (4) ◽  
pp. 446-458 ◽  
Author(s):  
Toyin Dorcas Alabi ◽  
Nicole Lisa Brooks ◽  
Oluwafemi Omoniyi Oguntibeju
Keyword(s):  
Antioxidant Capacity ◽  
Bioactive Compounds ◽  
Microbial Growth ◽  
Antioxidant Properties ◽  
Natural Antioxidants ◽  
Therapeutic Agents ◽  
Phytochemical Analysis ◽  
Flavonoid Content ◽  
The Family ◽  
Health Promoting

Background: Anchomanes difformis (ENGL: Blume) is a specie of flowering plants in the family Araceae. Anchomanes difformis is commonly reported for ameliorating hyperglycemia, inflammation, ulcer, malaria, and inhibiting microbial growth. Objective: This study evaluated total yields of phytochemicals present, measured antioxidant capacities and identified bioactive compounds in the leaves and rhizome extracts of A. difformis using solvents of different polarity (ethyl acetate, ethanol and water). Methods: Total polyphenolic, flavonoid content and alkaloids were measured, ORAC, TEAC and FRAP were performed as antioxidant capacity indices, and identification of bioactive compounds was done using UPLC-MS and HPLC. Results: All extracts contained polyphenols, flavonols, flavanols, and alkaloids in varying concentrations. All extracts exhibited antioxidant properties. However, aqueous leaves extract had the highest antioxidant properties and polyphenols with significance (p<0.05). Thirty-four compounds were identified altogether in the leaves and rhizome. Conclusion: A. difformis leaves and rhizome are potential sources of natural antioxidants and can serve as potential therapeutic agents against diseases linked with oxidative stress. Presence of health-promoting compounds indicates possible ameliorative potentials of A. difformis.

scholarly journals Therapies with Antioxidant Potential in Psoriasis, Vitiligo, and Lichen Planus

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1087
Author(s):  
Fabrizio Guarneri ◽  
Lucrezia Bertino ◽  
Giovanni Pioggia ◽  
Marco Casciaro ◽  
Sebastiano Gangemi
Keyword(s):  
Lichen Planus ◽  
Inflammatory Diseases ◽  
Antioxidant Properties ◽  
Antioxidant Systems ◽  
Oxygen Species ◽  
Standard Drug ◽  
Drug Treatments ◽  
Endogenous Antioxidant ◽  
Clinical Changes

Oxidative stress plays an important pathogenetic role in many chronic inflammatory diseases, including those of dermatological interest. In particular, regarding psoriasis, vitiligo, and lichen planus, excess reactive oxygen species and a decline in endogenous antioxidant systems are observed. In this regard, treatments with antioxidant properties could be appropriate therapeutic options. To date, clinical trials in dermatology on these treatments are limited. We reviewed the available studies on the efficacy of antioxidant therapies in psoriasis, vitiligo, and lichen planus. The role of herbal derivatives, vitamins, and trace elements was analyzed. The antioxidant properties of conventional therapies were also evaluated. Data from the literature suggest that antioxidants might be useful, but available studies on this topic are limited, heterogeneous, not completely standardized, and on small populations. Furthermore, in most cases, antioxidants alone are unable to induce significant clinical changes, except perhaps in mild forms, and must be used in conjunction with standard drug treatments to achieve measurable results. Further studies need to be conducted, considering larger populations and using internationally validated scales, in order to compare the results and clinical efficacy.

scholarly journals Multivitamin and Mineral Supplementation Containing Phytonutrients Scavenges Reactive Oxygen Species in Healthy Subjects: A Randomized, Double-Blinded, Placebo-Controlled Trial

Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 101 ◽  
Author(s):  
Seunghee Kang ◽  
Yeni Lim ◽  
You Jin Kim ◽  
Eun Sung Jung ◽  
Dong Ho Suh ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Dna Damage ◽  
Fruits And Vegetables ◽  
Controlled Trial ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Double Blind ◽  
Mineral Supplementation ◽  
Endogenous Antioxidant

Phytonutrients and vitamin and mineral supplementation have been reported to provide increased antioxidant capacity in humans; however, there is still controversy. In the current clinical trial, we examined the antioxidant and DNA protection capacity of a plant-based, multi-vitamin/mineral, and phytonutrient (PMP) supplementation in healthy adults who were habitually low in the consumption of fruits and vegetables. This study was an eight-week, double-blind, randomized, parallel-arm, and placebo-controlled trial. PMP supplementation for eight weeks reduced reactive oxygen species (ROS) and prevented DNA damage without altering endogenous antioxidant system. Plasma vitamins and phytonutrients were significantly correlated with ROS scavenging and DNA damage. In addition, gene expression analysis in PBMC showed subtle changes in superoxide metabolic processes. In this study, we showed that supplementation with a PMP significantly improved ROS scavenging activity and prevented DNA damage. However, additional research is still needed to further identify mechanisms of actions and the role of circulating phytonutrient metabolites.

scholarly journals Mesoporous Polydopamine Nanoparticles Attenuate Morphine Tolerance in Neuropathic Pain Rats by Inhibition of Oxidative Stress and Restoration of the Endogenous Antioxidant System

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 195
Author(s):  
Yaswanth Kuthati ◽  
Prabhakar Busa ◽  
Srikrishna Tummala ◽  
Vaikar Navakanth Rao ◽  
Venkata Naga Goutham Davuluri ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Neuropathic Pain ◽  
Pain Management ◽  
Liver Enzymes ◽  
Histopathological Examination ◽  
Drug Loading ◽  
Antioxidant Properties ◽  
Ros Scavenging ◽  
Endogenous Antioxidant

Oxidative stress resulting from reactive oxygen species (ROS) is known to play a key role in numerous neurological disorders, including neuropathic pain. Morphine is one of the commonly used opioids for pain management. However, long-term administration of morphine results in morphine antinociceptive tolerance (MAT) through elevation of ROS and suppression of natural antioxidant defense mechanisms. Recently, mesoporous polydopamine (MPDA) nanoparticles (NPS) have been known to possess strong antioxidant properties. We speculated that morphine delivery through an antioxidant nanocarrier might be a reasonable strategy to alleviate MAT. MPDAs showed a high drug loading efficiency of ∼50%, which was much higher than conventional NPS. Spectral and in vitro studies suggest a superior ROS scavenging ability of NPS. Results from a rat neuropathic pain model demonstrate that MPDA-loaded morphine (MPDA@Mor) is efficient in minimizing MAT with prolonged analgesic effect and suppression of pro-inflammatory cytokines. Additionally, serum levels of liver enzymes and levels of endogenous antioxidants were measured in the liver. Treatment with free morphine resulted in elevated levels of liver enzymes and significantly lowered the activities of endogenous antioxidant enzymes in comparison with the control and MPDA@Mor-treated group. Histopathological examination of the liver revealed that MPDA@Mor can significantly reduce the hepatotoxic effects of morphine. Taken together, our current work will provide an important insight into the development of safe and effective nano-antioxidant platforms for neuropathic pain management.

scholarly journals A Polyphenol-Rich Extract From Entada abyssinica Reduces Oxidative Damage in Cryopreserved Ram Semen

2020 ◽  
Vol 7 ◽  
Author(s):  
Mansour Sobeh ◽  
Soha A. Hassan ◽  
Mahmoud A. E. Hassan ◽  
Wael A. Khalil ◽  
Mohamed A. O. Abdelfattah ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Folk Medicine ◽  
Membrane Integrity ◽  
Bark Extract ◽  
Oxygen Species ◽  
Polyphenol Content ◽  
Progressive Motility ◽  
Total Antioxidant ◽  
Endogenous Antioxidant

The Splinter bean, Entada abyssinica, is widely used in folk medicine. In the current work, we profiled the secondary metabolites from E. abyssinica bark extract using LC-MS and investigated its effect on cryopreserved ram semen. Twenty-eight compounds, including tannins and gallic acid derivatives that prevailed in the extract, were tentatively identified. Results showed that the quality of the post-thawed semen showed a significant improvement when the extract was added to the extender at a concentration of 375 μg/mL. The progressive motility and plasma membrane integrity of sperm cells were significantly increased in the post-thawed semen; however, the total antioxidant capacity (TAC) was insignificantly increased. A significant decrease in the concentration of hydrogen peroxide was detected as well. No significant changes were observed in activities of lactate dehydrogenase (LDH), alanine aminotransaminase (ALT), and aspartate transaminase (AST) within the treated samples. Intact sperm percentage was significantly increased, while apoptotic and necrotic sperm percentages were reduced significantly. Molecular docking of some individual components from the extract revealed their potential to interfere with the apoptosis cascade in which Bcl-2 is involved. In conclusion, Entada abyssinica appears to be useful for cryopreservation presumably owing to its polyphenol content that has potent antioxidant capacity scavenging reactive oxygen species (ROS), enhancing the endogenous antioxidant system and inhibiting lipid peroxidation.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Amentoflavone: A Bifunctional Metal Chelator that Controls the Formation of Neurotoxic Soluble Aβ42 Oligomers

2020 ◽  
Author(s):  
Liang Sun ◽  
Anuj K. Sharma ◽  
Byung-Hee Han ◽  
Liviu M. Mirica
Keyword(s):  
Reactive Oxygen Species ◽  
Metal Ions ◽  
Antioxidant Properties ◽  
Reactive Oxygen ◽  
Amyloid Plaques ◽  
Transition Metal Ions ◽  
Oxygen Species ◽  
High Affinity ◽  
Amyloid Aβ ◽  
Β Amyloid

<p>Alzheimer's disease (AD) is the most common neurodegenerative disorder, yet the cause and progression of this disorder are not completely understood. While the main hallmark of AD is the deposition of amyloid plaques consisting of the β-amyloid (Aβ) peptide, transition metal ions are also known to play a significant role in disease pathology by expediting the formation of neurotoxic soluble β-amyloid (Aβ) oligomers, reactive oxygen species (ROS), and oxidative stress. Thus, bifunctional metal chelators that can control these deleterious properties are highly desirable. Herein, we show that amentoflavone (AMF) – a natural biflavonoid compound, exhibits good metal-chelating properties, especially for chelating Cu<sup>2+</sup> with very high affinity (pCu<sub>7.4</sub> = 10.44). In addition, AMF binds to Aβ fibrils with a high affinity (<i>K<sub>i</sub></i> = 287 ± 20 nM) – as revealed by a competition thioflavin T (ThT) assay, and specifically labels the amyloid plaques <i>ex vivo</i> in the brain sections of transgenic AD mice – as confirmed via immunostaining with an Ab antibody. The effect of AMF on Aβ<sub>42</sub> aggregation and disaggregation of Aβ<sub>42</sub> fibrils was also investigated, to reveal that AMF can control the formation of neurotoxic soluble Aβ<sub>42</sub> oligomers, both in absence and presence of metal ions, and as confirmed via cell toxicity studies. Furthermore, an ascorbate consumption assay shows that AMF exhibits potent antioxidant properties and can chelate Cu<sup>2+</sup> and significantly diminish the Cu<sup>2+</sup>-ascorbate redox cycling and reactive oxygen species (ROS) formation. Overall, these studies strongly suggest that AMF acts as a bifunctional chelator that can interact with various Aβ aggregates and reduce their neurotoxicity, can also bind Cu<sup>2+</sup> and mediate its deleterious redox properties, and thus AMF has the potential to be a lead compound for further therapeutic agent development for AD. </p>

HPLC Screening of Bioactives Compounds and Antioxidant Capacity of Different Hypericum Species

2018 ◽  
Vol 69 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Daniela Gitea ◽  
Simona Vicas ◽  
Manuel Alexandru Gitea ◽  
Sebastian Nemeth ◽  
Delia Mirela Tit ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Methanol Extract ◽  
Antioxidant Properties ◽  
Polyphenolic Compounds ◽  
The Other ◽  
The North ◽  
Western Area ◽  
North Western ◽  
Hypericum Species ◽  
Biological Actions

Our study compares the content in polyphenolic compounds and hypericin, in four species of Hypericum - H. perforatum L., H. maculatum Cr., H. hirsutum L., H. tetrapterum Fr. (syn. Hypericumacutum Mnch.) harvested from spontaneous flora in the north-western area of Transylvania, Romania. These species represent an important source of such compounds with different biological actions. After making the extracts, they were subjected to HPLC-SM analysis. The presence of rutoside in the largest amount (462.82 mg %) in the H. perforatum extract was observed, this containing most of the flavonoid heterosides. For the species H. maculatum, the presence in a much higher amount of the hyperoside (976.36 mg %) is characteristic compared to the other species. Quercetol is the best represented of the flavonoid aglycons, its concentration being the highest in H. hirsutum (659.66 mg %). The hypericin content ranges from 0.2171 g % in the H. tetrapterum extract, to 0.0314 g % in the methanol extract of H. maculatum.The highest antioxidant properties measured by FRAP method were recorded in the case of H. perforatum and H. maculatum.

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