Commiphora molmol protects against methotrexate-induced nephrotoxicity by up-regulating Nrf2/ARE/HO-1 signaling
Commiphora molmol possesses multiple therapeutic benefits against various diseases; however, its protective role against methotrexate (MTX) renal toxicity has not been previously investigated. MTX is a dihydrofolate reductase inhibitor that can induce acute kidney injury (AKI). This study evaluated the in vitro antioxidant activity and the protective effect of C. molmol resin extract against MTX-induced oxidative stress, inflammation and renal injury. Male Wistar rats received 125 and 250 mg/kg C. molmol resin extract for 15 days and a single injection of MTX at day 16. C. molmol showed a radical scavenging activity against DPPH, superoxide and nitric oxide (NO) radicals. Rats received MTX showed renal injury evidenced by the significantly elevated serum creatinine and urea, and the histological alterations. The kidney of MTX-induced rats exhibited increased lipid peroxidation, NO, NF-κB and pro-inflammatory cytokines. Pre-treatment with C. molmol prevented MTX-induced kidney injury and attenuated oxidative stress and inflammation. C. molmol down-regulated Bax and enhanced the activity and expression of the antioxidant defenses. Furthermore, the expression of Bcl-2, Nrf2, NQO-1 and HO-1 was down-regulated in the kidney of MTX-induced rats. Pre-treatment with C. molmol resin up-regulated Bcl-2 and activated Nrf2/HO-1 signaling in the kidney of MTX-induced rats. In conclusion, C. molmol resin provided protection against MTX-induced AKI via activation of Nrf2 signaling and mitigation of oxidative stress.
Hydrogen peroxide modulates redox status, energy metabolism, and gene expression in a dose- and time-dependent manner in rat liver
The aim of this study was to investigate the effect of three different hydrogen peroxide (H O ) levels on blood and liver oxidative status, energy metabolites, and gene expression in male albino rats at two time intervals (2 and 4 weeks).
mTORC2 facilitates endothelial cell senescence by suppressing Nrf2 expression via the Akt/GSK-3β/C/EBPα signaling pathway
Vascular endothelial cell senescence is a leading cause of age-associated and vascular diseases. Mammalian target of rapamycin complex 2 (mTORC2) is a conserved serine/threonine (Ser/Thr) protein kinase that plays an important regulatory role in various cellular processes. However, its impact on endothelial senescence remains controversial. In this study we investigated the role and molecular mechanisms of mTORC2 in endothelial senescence. A replicative senescence model and HO-induced premature senescence model were established in primary cultured human umbilical vein endothelial cells (HUVECs). In these senescence models, the formation and activation of mTORC2 were significantly increased, evidenced by the increases in binding of Rictor (the essential component of mTORC2) to mTOR, phosphorylation of mTOR at Ser2481 and phosphorylation of Akt (the effector of mTORC2) at Ser473. Knockdown of Rictor or treatment with the Akt inhibitor MK-2206 attenuated senescence-associated β-galactosidase (β-gal) staining and expression of p53 and p21 proteins in the senescent endothelial cells, suggesting that mTORC2/Akt facilitates endothelial senescence. The effect of mTORC2/Akt on endothelial senescence was due to suppression of nuclear factor erythroid 2-related factor 2 (Nrf2) at the transcriptional level, since knockdown of Rictor reversed the reduction of Nrf2 mRNA expression in endothelial senescence. Furthermore, mTORC2 suppressed the expression of Nrf2 via the Akt/GSK-3β/C/EBPα signaling pathway. These results suggest that the mTORC2/Akt/GSK-3β/C/EBPα/Nrf2 signaling pathway is involved in both replicative and inducible endothelial senescence. The deleterious role of mTORC2 in endothelial cell senescence suggests therapeutic strategies (targeting mTORC2) for aging-associated diseases and vascular diseases.
Standardized Morinda citrifolia L. and Morinda elliptica L. leaf extracts alleviated fatigue by improving glycogen storage and lipid/carbohydrate metabolism
The antifatigue properties of Morinda elliptica (ME) leaf were compared with Morinda citrifolia (MC) leaf extracts. Sixty Balb/C mice were administered (N = 10): control water, standardized green tea extract (positive control 200 mg/kg body weight [BW]), either 200 or 400 mg MC/kg BW, or either 200 or 400 mg ME/kg BW). The mice performances, biochemical, and mRNA expressions were evaluated. After 6 weeks, the weight-loaded swimming time to exhaustion in the mice consuming 400 mg MC/kg, were almost five times longer than the control mice. The gene expressions analysis suggested the extracts enhanced performance by improving lipid catabolism, carbohydrate metabolism, electron transport, antioxidant responses, energy production, and tissue glycogen stores. The MC and ME extracts enhanced stamina by reducing blood lactate and blood urea nitrogen levels, increasing liver and muscle glycogen reserve through augmenting the glucose metabolism (glucose transporter type 4 and pyruvate dehydrogenase kinase 4), lipid catabolism (acyl-Coenzyme A dehydrogenases and fatty acid translocase), antioxidant (superoxide dismutase 2) defence responses, electron transport (COX4I2), and energy production (PGC1α, NRF1, NRF2, cytochrome C electron transport, mitochondrial transcription factor A, UCP1, and UCP3) biomarkers. The MC (containing scopoletin and epicatechin) was better than ME (containing only scopoletin) or green tea (containing epicatechin and GT catechins) for alleviating fatigue.
Targeting heme oxygenase-1 by quercetin ameliorates alcohol-induced acute liver injury via inhibiting NLRP3 inflammasome activation
Alcoholic hepatitis (AH) is characterized by inflammation and necrosis of liver tissue caused by excessive alcohol consumption and it even causes organ failure sometimes, in which oxidative stress plays an important role. Quercetin is a bioactive flavonoid in the class of polyphenols with a free-radical scavenging ability and anti-inflammatory activity. Recently it has aroused great interest because of its potential benefits in the prevention and intervention of cancer, cardiovascular abnormalities, neurodegenerative diseases, metabolic disorders and liver fibrosis. However, its role in alcoholic liver injury is still unclear and needs to be elucidated. Through database analysis and serum measurements, we found that there was a decline in the level of heme oxygenase-1 (HO-1) in patients with acute alcoholic hepatitis compared to healthy controls. Quercetin could elevate the expression of nuclear factor E2-related factor 2(Nrf2)/HO-1 and ameliorate ethanol-induced acute liver injury in rats. Moreover, this protective effect of quercetin could be diminished when combined with the HO-1 inhibitor ZnppIX which demonstrated a critical role of HO-1 in quercetin's hepatoprotection. The underlying mechanism of quercetin's benefit on the liver may be explained by its anti-oxidant properties and inhibitory effect on the ROS/NF-κB/NLRP3 inflammasome/IL-1β and IL-18 pathway by inducing HO-1. Meanwhile, quercetin also upregulated the anti-inflammatory factor IL-10, while it was found uncorrelated with HO-1 expression. In conclusion, quercetin can preserve the function of the liver in acute alcoholic injury by upregulating the expression of IL-10 and HO-1 and thus inhibiting NLRP3 inflammasome activation and inflammatory factor secretion. In other words, quercetin looks promising as an alternative treatment and HO-1 may be a potential target in the crosstalk of inflammation and oxidative stress in alcoholic liver damage.
Activation of the Nrf2-ARE Pathway Ameliorates Hyperglycemia-Mediated Mitochondrial Dysfunction in Podocytes Partly Through Sirt1
Previously we have shown that activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-antioxidant response element (ARE) attenuated hyperglycemia-induced damage in podocytes, but the molecular mechanism remains unknown.
N-Propargyl Caffeamide Skews Macrophages Towards a Resolving M2-Like Phenotype Against Myocardial Ischemic Injury via Activating Nrf2/HO-1 Pathway and Inhibiting NF-ĸB Pathway
Macrophages exhibit dynamic pro-inflammatory and resolving activities in myocardial infarction. The present study investigated whether caffeic acid derivatives could induce macrophage polarization towards a resolving M2 phenotype against myocardial infarction injury.
Aberrant regulation of the GSK-3β/NRF2 axis unveils a novel therapy for adrenoleukodystrophy
The nuclear factor erythroid 2-like 2 (NRF2) is the master regulator of endogenous antioxidant responses. Oxidative damage is a shared and early-appearing feature in X-linked adrenoleukodystrophy (X-ALD) patients and the mouse model ( null mouse). This rare neurometabolic disease is caused by the loss of function of the peroxisomal transporter ABCD1, leading to an accumulation of very long-chain fatty acids and the induction of reactive oxygen species of mitochondrial origin. Here, we identify an impaired NRF2 response caused by aberrant activity of GSK-3β. We find that GSK-3β inhibitors can significantly reactivate the blunted NRF2 response in patients' fibroblasts. In the mouse models ( and / mice), oral administration of dimethyl fumarate (DMF/BG12/Tecfidera), an NRF2 activator in use for multiple sclerosis, normalized (i) mitochondrial depletion, (ii) bioenergetic failure, (iii) oxidative damage, and (iv) inflammation, highlighting an intricate cross-talk governing energetic and redox homeostasis in X-ALD Importantly, DMF halted axonal degeneration and locomotor disability suggesting that therapies activating NRF2 hold therapeutic potential for X-ALD and other axonopathies with impaired GSK-3β/NRF2 axis.
Co-exposure to silver nanoparticles and cadmium induce metabolic adaptation in HepG2 cells
Although multiple studies have reported the toxicological effects and underlying mechanisms of toxicity of silver nanoparticles (AgNP) in a variety of organisms, the interactions of AgNP with environmental contaminants such as cadmium are poorly understood. We used biochemical assays and mass spectrometry-based proteomics to assess the cellular and molecular effects induced by a co-exposure of HepG2 cells to AgNP and cadmium. Cell viability and energy homeostasis were slightly affected after a 4-h exposure to AgNP, cadmium, or a combination of the two; these endpoints were substantially altered after a 24-h co-exposure to AgNP and cadmium, while exposure to one of the two contaminants led only to minor changes. Proteomics analysis followed the same trend: while a 4-h exposure induced minor protein deregulation, a 24-h exposure to a combination of AgNP and cadmium deregulated 43% of the proteome. The toxicity induced by a combined exposure to AgNP and cadmium involved (1) inactivation of Nrf2, resulting in downregulation of antioxidant defense and proteasome-related proteins, (2) metabolic adaptation and ADP/ATP imbalance, and (3) increased protein synthesis possibly to reestablish homeostasis. The adaptation strategy was not sufficient to restore ADP/ATP homeostasis and to avoid cell death.
Inhibition of the Nrf2/HO-1 Axis Suppresses the Mitochondria-Related Protection Promoted by Gastrodin in Human Neuroblastoma Cells Exposed to Paraquat
Mitochondria are double-membrane organelles involved in the transduction of energy from different metabolic substrates into adenosine triphosphate (ATP) in mammalian cells. The oxidative phosphorylation system is comprised by the activity of the respiratory chain and the complex V (ATP synthase/ATPase). This system is dependent on oxygen gas (O) in order to maintain a flux of electrons in the respiratory chain, since O is the final acceptor of these electrons. Electron leakage from this complex system leads to the continuous generation of reactive species in the cells. The mammalian cells exhibit certain mechanisms to attenuate the consequences originated from the constant exposure to these reactive species. In this context, the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and one of the enzymes whose expression is modulated by Nrf2, heme oxygenase-1 (HO-1), take a central role in inducing cytoprotection in humans. Mitochondrial abnormalities are observed during intoxication and in certain diseases, including neurodegeneration. Mitochondrial protection promoted by natural compounds has attracted the attention of researchers due to the promising effects these agents induce experimentally. In this regard, we examined here whether and how gastrodin (GAS), a phenolic glucoside, would prevent the paraquat (PQ)-induced mitochondrial impairment in the SH-SY5Y cells. The cells were exposed to GAS (25 μM) for 4 h prior to the challenge with PQ at 100 μM for additional 24 h. The silencing of Nrf2 by siRNA or the inhibition of HO-1 by ZnPP IX suppressed the GAS-elicited cytoprotection. Therefore, GAS promoted mitochondrial protection by an Nrf2/HO-1-dependent manner.
Curcumin Inhibits Lipopolysaccharide-Induced Mucin 5AC Hypersecretion and Airway Inflammation via Nuclear Factor Erythroid 2-Related Factor 2
Excess mucus production is an important pathophysiological feature of chronic inflammatory airway diseases. Effective therapies are currently lacking. The aim of the study was to evaluate the effects of curcumin (CUR) on lipopolysaccharide (LPS)-induced mucus secretion and inflammation, and explored the underlying mechanism in vivo and in vitro.
Vitamin E alleviates phoxim-induced toxic effects on intestinal oxidative stress, barrier function, and morphological changes in rats
Phoxim is an organic phosphorus pesticide that remains easily in the environment, such as human food and animal feed. The objective of this study was to explore the effect of vitamin E on phoxim-induced oxidative stress in the intestinal tissues of Sprague-Dawley (SD) rats. Forty-eight Sprague-Dawley rats were randomly assigned to a control group and three treatment groups: treatment group 1 (phoxim: 20 mg/kg·BW), treatment group 2 (phoxim: 180 mg/kg·BW), and treatment 3 (vitamin E + phoxim: 200 mg/kg·BW + 180 mg/kg·BW). Phoxim was given by gavage administration once a day for 28 days. The results showed that phoxim significantly reduced jejunum villus height in rats (P < 0.05), and decreased the mRNA expression of junction protein genes of rats, including Occlidin and Claudin-4 (P < 0.05). Phoxim reduced GSH content and T-AOC level in the intestinal mucosa (P < 0.05). The mRNA expression levels of oxidative stress-related genes (Nrf2 and GPx2) were decreased. The mRNA expression of SOD was significantly increased. In addition, phoxim increased the level of interleukin-6 (IL-6) in jejunum mucosa and significantly reduced the level of IL-8 in ileum mucosas, while significantly increased TNF-α secretion. The mRNA expression levels of IL-1β, IL-6, and IL-8 were significantly decreased, and mRNA expression of TNF-α was significantly increased (P < 0.05). Phoxim also increased the DNA expression of total cecal bacteria and Escherichia coli, inhibited the DNA expression of Lactobacillus and destroyed the intestinal barrier. Two hundred milligrams per kilogram BW vitamin E reduced the effect of phoxim on intestinal structure, alleviated the oxidative stress in intestinal tissue, and decreased the level of TNF-α. The mRNA expressions of antioxidative stress genes (SOD and GPx2) were significantly increased. The DNA expression level of Lactobacillus was significantly increased. In conclusion, vitamin E helped reduce the toxicity of organophosphate pesticides, such as phoxim on rat intestinal tissue.
MicroRNA-135b-5p prevents oxygen-glucose deprivation and reoxygenation-induced neuronal injury through regulation of the GSK-3β/Nrf2/ARE signaling pathway
MicroRNAs (miRNAs) are emerging as critical regulators in the pathological process of cerebral ischemia/reperfusion injury. miRNAs play an important role in regulating neuronal survival. miR-135b-5p has been reported as an important miRNA in regulating cell apoptosis. However, the role of miR-135b-5p in regulating neuronal survival remains poorly understood. Here, we aimed to investigate the role of miR-135b-5p in cerebral ischemia/ reperfusion using an model of oxygen-glucose deprivation and reoxygenation-(OGD/R) induced neuron injury.
Caenorhabditis elegans respond to high-glucose diets through a network of stress-responsive transcription factors
High-glycemic-index diets, as well as a sedentary lifestyle are considered as determinant factors for the development of obesity, type 2 diabetes, and cardiovascular diseases in humans. These diets have been shown to shorten the life span of C. elegans in a manner that is dependent on insulin signaling, but the participation of other signaling pathways have not been addressed. In this study, we have determined that worms fed with high-glucose diets show alterations in glucose content and uptake, triglyceride content, body size, number of eggs laid, egg-laying defects, and signs of oxidative stress and accelerated aging. Additionally, we analyzed the participation of different key regulators of carbohydrate and lipid metabolism, oxidative stress and longevity such as SKN-1/NRF2, HIF-1/HIF1α, SBP-1/SREBP, CRH-1/CREB, CEP-1/p53, and DAF-16/FOXO, in the reduction of lifespan in glucose-fed worms.
2'--Galloylhyperin Isolated From Fisch. Attenuates LPS-Induced Inflammatory Response by Activation of SIRT1/Nrf2 and Inhibition of the NF-κB Pathways and
2'--galloylhyperin, a major compound of Fisch., possesses a variety of biological and pharmacological activities, including anti-oxidative and anti-inflammatory activities. Nevertheless, the underlying molecular mechanisms of 2-GH in microbial infection and sepsis are not clear. In this study, we investigated the anti-inflammatory effects of 2-GH. We found that 2-GH significantly reduced the production of TNF-α, IL-6, and nitric oxide (NO), suppressed the expression levels of iNOS, blocked the translocation of NF-κB from the cytosol to nucleus, and decreased the MAPK activation in LPS-activated RAW 264.7 cells. 2-GH also enhanced the nuclear translocation of Nrf2 and up-regulated the expression of heme oxygenase-1 (HO-1) and SIRT1. In addition, the administration of 2-GH attenuated the TNF-α and IL-6 production in the serum, infiltration of inflammatory cells, liver tissue damage, and the mortality rate of LPS-challenged mice. Moreover, 2-GH significantly upregulated Nrf2 and SIRT1 expression and inhibited the inflammatory responses in the liver of septic mice. The collective data indicate that 2-GH could potentially be a novel functional food candidate in the treatment of sepsis.