Hepatic Nrf2 expression is altered by quercetin supplementation in X-irradiated rats

New perspectives on the therapeutic potential of quercetin in non-communicable diseases: Targeting Nrf2 to counteract oxidative stress and inflammation

Non-communicable diseases (NCDs), including cardiovascular diseases, cancer, metabolic diseases, and skeletal diseases, pose significant challenges to public health worldwide. The complex pathogenesis of these diseases is closely linked to oxidative stress and inflammatory damage. Nuclear factor erythroid 2-related factor 2 (Nrf2), a critical transcription factor, plays an important role in regulating antioxidant and anti-inflammatory responses to protect the cells from oxidative damage and inflammation-mediated injury. Therefore, Nrf2-targeting therapies hold promise for preventing and treating NCDs. Quercetin (Que) is a widely available flavonoid that has significant antioxidant and anti-inflammatory properties. It modulates the Nrf2 signaling pathway to ameliorate oxidative stress and inflammation. Que modulates mitochondrial function, apoptosis, autophagy, and cell damage biomarkers to regulate oxidative stress and inflammation, highlighting its efficacy as a therapeutic agent against NCDs. Here, we discussed, for the first time, the close association between NCD pathogenesis and the Nrf2 signaling pathway, involved in neurodegenerative diseases (NDDs), cardiovascular disease, cancers, organ damage, and bone damage. Furthermore, we reviewed the availability, pharmacokinetics, pharmaceutics, and therapeutic applications of Que in treating NCDs. In addition, we focused on the challenges and prospects for its clinical use. Que represents a promising candidate for the treatment of NCDs due to its Nrf2-targeting properties.

Beneficial Effect of Rosuvastatin Therapy on Spleen Injury Induced by Gamma Irradiation in Rats: Targeting Nrf2/EPRE Pathway

Purpose

The present study investigates the new approach of rosuvastatin (RUV) administration as a drug for the management of spleen injury induced by gamma irradiation.

Main Methods

Forty rats were used and divided equally into 4 groups: control group, irradiated group, IRR + rosuvastatin group (10 mg/Kg b. wt), and IRR + rosuvastatin group (20 mg/kg b. wt) for 7 days orally.

Results

The possible curative effect can be illustrated via the improvement of hematopoietic cell count (Hb, RBCs, and WBCs) and oxidative stress markers (MDA and GST) in addition to biochemical parameters including [heme oxigenase-1 (HO-1), nuclear erythroid 2-related factor (Nrf2), NOD-, LRR- and pyrin domain- containing protein 3 (NLRP3) inflammasome] and immune assay of nuclear factor kappa beta (NF-kB P65) and inducible nitric oxide synthase (iNOS). Histological pictures emphasize the biochemical findings. Rosuvastatin treatments by using two different doses improve the tested parameters. High-dose administration of RUV (20 mg/kg p.o.) recorded better results than the low dose (10 mg/kg p.o.).

Conclusion

Our results suggested that rosuvastatin reversed the radiation-induced spleen-damaging effects. So, RUV can be introduced to the market as a new therapy for the management of spleen damages.

Fruits and their phytochemicals in mitigating the ill effects of ionizing radiation: review on the existing scientific evidence and way forward

Although helpful in treating cancer, exposure to ionizing radiation can sometimes cause severe side effects, negating its benefit. In addition to its use in clinics, a nontoxic radioprotective agent can also be beneficial in occupational settings where humans are occupationally exposed for prolonged periods to low doses of radiation. Scientific studies using laboratory animals have shown that the fruits Aegle marmelos, Capsicum annuum, Citrus aurantium, Citrullus lanatus, Crataegus microphylla, Eugenia jambolana, Emblica officinalis, Garcinia kola, Grewia asiatica, Hippophae rhamnoides, Malus baccata, Malpighia glabra or Malpighia emarginata, Mangifera indica, Prunus domestica, Prunus avium, Prunus armeniaca, Psoralea corylifolia, Punica granatum, Solanum lycopersicum, Terminalia chebula, Vaccinium macrocarpon, Vitis vinifera and Xylopia aethiopica, and the phytochemicals gallic acid, ellagic acid, quercetin, geraniin, corilagin, ascorbic acid, hesperetin, ursolic acid, lycopene, naringin, hesperidin, rutin, resveratrol, β-sitosterol, apigenin, luteolin, chlorogenic acid, caffeic acid, mangiferin, diosmin, ferulic acid, and kaempferol are effective in preventing radiation-induced ill effects. Clinical studies with Emblica officinalis and Punica granatum have also shown that fruits help mitigate radiation-induced mucositis, dermatitis, and cystitis. For the first time, the current review summarizes the beneficial effects of fruits and phytochemicals in mitigating radiation-induced damage, the underlying mechanisms and the existing lacunae for future studies to be undertaken for the benefit of humans and the nutraceutical and agri-based industries.

Novel iodinated quinazolinones bearing sulfonamide as new scaffold targeting radiation induced oxidative stress

Reactive oxygen species (ROS) play an integral role in the pathogenesis of most diseases. This work presents the design and synthesis of fourteen new diiodoquinazolinone derivatives bearing benzenesulfonamide moiety with variable acetamide tail and evaluation of their ability to activate nuclear factor erythroid 2-related factor 2 (Nrf2) using its classical target NAD(P)H: quinone oxidoreductase 1 (NQO1) in Hepa1c1c7 murine hepatoma cells. The N-(2-chloropyridin-3-yl)-2-((6,8-diiodo-4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-yl)thio) acetamide 17 was the most potent NQO1 inducer (CD = 25 µM) with free radical scavenging activity (IC50 = 28 µM) and in vivo median lethal dose (LD50) of 500 mg/Kg. The possible radioprotective activity of compound 17 was evaluated in (7 Gy) irradiated mice. Compound 17 showed a reduction in radiation induced oxidative stress as evidenced by the lower levels of ROS, malondialdehyde (MDA) and NQO1 in liver tissues. Moreover, compound 17 showed improvement in the complete blood count (CBC) of irradiated mice and decreased mortality over 30 days following irradiation. Additionally, docking studies inside the Nrf2-binding site of Kelch-like ECH associated protein 1 (Keap1), the main negative regulator of Nrf2, confirmed that 17 revealed the same interactions with the key amino acids as those of the co-crystallized ligand. This study identifies 17 as a novel antioxidant that protects against the harmful effect of radiation.

Mild mitochondrial uncoupling protects from ionizing radiation induced cell death by attenuating oxidative stress and mitochondrial damage

Ionizing radiation (IR) induced mitochondrial dysfunction is associated with enhanced radiation stimulated metabolic oxidative stress that interacts randomly with intracellular bio-macromolecules causing lethal cellular injury and cell death. Since mild mitochondrial uncoupling emerged as a valuable therapeutic approach by regulating oxidative stress in most prevalent human diseases including ageing, ischemic reperfusion injury, and neurodegeneration with comparable features of IR inflicted mitochondrial damage. Therefore, we explored whether mitochondrial uncoupling could also protect from IR induced cytotoxic insult. Our results showed that DNP, BHT, FCCP, and BAM15 are safe to cells at different concentrations range depending on their respective mitochondrial uncoupling potential. Pre-incubation of murine fibroblast (NIH/3T3) cells with the safe concentration of these uncouplers followed by gamma (γ)-radiation showed significant cell growth recovery, reduced ROS generation, and apoptosis, compared to IR treatment alone. We observed that DNP pre-treatment increased the surviving fraction of IR exposed HEK-293, Raw 264.7 and NIH/3T3 cells. Additionally, DNP pre-treatment followed by IR leads to reduced total and mitochondrial oxidative stress (mos), regulated calcium (Ca²⁺) homeostasis, and mitochondrial bioenergetics in NIH/3T3 cells. It also significantly reduced macromolecular oxidation, correlated with the regulated ROS generation and antioxidant defence system. Moreover, DNP facilitated DNA repair kinetics evidenced by reducing the number of γ-H2AX foci formation and fragmented nuclei with time. DNP pre-incubation restrained the radiation induced pro-apoptotic factors and inhibits apoptosis. Our findings raise the possibility that mild mitochondrial uncoupling with DNP could be a potential therapeutic approach for radiation induced cytotoxic insult associated with an altered mitochondrial function.

Quercetin-conjugated superparamagnetic iron oxide nanoparticles (QCSPIONs) increases Nrf2 expression via miR-27a mediation to prevent memory dysfunction in diabetic rats

Oxidative stress is one of the earliest defects involved in the development of diabetes-induced cognitive impairment. Nrf2 is the master regulator of the cellular antioxidant system can be regulated by some microRNAs. The study aimed to evaluate the effects of quercetin (QC) and quercetin-conjugated superparamagnetic iron oxide nanoparticles (QCSPIONs) on Nrf2-controlled antioxidant genes through the redox-sensitive miR-27a. Expression levels of miR-27a, Nrf2, SOD1, GPX1, and CAT were measured by quantitative real-time PCR. Moreover, the oxidative stress parameters including total antioxidant capacity (TAC) and histological alterations were investigated. The expression level of miR-27a was significantly up-regulated in diabetic rats. While expression levels of Nrf2, SOD1, GPX1, and CAT were significantly down-regulated under diabetic condition. Interestingly, QCSPIONs decreased expression level of miR-27a and subsequently enhanced the expression levels of Nrf2, SOD1, and CAT to the control level. No significant difference was observed in the expression level of GPX1. Besides, QC in pure and especially conjugated form was able to normalize TAC and regenerate pathological lesions in STZ-diabetic rats. Our result demonstrates that QCSPIONs as an effective combined therapy can decrease miR-27a expression, which in turn increases the Nrf2 expression and responsive antioxidant genes, resulting in improvement of memory dysfunction in diabetic rats.

Radiomodulatory effect of a non-electrophilic NQO1 inducer identified in a screen of new 6, 8-diiodoquinazolin-4(3H)-ones carrying a sulfonamide moiety

Fifteen new quinazolinone derivatives bearing benzenesulfonamide moiety with variable acetamide tail were synthesized. The structures assigned to the products were concordant with the microanalytical and spectral data. Compounds 4-18 were screened for their ability to induce the antioxidant enzyme NAD(P)H: quinone oxidoreductase 1 (NQO1) in cells, a classical target for transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2). The 2-((6,8-diiodo-4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-yl)thio)-N-(3,4,5-trimethoxyphenyl) acetamide 15 showed the most potent NQO1 inducer activity in vitro. Compound 15 had low toxicity in mice (LD50 = 500 mg/kg). It also reduced the damaging effects of gamma radiation, as assessed by the levels of Nrf2, NQO1, reactive oxygen species (ROS) and malondialdehyde (MDA) in liver tissues. In addition, compound 15 showed amelioration in the complete blood count of irradiated mice and enhanced survival over a period of 30 days following irradiation. Molecular docking of 15 inside the Nrf2-binding site of Kelch-like ECH associated protein 1 (Keap1), the main negative regulator of Nrf2, showed the same binding interactions as that of the co-crystallized ligand considering the binding possibilities and energy scores. These findings suggest that compound 15 could be considered as a promising antioxidant and radiomodulatory agent.

Grape-Leaf Extract Attenuates Alcohol-Induced Liver Injury via Interference with NF-κB Signaling Pathway

Grape (Vitis vinifera) leaf extracts (GLEs) are known to be rich in phenolic compounds that exert potent antioxidant effects. Given the vulnerability of the liver to oxidative damage, antioxidants have been proposed as therapeutic agents and coadjuvant drugs to ameliorate liver pathologies. The current study was designed to characterize secondary metabolites and investigate the hepatoprotective effects of GLE and its underlying mechanisms. The secondary metabolites were profiled using HPLC–PDA–ESI-MS, and forty-five compounds were tentatively identified. In experimental in vivo design, liver injury was induced by oral administration of high doses of ethanol (EtOH) for 12 days to male Sprague Dawley rats that were split into five different groups. Blood samples and livers were then collected, and used for various biochemical, immunohistochemical, and histopathological analyses. Results showed that GLE-attenuated liver injury and promoted marked hepatic antioxidant effects, in addition to suppressing the increased heat-shock protein-70 expression. Moreover, GLE suppressed EtOH-induced expression of nuclear factor-κB (NF-κB) p65 subunit and proinflammatory cytokine tumor necrosis factor-α. Caspase-3 and survivin were enhanced by EtOH intake and suppressed by GLE intake. Finally, EtOH-induced histopathological changes in liver sections were markedly normalized by GLE. In conclusion, our results suggested that GLE interferes with NF-κB signaling and induces antioxidant effects, which both play a role in attenuating apoptosis and associated liver injury in a model of EtOH-induced liver damage in rats.

The effect of naringenin on the role of nuclear factor (erythroid-derived 2)-like2 (Nrf2) and haem oxygenase 1 (HO-1) in reducing the risk of oxidative stress-related radiotoxicity in the spleen of rats

The present study was to evaluate the radiomitigative effect of naringenin (NRG) on the modulation of ionizing radiation (IR)-induced spleen injury. Rats were exposed to 12 Gy (3Gy/two times/week). NRG (50mg/Kg), was orally given one hour after the first radiation dose, and daily continued during the irradiation period. Rats were sacrificed 1 day after the last dose of radiation. NRG showed a significant decrease of malondialdehyde, hydrogen peroxide with a significant elevation of superoxide dismutase, catalase and glutathione peroxidase activities and glutathione content. Moreover, NRG confirmed the intracellular defense mechanisms through activation of nuclear factor (erythroid-derived 2)-like2 (Nrf2) and haem oxygenase-1 (HO-1) levels and their protein expression. In addition, NRG deactivated the nuclear factor-κB (NF-κB) and reduced the pro-inflammatory cytokines. Further, NRG showed positive modulation in the haematological values (WBCs, RBCs, Hb, Hct% and PLt). In conclusion, these results suggested that NRG reversed the IR-induced redox-imbalance in the rat spleen.

Cholinergic and cytoprotective signaling cascades mediate the mitigative effect of erythropoietin on acute radiation syndrome

The present investigation aimed to evaluate the radiomitigative efficacy of the recombinant human erythropoietin (EPO) against acute radiation syndrome (ARS) in a rat model. Rats were irradiated with a single sublethal dose of γ-radiation (7 Gy; total body irradiation; TBI) on the 1st day of experimental course, then received EPO (5000 IU/kg; i.p.) 24 h after irradiation, and rats were observed for 30 days of survival analysis. Administration of EPO improved 30-day survival, alleviated TBI-induced myelosuppression and pancytopenia, by augmenting lymphocytes and other white blood cells in the peripheral blood of rats, while bone marrow and spleen cellularity were restored. EPO post-exposure treatment alleviated hepatotoxicity biomarkers and restored splenic function. EPO abrogated radiation-induced oxidative stress through the upregulation of the cholinergic anti-inflammatory nicotinic acetylcholine receptor (α-7-nAChR) and the pro-survival Janus kinase-2 and signal transducers and activators of transcription JAK-2/STAT-3 signaling mediated via enhancing nuclear factor erythroid-2 related factor-2 (Nrf-2) cytoprotective machinery in liver and spleen of irradiated rats. Moreover, EPO treatment prevented hepatic and splenic apoptosis. The present study establishes the implication of α-7-nAChR-JAK-2/STAT-3-Nrf-2 signaling cascade in the radiomitigative potential of EPO against ARS.

Quercetin Inhibits Peripheral and Spinal Cord Nociceptive Mechanisms to Reduce Intense Acute Swimming-Induced Muscle Pain in Mice

The present study aimed to evaluate the effects of the flavonoid quercetin (3,3´,4´,5,7-pentahydroxyflavone) in a mice model of intense acute swimming-induced muscle pain, which resembles delayed onset muscle soreness. Quercetin intraperitoneal (i.p.) treatment dose-dependently reduced muscle mechanical hyperalgesia. Quercetin inhibited myeloperoxidase (MPO) and N-acetyl-β-D- glucosaminidase (NAG) activities, cytokine production, oxidative stress, cyclooxygenase-2 (COX-2) and gp91^phox mRNA expression and muscle injury (creatinine kinase [CK] blood levels and myoblast determination protein [MyoD] mRNA expression) as well as inhibited NFκB activation and induced Nrf2 and HO-1 mRNA expression in the soleus muscle. Beyond inhibiting those peripheral effects, quercetin also inhibited spinal cord cytokine production, oxidative stress and glial cells activation (glial fibrillary acidic protein [GFAP] and ionized calcium-binding adapter molecule 1 [Iba-1] mRNA expression). Concluding, the present data demonstrate that quercetin is a potential molecule for the treatment of muscle pain conditions related to unaccustomed exercise.

Time-course and intensity-based classifications of oxidative stresses and their potential application in biomedical, comparative and environmental research

OBJECTIVE

We propose some clues for classification of oxidative stresses based on their intensity and time-course.

BACKGROUND

Oxidative stress is studied for more than three decades and it is clear that it may differ on the parameters of interest. But up to now there is no any system for formal discrimination between different types of the stress. Such approach can provide important benefits at description of experimental data.

METHOD

We briefly review information on oxidative stresses and show that the theoretical concept is actually poorly developed since introduction of the first definition in 1985 by H. Sies. We argue that the stresses can differ on their intensities and time-curses, but there was no theoretical basis for discrimination between them.

RESULTS

On the basis of these analyses, we propose two systems of classifications of oxidative stresses enabling their description taking into account their intensity and time-course. We analyze essential biomarkers of oxidative stress to be used for classification such as levels of modified by reactive oxygen species proteins, lipids, nucleic acids, and low molecular mass compounds. Finally, we describe potential applications of the proposed classifications to biomedical, comparative and environmental research.

CONCLUSION

The proposed classifications of oxidative stress may facilitate description of experimental data and their comparison between different organisms and methods of induction of oxidative stresses. Additionally this work may provide some clues to develop quantitative approaches for formal categorization of oxidative stresses.

APPLICATION

Most applications of the classifications proposed are theoretical and applied studies where oxidative stress takes place.

Modulation of Metabolic Detoxification Pathways Using Foods and Food-Derived Components: A Scientific Review with Clinical Application

Research into human biotransformation and elimination systems continues to evolve. Various clinical and in vivo studies have been undertaken to evaluate the effects of foods and food-derived components on the activity of detoxification pathways, including phase I cytochrome P450 enzymes, phase II conjugation enzymes, Nrf2 signaling, and metallothionein. This review summarizes the research in this area to date, highlighting the potential for foods and nutrients to support and/or modulate detoxification functions. Clinical applications to alter detoxification pathway activity and improve patient outcomes are considered, drawing on the growing understanding of the relationship between detoxification functions and different disease states, genetic polymorphisms, and drug-nutrient interactions. Some caution is recommended, however, due to the limitations of current research as well as indications that many nutrients exert biphasic, dose-dependent effects and that genetic polymorphisms may alter outcomes. A whole-foods approach may, therefore, be prudent.