scholarly journals The Role of Nrf2 Signaling Pathway in Eucommia ulmoides Flavones Regulating Oxidative Stress in the Intestine of Piglets

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Dingfu Xiao ◽  
Daixiu Yuan ◽  
Bihui Tan ◽  
Jing Wang ◽  
Yanhong Liu ◽  
...  

Eucommia ulmoides flavones (EUF) have been demonstrated to alleviate oxidative stress and intestinal damage in piglets, but their effect target is still poorly understood. NF-E2-related factor 2 (Nrf2) pathway plays a very important role in the defense mechanism. This study was designed to investigate the regulation of EUF on the Nrf2 pathway and inhibition of Nrf2 on oxidative stress in the intestine of piglets. An in vivo study was conducted in weaned piglets treated with basal diet, basal diet+diquat, and 100 mg/kg EUF diet+diquat for 14 d to determine Nrf2 and Keap1 protein expressions, as well as downstream antioxidant gene mRNA expression. An in vitro study was performed in a porcine jejunal epithelial cell line to investigate the effect of inhibiting Nrf2 on cell growth and intracellular oxidative stress parameters. The results showed that the supplementation of EUF decreased the oxidized glutathione (GSSG) concentration and the ratio of GSSG to glutathione (GSH) but increased the protein expressions of nuclear Nrf2 and Kelch-like ECH-associated protein 1 (Keap1) as well as mRNA expression of heme oxygenase 1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1), and glutamate cysteine ligase catalytic subunit (GCLC) in the small intestinal mucosa of diquat-challenged piglets. When Nrf2 was inhibited by using ML385, cell viability, cellular antioxidant activities, expressions of nuclear Nrf2 and Keap1 protein, and downstream antioxidant enzyme (HO-1, NQO-1, and GCLC) mRNA were decreased in paraquat-treated enterocytes. These results showed that the Nrf2 signaling pathway played an important role in EUF-regulating oxidative stress in the intestine of piglets.

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1053 ◽  
Author(s):  
Lei Sun ◽  
Gaoqing Xu ◽  
Yangyunyi Dong ◽  
Meng Li ◽  
Lianyu Yang ◽  
...  

We investigated the potential ability of quercetin to protect against lipopolysaccharide (LPS)-induced intestinal oxidative stress in broiler chickens and the potential role of the Nrf2 (nuclear factor erythroid 2-related factor 2) signaling pathway. One-day-old broiler chickens (n = 240) were randomized into four groups: saline-challenged broiler chickens fed a basal diet (Con), LPS-challenged broiler chickens on a basal diet (LPS), and LPS-treated broiler chickens on a basal diet containing either 200 or 500 mg/kg of quercetin (Que200+LPS or Que500+LPS). Quercetin (200 mg/kg) significantly alleviated LPS-induced decreased duodenal, jejunal, and illeal villus height and increased the crypt depth in these regions. Quercetin significantly inhibited LPS-induced jejunal oxidative stress, including downregulated reactive oxygen species (ROS), malondialdehyde (MDA), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels, and it upregulated superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels. Quercetin relieved LPS-induced jejunal mitochondria damage and upregulated mitochondrial DNA copy number-related gene expression, including cytochrome c oxidase subunit 1 (COX1), ATP synthase F0 subunit 6 (ATP6), and NADH dehydrogenase subunit 1 (ND1). Quercetin attenuated the LPS-induced inhibition of Nrf2 activation, translocation, and downstream gene expression, including heme oxygenase-1 (HO-1), NAD (P) H dehydrogenase quinone 1 (NQO1), and manganese superoxide dismutase (SOD2). Additionally, quercetin attenuated the LPS-inhibition of c-Jun N-terminal kinase (JNK), Extracellular Regulated protein Kinases (ERK), and p38MAPK (p38) phosphorylation in the MAPK pathway. Thus, quercetin attenuated LPS-induced oxidative stress in the intestines of broiler chickens via the MAPK/Nrf2 signaling pathway.


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.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Zhenli Yuan ◽  
Weiwei Du ◽  
Xiangdong He ◽  
Donglei Zhang ◽  
Wei He

Oxidative stress on retinal pigment epithelial (RPE) cells has been confirmed to play a crucial role in the development and progression of age-related macular degeneration (AMD) or other retinal degenerative diseases. Tribulus terrestris (TT) is a Chinese traditional herb medicine, which has been used for the treatment of ocular diseases for many centuries. In this study, we investigated the underlying mechanisms of TT and examined its ability to protect and restore the human retinal pigment epithelial cells (ARPE-19) against H2O2-induced oxidative stress. Our data show that 200 μg/mL of ethanol extract of Tribulus terrestris (EE-TT) significantly increased the cell viability and prevented the apoptosis of H2O2-treated ARPE-19 cells through the regulation of Bcl2, Bax, cleaved caspase-3, and caspase-9. Treatment with EE-TT also significantly decreased the upregulated reactive oxygen species (ROS) activities and increased the downregulated superoxide dismutase (SOD) activities induced by H2O2 in ARPE-19 cells. Additionally, H2O2 at 1 mM significantly decreased the mRNA expression levels of Nrf2, CAT, SOD1, SOD2, HO-1, GST-pi, NQO1, and GLCM in ARPE-19 cells; however, treatment with EE-TT reversed the downregulated mRNA expression levels of all these genes induced by H2O2. Furthermore, treatment with 200 μg/mL EE-TT alone for 24 h significantly increased Nrf2, HO-1, NQO1, and GCLM mRNA expressions in ARPE-19 cells when compared with untreated control cells. Pretreatment with the inhibitor of PI3K/Akt signaling (LY294002) completely blocked these EE-TT-upregulated mRNA expressions and abolished the improvement of cell viability in H2O2-treated ARPE-19 cells. These findings all suggest that Tribulus terrestris has significant antioxidant effects on oxidative stressed ARPE-19 cells through regulating PI3K/Akt-Nrf2 signaling pathway.


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.


Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 496 ◽  
Author(s):  
Yawang Sun ◽  
Yongjiang Wu ◽  
Zili Wang ◽  
Juncai Chen ◽  
You Yang ◽  
...  

In practical dairy production, cows are frequently subjected to inflammatory diseases, such as high-grain diet-induced subacute ruminal acidosis (SARA) as well as mastitis and metritis. Under the circumstances, lipopolysaccharide (LPS) induces oxidative stress within the cow and in the mammary epithelial cells. It has implications in practical production to alleviate oxidative stress and to optimize the lactational function of the mammary epithelial cells. This study thus aimed to investigate the antioxidative effects of dandelion aqueous extract (DAE) on LPS-induced oxidative stress and the mechanism of DAE as an antioxidant to alleviate oxidative stress through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in the bovine mammary epithelial cell line MAC-T cells. The cells were cultured for 48 h in six treatments including control (without LPS and DAE), LPS (100 ng/mL), DAE10 (100 ng/mL LPS and 10 μg/mL DAE), DAE50 (100 ng/mL LPS and 50 μg/mL DAE), DAE100 (100 ng/mL LPS and 100 μg/mL DAE), and DAE200 (100 ng/mL LPS and 200 μg/mL DAE), respectively. The results showed that cell viability was reduced by LPS, and the adverse effect of LPS was suppressed with the supplementation of DAE. Lipopolysaccharide-induced oxidative stress through enhancing reactive oxygen species (ROS) production, resulted in increases in oxidative damage marker concentrations, while 10 and 50 μg/mL DAE alleviated the LPS-induced oxidative stress via scavenging cellular ROS and improving antioxidant enzyme activity. The upregulation of antioxidative gene expression in DAE treatments was promoted through activating the Nrf2 signaling pathway, with DAE at a concentration of 50 μg/mL exhibiting the highest effect. Overall, DAE acted as an effective antioxidant to inhibit LPS-induced oxidative stress and as a potential inducer of the Nrf2 signaling pathway.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Hui Pan ◽  
Wenjing Feng ◽  
Ming Chen ◽  
Hong Luan ◽  
Yi Hu ◽  
...  

Aging is an independent risk factor for the development of age-related progressive kidney injury. As a part of the aging process, kidney aging has been indicated to be associated with oxidative stress-induced damage. Ameliorating oxidative damage is therefore considered a promising strategy for delaying kidney aging. Alginate oligosaccharide (AOS) has been reported to have a wide range of biological and pharmacological activities. However, no studies have focused on the role of AOS in delaying the kidney aging process. In this study, we aimed to evaluate the potential effects of AOS on kidney aging and its possible mechanisms. Subcutaneous injection of D-galactose (D-gal) (200 mg·kg-1·d-1) in C57BL/6J mice for 8 weeks was used to establish the aging model. AOS (200 mg·kg-1·d-1) was administered via oral gavage for the last four weeks. As a result, AOS inhibited the D-gal-induced upregulation of aging markers and significantly improved the kidney index and kidney function of D-gal-induced mice. In addition, AOS ameliorated the degree of tissue damage and fibrosis in the aging kidney. To further explore the potential mechanisms by which AOS attenuates the kidney aging process, the associated oxidative stress-induced damage was analyzed in depth. The data showed that AOS upregulated the expression of Klotho and decreased malondialdehyde levels by increasing the expression of antioxidant enzymes. Furthermore, our results suggested that AOS activated the nuclear factor erythrogen-2 associated factor 2 (Nrf2) pathway by promoting Nrf2 nuclear translocation in aging mice and upregulated the downstream expression of heme oxygenase-1 (HO-1) and NADPH quinone oxidoreductase 1 (NQO1). In conclusion, the present study demonstrated that AOS is a promising agent for attenuating kidney aging, and the underlying molecular mechanisms are related to the activation of the Nrf2 signaling pathway.


2020 ◽  
pp. 074823372097942
Author(s):  
Guangtao Yang ◽  
Yingping Xiang ◽  
Wei Zhou ◽  
Xiaohuan Zhong ◽  
Yanfang Zhang ◽  
...  

The bromoalkane, 1-bromopropane (1-BP), may damage the reproductive system though oxidative stress, while the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in regulating intracellular antioxidant levels against oxidative stress. This study explored the role of oxidative stress and the Nrf2 signaling pathway in mediating the reproductive toxicity of 1-BP using the ovarian carcinoma cell line OVCAR-3 as an in vitro model of the human ovary. OVCAR-3 cells were treated with 1, 5, 10 and 15 mM 1-BP. After 24 h, the cellular reactive oxygen species and malondialdehyde concentrations significantly increased, while the superoxide dismutase activity decreased; translocation of Nrf2 from the cytosol to the nucleus as well as downstream protein expression of Nrf2-regulated genes heme oxygenase-1 and Bcl-2 was inhibited. Apoptosis was also observed, accompanied by increased caspase-3 and caspase-9 activity. The antioxidant vitamin C alleviated 1-BP-induced apoptosis by inhibiting caspase activity activating the Nrf2 signaling pathway. These findings suggested that 1-BP induced oxidative stress and apoptosis in OVCAR-3 cells through inactivation of Nrf2 signaling.


Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1144
Author(s):  
Yongwei Zhao ◽  
Yu Niu ◽  
Jintian He ◽  
Lili Zhang ◽  
Chao Wang ◽  
...  

The object of present study was to evaluate the effects of dihydroartemisinin (DHA) supplementation on the hepatic antioxidant capacity in IUGR-affected weaned piglets. Eight piglets with normal birth weight (NBW) and sixteen IUGR-affected piglets were selected. Piglets were weaned at 21 days. NBW and IUGR groups were fed a basal diet and the ID group was fed the basal diet supplemented with 80 mg/kg DHA for 28 days. The result indicated that compared with NBW piglets, IUGR-affected piglets increased (p < 0.05) the concentration of malondialdehyde (MDA) and decreased (p < 0.05) the serum activities of total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). In addition, IUGR-affected piglets showed increased (p < 0.05) hepatic concentrations of protein carbonyl (PC), 8-hydroxy-2’-deoxyguanosine (8-OHdG), and oxidized glutathione (GSSG), and an increased GSSG:GSH value. IUGR-affected piglets exhibited lower (p < 0.05) activities of GSH-Px, T-SOD, total antioxidant capacity (T-AOC), and the concentration of glutathione (GSH). DHA supplementation decreased (p < 0.05) the serum concentration of MDA and increased the serum activities of T-AOC, T-SOD, GSH-Px, and CAT. The ID group showed decreased (p < 0.05) concentrations of MDA, PC, 8-OHdG, and GSSG, and a decreased GSSG:GSH value in the liver. The hepatic activity of T-SOD and the concentration of GSH were increased (p < 0.05) in the liver of ID group. IUGR-affected piglets downregulated (p < 0.05) mRNA expression of nuclear erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and CAT. DHA supplementation increased (p < 0.05) mRNA expression of Nrf2, HO-1, GPx1, and CAT in the ID group. In addition, the protein expression of Nrf2 was downregulated (p < 0.05) in the liver of IUGR-affected piglets and DHA supplementation increased (p < 0.05) the protein content of Nrf2 and HO-1. In conclusion, DHA may be beneficial in alleviating oxidative damage induced by IUGR through the Nrf2/ARE signaling pathway in the liver.


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.


Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3874
Author(s):  
Kristin Wächter ◽  
Alexander Navarrete Santos ◽  
Anne Großkopf ◽  
Tim Baldensperger ◽  
Marcus A. Glomb ◽  
...  

Advanced glycation end products (AGEs) result from a non-enzymatic reaction of proteins with reactive carbohydrates. Heat-processed food, such as bread, contains high amounts of AGEs. The activation of the NF-κB signaling pathway by bread crust extract (BCE) is well understood. However, it is largely unknown whether NRF2, the master regulator of oxidative stress resistance in mammalian cells, is affected by BCE. We have investigated the molecular mechanisms by which BCE induces antioxidant gene expression in cellular models. Our data showed that soluble extracts from bread crust are capable of stimulating the NRF2 signaling pathway. Furthermore, NRF2 pathway activation was confirmed by microarray and reporter-cell analyses. QRT-PCR measurements and Western blot analyses indicated an induction of antioxidative genes such as HMOX1, GCLM and NQO1 upon BCE treatment. Moreover, BCE pretreated cells had a survival advantage compared to control cells when exposed to oxidative stress. BCE induces phosphorylation of AKT and ERK kinase in EA.hy926 cells. By mass spectrometry, several new, potentially active modifications in BCE were identified. Our findings indicate that BCE activates NRF2-dependent antioxidant gene expression, thus provoking a protection mechanism against oxidative stress-mediated tissue injury. Hence, BCE can be considered as functional food with antioxidative and cardioprotective potential.


Sign in / Sign up

Export Citation Format

Share Document