scholarly journals Cinnamaldehyde Ameliorates Vascular Dysfunction in Diabetic Mice by Activating Nrf2

2020 ◽  
Vol 33 (7) ◽  
pp. 610-619 ◽  
Author(s):  
Peijian Wang ◽  
Yi Yang ◽  
Dan Wang ◽  
Qiyuan Yang ◽  
Jindong Wan ◽  
...  

Abstract BACKGROUND Oxidative stress is known to be associated with the development of diabetes. Cinnamaldehyde (CA) is a spice compound in cinnamon that enhances the antioxidant defense against reactive oxygen species (ROS) by activating nuclear factor erythroid-related factor 2 (Nrf2), which has been shown to have a cardioprotection effect. However, the relationship between CA and Nrf2 in diabetic vascular complications remains unclear. METHODS Leptin receptor-deficient (db/db) mice were fed normal chow or diet containing 0.02% CA for 12 weeks. The vascular tone, blood pressure, superoxide level, nitric oxide (NO) production, renal morphology, and function were measured in each group. RESULTS CA remarkably inhibited ROS generation, preserved NO production, increased phosphorylated endothelial nitric oxide synthase (p-eNOS), attenuated the upregulation of nitrotyrosine, P22 and P47 in aortas of db/db mice, and apparently ameliorated the elevation of type IV collagen, TGF-β1, P22, and P47 in kidney of db/db mice. Feeding with CA improved endothelium-dependent relaxation of aortas and mesenteric arteries, and alleviated the remodeling of mesenteric arteries in db/db mice. Additionally, dietary CA ameliorated glomerular fibrosis and renal dysfunction in diabetic mice. Nrf2 and its targeted genes heme oxygenase-1 (HO-1) and quinone oxidoreductase-1 (NQO-1) were slightly increased in db/db mice and further upregulated by CA. However, these protective effects of CA were reversed in Nrf2 downregulation mice. CONCLUSIONS A prolonged diet of CA protects against diabetic vascular dysfunction by inhibiting oxidative stress through activating of Nrf2 signaling pathway in db/db mice.

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jiayi Chen ◽  
Fangting He ◽  
Sijing Liu ◽  
Tao Zhou ◽  
Saira Baloch ◽  
...  

Ligustrum robustum is a traditional herbal tea that is widely distributed in southwest China. The health effects of L. robustum are characteristics of clearing heat, antioxidant, inducing resurgence, and improving digestion. However, the molecular mechanisms related to these effects, particularly the antioxidant mechanism, have been seldom reported. The objective of this study was to assess antioxidative capacity of L. robustum, and its protective effects and mechanisms against hydrogen peroxide (H2O2) - induced toxicity in Caco-2 cells. Total phenolic contents, free radical scavenging activity, and reducing capacity of L. robustum were measured. The effects of L. robustum on the cell viability and antioxidant defense system were explored. The expression of nuclear factor E2 related factor 2 (Nrf2) and antioxidant genes: quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), and glutamate cysteine ligase (GCL) were analyzed by western blot and qPCR. Pretreatment of L. robustum could significantly reduce H2O2-induced toxicity, decrease the level of reactive oxygen species (ROS) and malondialdehyde (MDA), and increase the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione reductase (GR). By activating the expression of Nrf2 and antioxidant genes (NQO1, HO-1, and GCL), L. robustum exerts cytoprotective effect in Caco-2 cells dealt with H2O2. Therefore, the well-established model of Caco-2 cells demonstrates that L. robustum may modulate the cytoprotective effect against the H2O2-induced oxidative stress through the Nrf2 signaling pathway.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 862
Author(s):  
Yi-Jen Peng ◽  
Jeng-Wei Lu ◽  
Chian-Her Lee ◽  
Herng-Sheng Lee ◽  
You-Hsiang Chu ◽  
...  

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the deterioration of articular cartilage. The progression of OA leads to an increase in inflammatory mediators in the joints, thereby promoting the destruction of the cartilage matrix. Recent studies have reported on the anti-inflammatory and antioxidant properties of cardamonin, which also appears to interact with cellular targets, such as nuclear erythroid 2-related factor 2 (Nrf2), extracellular signal-regulated kinase (ERK), and mammalian target of rapamycin (mTOR) during the progression of tumors. To date, few studies have investigated the effects of cardamonin on chondrocyte inflammation. In the current study, we determined that treating interleukin-1 beta (IL-1β-stimulated chondrocyte cells) with cardamonin significantly reduced the release of nitric oxide (NO) and prostaglandin E2 (PGE2) and significantly inhibited the expression of pro-inflammatory proteins, including inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). Cardamonin was also shown to: (1) inhibit the activation and production of matrix metalloproteinases (MMPs), (2) suppress the nuclear factor-κB (NF-κB) signaling pathway, (3) suppress the expression of toll-like receptor proteins, (4) activate the Nrf2 signaling pathway, and (5) increase the levels of antioxidant proteins heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). The increase in antioxidant proteins led to corresponding antioxidant effects (which were abolished by Nrf2 siRNA). Our findings identify cardamonin as a candidate Nrf2 activator for the treatment and prevention of OA related to inflammation and oxidative stress.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 599
Author(s):  
Yuesheng Dong ◽  
Yan Xing ◽  
Jin Sun ◽  
Wenlong Sun ◽  
Yongbin Xu ◽  
...  

Baicalein, a widely-distributed natural flavonoid, exhibits antioxidative activity in mice with type-2 diabetes. However, the underlying mechanisms remain partially elucidated. In this study, we investigated the effect of baicalein on protein kinase R-like ER kinase (PERK)/nuclear factor erythroid-2-related factor 2 (Nrf2) pathway for the alleviation of oxidative stress and apoptosis. Human liver HL-7702 cells were stimulated with 60.5 mM of glucose to induce oxidative stress and treated with baicalein. The apoptosis was determined by fluorescence microscopy and flow cytometry. The regulation of the PERK/Nrf2 pathway by baicalein was determined by immunoblotting in both HL-7702 cells and liver tissues from diabetic mice. We found that baicalein significantly alleviated the oxidative stress and apoptosis in HL-7702 cells stimulated with glucose. Mechanistic studies showed that baicalein downregulated PERK and upregulated Nrf2, two key proteins involved in endoplasmic reticulum stress, in both HL-7702 cells and liver tissues from diabetic mice receiving baicalein treatment. Furthermore, the subcellular localization of Nrf2 and the regulation of downstream proteins including heme oxygenase-1 and CCAAT-enhancer-binding protein homologous protein (CHOP) by baicalein were also investigated. Our results suggest that the regulation of the PERK/Nrf2 pathway is one of the mechanisms contributing to the bioactivities of baicalein to improve diabetes-associated complications.


2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Xiaotian Fu ◽  
Dongmei Chen ◽  
Yan Ma ◽  
Weifeng Yuan ◽  
Liqian Zhu

Bovine herpesvirus type 1 (BoHV-1) is a significant cofactor for bovine respiratory disease complex (BRDC), the most important inflammatory disease in cattle. BoHV-1 infection in cell cultures induces overproduction of pathogenic reactive oxygen species (ROS) and the depletion of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), a master transcriptional factor regulating a panel of antioxidant and cellular defense genes in response to oxidative stress. In this study, we reported that the virus productive infection in MDBK cells at the later stage significantly decreased the expression levels of heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase-1 (NQO1) proteins, the canonical downstream targets regulated by Nrf2, inhibited Nrf2 acetylation, reduced the accumulation of Nrf2 proteins in the nucleus, and relocalized nuclear Nrf2 proteins to form dot-like staining patterns in confocal microscope assay. The differential expression of Kelch-like ECH associated protein 1 (KEAP1) and DJ-1 proteins as well as the decreased association between KEAP1 and DJ-1 promoted Nrf2 degradation through the ubiquitin proteasome pathway. These data indicated that the BoHV-1 infection may significantly suppress the Nrf2 signaling pathway. Moreover, we found that there was an association between Nrf2 and LaminA/C, H3K9ac, and H3K18ac, and the binding ratios were altered following the virus infection. Taken together, for the first time, we provided evidence showing that BoHV-1 infection inhibited the Nrf2 signaling pathway by complicated mechanisms including promoting Nrf2 degradation, relocalization of nuclear Nrf2, and inhibition of Nrf2 acetylation.


Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 380 ◽  
Author(s):  
Huang ◽  
Chang ◽  
Chau ◽  
Chiu

Hispidin, a polyphenol compound isolated from Phellinus linteus, has been reported to possess antioxidant activities. In this study, we aimed to investigate the mechanisms underlying the protective effect of hispidin against hydrogen peroxide (H2O2)-induced oxidative stress on Adult Retinal Pigment Epithelial cell line-19 (ARPE-19) cells. Hispidin was not cytotoxic to ARPE-19 cells at concentrations of less than 50 μM. The levels of intracellular reactive oxygen species (ROS) were analyzed by dichlorofluorescin diacetate (DCFDA) staining. Hispidin significantly restored H2O2-induced cell death and reduced the levels of intracellular ROS. The expression levels of antioxidant enzymes, such as NAD(P)H:Quinine oxidoreductase-1 (NQO-1), heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and glutamate-cysteine ligase modifier subunit (GCLM) were examined using real-time PCR and Western blotting. Our results showed that hispidin markedly enhanced the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), HO-1, NQO-1, GCLM, and GCLC in a dose-dependent manner. Furthermore, knockdown experiments revealed that transfection with Nrf2 siRNA successfully suppresses the hispidin activated Nrf2 signaling in ARPE-19 cells. Moreover, activation of the c-Jun N-terminal kinase (JNK) pathway is involved in mediating the protective effects of hispidin on the ARPE-19 cells. Thus, the present study demonstrated that hispidin provides protection against H2O2-induced damage in ARPE-19 cells via activation of Nrf2 signaling and up-regulation of its downstream targets, including Phase II enzymes, which might be associated with the activation of the JNK pathway.


2014 ◽  
Vol 34 (2) ◽  
pp. 145-152 ◽  
Author(s):  
B Shen ◽  
W Wang ◽  
L Ding ◽  
Y Sao ◽  
Y Huang ◽  
...  

Aim: This study aimed to determine whether nuclear factor erythroid 2-related factor 2 antagonized the oxidative stress induced by di- N-butylphthalate (DBP) in testicular Leydig cells. Methods: Mouse TM3 testicular Leydig cells were treated with Nrf2 knockdown (KD) or overexpression in the presence and absence of DBP. Oxidative profiles were examined. Nrf2 target antioxidant genes were studied, and the effects of Nrf2 inducer sulphoraphane (SFN) were tested. Results: DBP induced intracellular oxidative stress to a similar extent with Nrf2 KD. Expression and protein levels of Nrf2 were increased together with its target genes, namely heme oxygenase 1, nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 and peroxiredoxin 6, following DBP stimulation. Use of SFN not only restored the intracellular oxidative toxicity but also cell proliferation and testosterone secretion in response to DBP. Conclusion: Increased Nrf2 activity, for example, by SFN can effectively antagonize the oxidative stress in testicular Leydig cells caused by DBP.


Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 116 ◽  
Author(s):  
Yuelian Li ◽  
Lu Liu ◽  
Peipei Sun ◽  
Yifeng Zhang ◽  
Tao Wu ◽  
...  

In recent years, microalgae have drawn increasing attention as a valuable source of functional food ingredients. Intriguingly, Nitzschia laevis is rich in fucoxanthinol that is seldom found in natural sources. Fucoxanthinol, a marine xanthophyll carotenoid, possesses various beneficial bioactivities. Nevertheless, it’s not clear whether fucoxanthinol could exert anti-neuroinflammatory function. In light of these premises, the aim of the present study was to investigate the anti-inflammatory role of fucoxanthinol purified from Nitzschia laevis in Lipopolysaccharide (LPS)-stimulated microglia. The results showed that pre-treatment of fucoxanthinol remarkably attenuated the expression of LPS-induced nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the production of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE-2), nitric oxide (NO) and reactive oxygen species (ROS) induction. Modulation mechanism studies revealed that fucoxanthinol hampered nuclear factor-kappa B (NF-κB), Akt, and mitogen-activated protein kinase (MAPK) pathways. Meanwhile, fucoxanthinol led to the enhancement of nuclear translocation of NF-E2-related factor 2 (Nrf2), and the upregulation of heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO-1). Taken together, the results indicated that fucoxanthinol obtained from Nitzschia laevis had great potential as a neuroprotective agent in neuroinflammation and neurodegenerative disorders.


2020 ◽  
Vol 15 (8) ◽  
pp. 1934578X2094723
Author(s):  
Pan Chen ◽  
Ziting Xiao ◽  
Hao Wu ◽  
Yonggang Wang ◽  
Weiwei Su ◽  
...  

Naringin possesses strong antioxidative activity and can protect against some respiratory diseases. Oxidative stress is thought to be a major factor in the development of many tobacco-caused diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays a critical role in the regulation of oxidative stress. The dynamic changes in the antioxidant system in the lung that are induced by cigarette smoke (CS) are not well investigated, and how naringin affects these changes remains unknown. This study aimed to investigate the dynamic changes between the oxidation and antioxidant systems resulting from CS exposure and the effects of naringin on these changes in mice. Mice were chronically exposed to CS for 30 days. The levels of malondialdehyde (MDA), glutathione (GSH), interleukin (IL)-6, and tumor necrosis factor-alpha (TNF-α); the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px); and the expressions of Nrf2, heme oxygenase-1 (HO-1), and nicotinamide adenine dinucleotide phosphate quinone dehydrogenase 1 (NQO1) in lung tissue were measured on days 2, 7, and 30. The levels of MDA, GSH, IL-6, and TNF-α in the lung were found to increase throughout the exposure. SOD and GSH-Px activities showed an increase on day 2 and a decrease on days 7 and 30. The messenger ribonucleic acid expressions of Nrf2, HO-1, and NQO1 were elevated on day 2 and decreased on day 7; Nrf2 and HO-1 expressions were continually decreased, but NQO1 expression was increased again, on day 30. Naringin restored the levels of these biochemical indices to normal throughout the experiment, suggesting that naringin protected against the CS-induced oxidative damage by suppressing the increase of antioxidants resulting from the early stage of CS exposure, as well as inhibiting the depletion of antioxidants due to long-term oxidative stress. Naringin also suppressed lung inflammation by inhibiting IL-6 and TNF-α. These results indicate that naringin possesses a powerful ability to maintain the balance of the oxidation/antioxidant system in the lung when subjected to CS exposure, probably by regulating the Nrf2 signaling pathway.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Golbarg Rahimi ◽  
Salime Heydari ◽  
Bahareh Rahimi ◽  
Navid Abedpoor ◽  
Iman Niktab ◽  
...  

Abstract Background SPTC is a mix of four herbal components (Salvia officinalis, Panax ginseng, Trigonella foenum-graeceum, and Cinnamomum zeylanicum) which might be prevented the development of AGE rich diet-induced diabetic complication and liver injury through activated the nuclear factor erythroid-2-related-factor-2 (Nrf2) pathway. Nrf2, as a master regulator of antioxidant response elements by activating cytoprotective genes expression, is decreased oxidative stress that associated with hyperglycemia and increases insulin sensitivity. the aim of this study was to assess whether the combination therapy of SPTC along with exercise or metformin moderate oxidative stress related liver injurie with more favorable effects in the treatment of AGE rich diet-induced type 2 diabetic mice. Methods We induced diabetes in C57BL/6 mice by AGE using a diet supplementation and limitation of physical activity. After 16 weeks of intervention, AGE fed mice were compared to control mice. Diabetic mice were assigned into seven experimental groups (each group; n = 5): diabetic mice, diabetic mice treated with SPTC (130 mg/kg), diabetic mice treated with Salvia Officinalis (65 mg/kg), diabetic mice treated with metformin (300 mg/kg), diabetic mice with endurance exercise training, diabetic mice treated with SPTC + metformin (130/300 mg/kg), diabetic mice treated with SPTC + exercise training. Results SPTC + exercise and SPTC + metformin reduced diabetic complications like gain weight, water and calorie intake, blood glucose, insulin, and GLUT4 content more efficiently than each treatment. These combinations improved oxidative stress hemostasis by activating the Nrf2 signaling pathway and attenuating keap1 protein more significantly. Conclusion Eventually, combined treatment of SPTC with exercise or metformin as a novel approach had more beneficial effects to prevent the development of diabetes and oxidative stress associated with hyperglycemia.


2021 ◽  
Vol 11 ◽  
Author(s):  
Jianjian Dong ◽  
Xiaoming Zhang ◽  
Shijing Wang ◽  
Chenchen Xu ◽  
Manli Gao ◽  
...  

Studies have indicated that oxidative stress plays a crucial role in the development of Parkinson’s disease (PD) and other neurodegenerative conditions. Research has also revealed that nuclear factor erythroid 2-related factor 2 (Nrf2) triggers the expression of antioxidant genes via a series of antioxidant response elements (AREs), thus preventing oxidative stress. Thymoquinone (TQ) is the bioactive component of Nigella sativa, a medicinal plant that exhibits antioxidant and neuroprotective effects. In the present study we examined whether TQ alleviates in vivo and in vitro neurodegeneration induced by 1-methyl-4-phenylpyridinium (MPP+) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) by acting as an activator of the Nrf2/ARE cascade. We showed that TQ significantly reduced MPP+-mediated cell death and apoptosis. Moreover, TQ significantly elevated the nuclear translocation of Nrf2 and significantly increased the subsequent expression of antioxidative genes such as Heme oxygenase 1 (HO-1), quinone oxidoreductase (NQO1) and Glutathione-S-Transferase (GST). The application of siRNA to silence Nrf2 led to an abolishment in the protective effects of TQ. We also found that the intraperitoneal injection of TQ into a rodent model of PD ameliorated oxidative stress and effectively mitigated nigrostriatal dopaminergic degeneration by activating the Nrf2-ARE pathway. However, these effects were inhibited by the injection of a lentivirus wrapped Nrf2 siRNA (siNrf2). Collectively, these findings suggest that TQ alleviates progressive dopaminergic neuropathology by activating the Nrf2/ARE signaling cascade and by attenuating oxidative stress, thus demonstrating that TQ is a potential novel drug candidate for the treatment of PD.


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