S-adenosyl methionine protects ob/ob mice from CYP2E1-mediated liver injury

2007 ◽  
Vol 293 (1) ◽  
pp. G91-G103 ◽  
Author(s):  
Aparajita Dey ◽  
Andres A. Caro ◽  
Arthur I. Cederbaum

Pyrazole treatment to induce cytochrome P-450 2E1 (CYP2E1) was recently shown to cause liver injury in ob/ob mice but not in lean mice. The present study investigated the effects of S-adenosyl-l-methionine (SAM) on the CYP2E1-dependent liver injury in ob/ob mice. Pyrazole treatment of ob/ob mice for 2 days caused necrosis, steatosis, and elevated serum transaminase and triglyceride levels compared with saline ob/ob mice. Administration of SAM (50 mg/kg body wt ip every 12 h for 3 days) prevented the observed pathological changes as well as the increase of apoptotic hepatocytes, caspase 3 activity, and serum TNF-α levels. SAM administration inhibited CYP2E1 activity but not CYP2E1 content. The pyrazole treatment increased lipid peroxidation, 4-hydroxynonenal and 3-nitrotyrosine protein adducts, and protein carbonyls. These increases in oxidative and nitrosative stress were prevented by SAM. Treatment of ob/ob mice with pyrazole lowered the endogenous SAM levels, and these were elevated after SAM administration. Mitochondrial GSH levels were very low after pyrazole treatment of the ob/ob mice; this was associated with elevated levels of malondialdehyde and 4-hydroxynonenal and 3-nitrotyrosine protein adducts in the mitochondria. All these changes were prevented with SAM administration. SAM protected against pyrazole-induced increase in serum transaminases, necrosis, triglyceride levels, caspase-3 activity, and lipid peroxidation even when administered 1 day after pyrazole treatment. In the absence of pyrazole, SAM lowered the slightly elevated serum transaminases, triglyceride levels, caspase-3 activity, and lipid peroxidation in obese mice. In conclusion, SAM protects against and can also reverse or correct CYP2E1-induced liver damage in ob/ob mice.

2001 ◽  
Vol 281 (5) ◽  
pp. F948-F957 ◽  
Author(s):  
Eisei Noiri ◽  
Akihide Nakao ◽  
Koji Uchida ◽  
Hirokazu Tsukahara ◽  
Minoru Ohno ◽  
...  

First Published July 12, 2001; 10.1152/ajprenal.0071.2001.—Generation of reactive oxygen species and nitric oxide in hypoxia-reperfusion injury may form a cytotoxic metabolite, peroxynitrite, which is capable of causing lipid peroxidation and DNA damage. This study was designed to examine the contribution of oxidative and nitrosative stress to the renal damage in ischemic acute renal failure (iARF). iARF was initiated in rats by 45-min renal artery clamping. This resulted in lipid peroxidation, DNA damage, and nitrotyrosine modification confirmed both by Western and immunohistochemical analyses. Three groups of animals were randomly treated with an inhibitor of inducible nitric oxide synthase (NOS),l- N 6-(1-iminoethyl)lysine (l-Nil), cell-permeable lecithinized superoxide dismutase (SOD), or both. Each treatment resulted in amelioration of renal dysfunction, as well as reduced nitrotyrosine formation, lipid peroxidation, and DNA damage, thus suggesting that peroxynitrite rather than superoxide anion is responsible for lipid peroxidation and DNA damage. Therefore, in a separate series of experiments, a scavenger of peroxynitrite, ebselen, was administered before the reperfusion period. This treatment resulted in a comparable degree of amelioration of iARF. In conclusion, the present study provides the first attempt to elucidate the role of peroxynitrite in initiation of the cascade of lipid peroxidation and DNA damage to ischemic kidneys. The results demonstrate that l-Nil , lecithinized SOD, and ebselen treatments improve renal function due to their suppression of peroxynitrite production or its scavenging, consequently preventing lipid peroxidation and oxidative DNA damage.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Carmen De Miguel ◽  
William C Hamrick ◽  
Laureano Asico ◽  
Pedro Jose ◽  
Santiago Cuevas

DJ-1 -/- mice, relative to wild-type (WT) littermates, have increased blood pressure (BP) ( DJ-1 -/- :130±4 vs WT:100±3 mmHg, n=6/8). and renal expressions of nitro-tyrosine (+76±31% of WT mice, n=5) and malondialdenyde (+63±23% of WT mice, n=4). Tempol, a superoxide dismutase mimetic, decreased the BP of DJ-1 -/- mice ( DJ-1 -/- : before tempol:119±3; after tempol:100±1 mmHg vs WT, n=4) and renal malondialdehyde production ( DJ-1 -/- : before tempol:+40±5%; after tempol:-24±5% vs WT, n=4) but increased serum nitrate/nitrite levels (+72±30%, n=4), indicating the presence of both oxidative and nitrosative stress. Lack of DJ-1 makes some cells vulnerable to endoplasmic reticulum (ER) stress. However, renal mRNA expression of ER stress markers, GRP94, ATF-4, ATF-6, sXBP-1, CHOP, caspase-12, and caspase-3 was not different between DJ-1 -/- and WT (n=7) mice. Markers of inflammation, IL-6, TNF α, MCP-1, NFκB, and T-cell and macrophage infiltration, were also not increased in the kidney of DJ-1 -/- mice. By contrast, renal mitochondrial (mt) HSP60, but not mtHSP40, was increased in DJ-1 -/- mice (2.9±0.1 fold, n=4) but there were no changes in the renal mRNA expressions of Nix/BNIP3L, BNIP3, PINK, FIS1, MFN1, MFN2, PPRC1, NRF-1, and PGC1, indicating that mt oxidative stress did not affect mt function. The renal expression of UCP2, which is involved in the control of mt-reactive oxygen species production, was elevated in DJ-1 -/- mice (4.1±1.1 fold of WT, n=4). Silencing UCP2 in mouse renal proximal tubule cells (-0.46.5±0.01 fold) increased the expression of ER stress and apoptosis markers CHOP (2±0.4 fold), ATF4 (2.6±0.6 fold), caspase-3 (2.3±0.4 fold), and caspase-12 (1.7±0.2 fold)(n=3). There were no differences in renal renin expression, sodium excretion, and serum creatinine between DJ-1 -/- and WT mice (n=5). There were no abnormalities in renal morphology, including fibrosis, in the kidneys of DJ-1 -/- mice. However, urinary KIM-1 was increased in DJ-1 -/- mice (148±22% of WT mice, n=4) and decreased by tempol (-58±3%, n=4); renal UCP2 expression was also partially normalized by tempol (1.8±0.2 fold of WT, n=4). UCP2 may protect from the development of renal ER stress and damage in the mt oxidative/nitrosative stress associated with DJ-1 depletion.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Bartosz Proniewski ◽  
Agnieszka Kij ◽  
Barbara Sitek ◽  
Eric E. Kelley ◽  
Stefan Chlopicki

Detection of free radicals in tissues is challenging. Most approaches rely on incubating excised sections or homogenates with reagents, typically at supraphysiologic oxygen tensions, to finally detect surrogate, nonspecific end products. In the present work, we explored the potential of using intravenously (i.v.) injected dihydroethidine (DHE) to detect superoxide radical (O2∙-) abundancein vivoby quantification of the superoxide-specific DHE oxidation product, 2-hydroxyethidium (2-OH-E+), as well as ethidium (E+) and DHE in multiple tissues in a murine model of endotoxemia induced by lipopolysaccharide (LPS). LPS was injected intraperitoneally (i.p.), while DHE was delivered via the tail vein one hour before sacrifice. Tissues (kidney, lung, liver, and brain) were harvested and subjected to HPLC/fluorescent analysis of DHE and its monomeric oxidation products. In parallel, electron spin resonance (EPR) spin trapping was used to measure nitric oxide (∙NO) production in the aorta, lung, and liver isolated from the same mice. Endotoxemic inflammation was validated by analysis of plasma biomarkers. The concentration of 2-OH-E+varied in the liver, lung, and kidney; however, the ratios of 2-OH-E+/E+and 2-OH-E+/DHE were increased in the liver and kidney but not in the lung or the brain. An LPS-induced robust level of∙NO burst was observed in the liver, whereas the lung demonstrated a moderate yet progressive increase in the rate of∙NO production. Interestingly, endothelial dysfunction was observed in the aorta, as evidenced by decreased∙NO production 6 hours post-LPS injection that coincided with the inflammatory burden of endotoxemia (e.g. elevated serum amyloid A and prostaglandin E2). Combined, these data demonstrate that systemic delivery of DHE affords the capacity to specifically detect O2∙-productionin vivo. Furthermore, the ratio of 2-OH-E+/E+oxidation products in tissues provides a tool for comparative insight into the oxidative environments in various organs. Based on our findings, we demonstrate that the endotoxemic liver is susceptible to both O2∙--mediated and nonspecific oxidant stress as well as nitrosative stress. Oxidant stress in the lung was detected to a lesser extent, thus underscoring a differential response of liver and lung to endotoxemic injury induced by intraperitoneal LPS injection.


Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 582
Author(s):  
Ahlam Alhusaini ◽  
Laila Fadda ◽  
Iman H. Hasan ◽  
Hanaa M. Ali ◽  
Naglaa F. El Orabi ◽  
...  

Arctium lappa L. (A. lappa) is a popular medicinal plant with promising hepatoprotective activity. This study investigated the protective effect of A. lappa root extract (ALRE) on lead (Pb) hepatotoxicity, pointing to its ability to modulate oxidative stress, inflammation, and protein kinase B/Akt/glycogen synthase kinase (GSK)-3β signaling. Rats received 50 mg/kg lead acetate (Pb(Ac)2) and 200 mg/kg ALRE or vitamin C (Vit. C) for 7 days, and blood and liver samples were collected. Pb(Ac)2 provoked hepatotoxicity manifested by elevated serum transaminases and lactate dehydrogenase, and decreased total protein. Histopathological alterations, including distorted lobular hepatic architecture, microsteatotic changes, congestion, and massive necrosis were observed in Pb(II)-induced rats. ALRE ameliorated liver function and prevented all histological alterations. Pb(II) increased hepatic lipid peroxidation (LPO), nitric oxide (NO), caspase-3, and DNA fragmentation, and serum C-reactive protein, tumor necrosis factor-α, and interleukin-1β. Cellular antioxidants, and Akt and GSK-3β phosphorylation levels were decreased in the liver of Pb(II)-induced rats. ALRE ameliorated LPO, NO, caspase-3, DNA fragmentation and inflammatory mediators, and boosted antioxidant defenses in Pb(II)-induced rats. In addition, ALRE activated Akt and inhibited GSK-3β in the liver of Pb(II)-induced rats. In conclusion, ALRE inhibits liver injury in Pb(II)-intoxicated rats by attenuating oxidative injury and inflammation, and activation of Akt/GSK-3β signaling pathway.


Antioxidants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 446 ◽  
Author(s):  
Islam ◽  
Yu ◽  
Miao ◽  
Liu ◽  
He ◽  
...  

The root bark of Illicium henryi has been used in traditional Chinese medicine to treat lumbar muscle strain and rheumatic pain. Its ethanol extract (EEIH) has been previously reported to attenuate lipopolysaccharide (LPS)-induced acute kidney injury in mice. The present study aimed to evaluate the in vitro antioxidant activities and in vivo protective effects of EEIH against LPS-induced acute liver injury (ALI) in mice as well as explore its molecular mechanisms. The mice were injected intraperitoneally (i.p.) with EEIH at the doses of 1.25, 2.5, and 5.0 mg/kg every day for 5 days. One hour after the last administration, the mice were administered i.p. with LPS (8 mg/kg). After fasting for 12 h, blood and liver tissues were collected to histopathological observation, biochemical assay, enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot analyses. EEIH possessed 2,2-diphenyl-1-picrylhydrazil (DPPH) and 2,2′-azino-bis-(3-ethylbenzothiozoline-6-sulfonic acid) disodium salt (ABTS) radical scavenging activities and ferric-reducing antioxidant capacity in vitro. The histopathological examination, serum biochemical analysis, and liver myeloperoxidase (MPO) activity showed that EEIH pretreatment alleviated LPS-induced liver injury in mice. EEIH significantly dose-dependently decreased the mRNA and protein expression levels of inflammatory factors TNF-α, IL-1β, IL-6, and COX-2 in liver tissue of LPS-induced ALI mice via downregulating the mRNA and protein expressions of toll-like receptor 4 (TLR4) and inhibiting the phosphorylation of nuclear factor-κB (NF-κB) p65. Furthermore, EEIH markedly ameliorated liver oxidative and nitrosative stress burden in LPS-treated mice through reducing the content of thiobarbituric acid reactive substances (TBARS), inducible nitric oxide synthase (iNOS), and nitric oxide (NO) levels, restoring the decreased superoxide dismutase (SOD) and reduced glutathione (GSH) levels, and up-regulating nuclear factor erythroid 2 related factor 2 (Nrf2). These results demonstrate that EEIH has protective effects against ALI in mice via alleviating inflammatory response, oxidative and nitrosative stress burden through activating the Nrf2 and suppressing the TLR4/NF-κB signaling pathways. The hepatoprotective activity of EEIH might be attributed to the flavonoid compounds such as catechin (1), 3′,4′,7-trihydroxyflavone (2), and taxifolin (7) that most possibly act synergistically.


2005 ◽  
Vol 289 (2) ◽  
pp. G308-G319 ◽  
Author(s):  
Yongke Lu ◽  
Xiaodong Wang ◽  
Arthur I. Cederbaum

Elevated LPS and elevated cytochrome P-450 2E1 (CYP2E1) in liver are two major independent risk factors in alcoholic liver disease. We investigated possible synergistic effects of the two risk factors in causing oxidative stress and liver injury. Sprague-Dawley rats were injected intraperitoneally with pyrazole (inducer of CYP2E1) for 2 days, and then LPS was injected via tail vein. Other rats were treated with pyrazole alone or LPS alone or saline. Eight hours later, blood was collected and livers were excised. Pathological evaluation showed severe inflammatory responses and necroses only in liver sections from rats in the pyrazole plus LPS group; blood transaminase levels were significantly elevated only in the combination group. Activities of caspase-3 and -9 and positive terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining were highest in the LPS alone and the LPS plus pyrazole group, with no significant difference between the two groups. Lipid peroxidation and protein carbonyls in liver homogenate as well as in situ superoxide production were maximally elevated in the LPS plus pyrazole group. Levels of nitrite plus nitrate and inducible nitric oxide (NO) synthase (iNOS) content were comparably elevated in LPS alone and the LPS plus pyrazole group; however, 3-nitrotyrosine adducts were elevated in the combined group but not the LPS group. It is likely that LPS induction of iNOS, which produces NO, coupled to pyrazole induction of CYP2E1 which produces superoxide, sets up conditions for maximal peroxynitrite formation and production of 3-nitrotyrosine adducts. CYP2E1 activity and content were elevated in the pyrazole and the LPS plus pyrazole groups. Immunohistochemical staining indicated that distribution of CYP2E1 was in agreement with that of necrosis and production of superoxide. These results show that pyrazole treatment enhanced LPS-induced necrosis, not apoptosis. The enhanced liver necrosis appears to involve an increase in oxidative and nitrosative stress generated by the combination of LPS plus elevated CYP2E1 levels.


2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Abdulla Y. Al-Taher ◽  
Mohamed A. Morsy ◽  
Rehab A. Rifaai ◽  
Nagwa M. Zenhom ◽  
Seham A. Abdel-Gaber

Methotrexate (MTX) is a commonly used chemotherapeutic agent. Oxidative stress and inflammation have been proved in the development of MTX toxicity. Paeonol is a natural phenolic compound with various pharmacological activities including antioxidant and anti-inflammatory properties. The aim of the present study was to evaluate the protective effect of paeonol against MTX-induced cardiac toxicity in rats and to evaluate the various mechanisms that underlie this effect. Paeonol (100 mg/kg) was administered orally for 10 days. MTX cardiac toxicity was induced at the end of the fifth day of the experiment, with or without paeonol pretreatment. MTX-induced cardiac damage is evidenced by a distortion in the normal cardiac histological structure, with significant oxidative and nitrosative stress shown as a significant increase in NADPH oxidase-2, malondialdehyde, and nitric oxide levels along with a decrease in reduced glutathione concentration and superoxide dismutase activity compared to the control group. MTX-induced inflammatory effects are evidenced by the increased cardiac toll-like receptor 4 (TLR4) mRNA expression and protein level as well as increased cardiac tumor necrosis factor- (TNF-) α and interleukin- (IL-) 6 levels along with increased nuclear factor- (NF-) κB/p65 immunostaining. MTX increased apoptosis as shown by the upregulation of cardiac caspase 3 immunostaining. Paeonol was able to correct the oxidative and nitrosative stress as well as the inflammatory and apoptotic parameters and restore the normal histological structure compared to MTX alone. In conclusion, paeonol has a protective effect against MTX-induced cardiac toxicity through inhibiting oxidative and nitrosative stress and suppressing the TLR4/NF-κB/TNF-α/IL-6 inflammatory pathway, as well as causing an associated reduction in the proapoptotic marker, caspase 3.


2007 ◽  
Vol 26 (12) ◽  
pp. 923-932 ◽  
Author(s):  
CK Veena ◽  
A Josephine ◽  
SP Preetha ◽  
P Varalakshmi

Kidney stones are known to haunt humanity for centuries and increase in oxalate is a predominant risk factor for stone formation. The present study was initiated with a notion to study the oxidative and nitrosative stress on erythrocytes under oxalate stress and the putative role of sulphated polysaccharides. Hyperoxaluria was induced in two groups by the administration of 0.75% ethylene glycol in drinking water for 28 days and one of them was treated with sulphated polysaccharides from Fucus vesiculosus from the 8th day to the end of the experimental period of 28 days at a dose of 5 mg/kg body weight subcutaneously. Control and drug control (sulphated polysaccharides alone) were also included in the study. Glycolic and glyoxylic acid levels of urine were analyzed as an index of hyperoxaluria. The plasma enzymic markers of cellular integrity, redox status of red blood cells, osmotic fragility, and 14C-oxalate binding were investigated. Urine and plasma nitric oxide metabolites, expression of inducible nitric oxide synthase protein, and mRNA were assessed in kidney to evaluate the nitrosative stress. Increased levels of glycolic and glyoxylic acid in urine indicated the prevalence of hyperoxaluria in ethylene glycol–administered groups. Plasma aspartate and alanine transaminase were not altered, but alkaline phosphatase and lactate dehydrogenase of hyperoxaluric group were increased indicating tissue damage. Activities of antioxidant enzymes were decreased, whereas erythrocyte membrane lipid peroxidation was increased in hyperoxaluric rats. Moreover, an altered fragility with an increase in oxalate binding activity was observed in hyperoxaluric group. Increase in nitric oxide metabolites levels in urine and plasma along with an increase in expression of inducible nitric oxide synthase protein and mRNA in kidney were observed in hyperoxaluric rats. Administration of sulphated polysaccharides to hyperoxaluric rats averted the abnormal increase in urinary glycolic and glyoxylic acid levels and enzyme activities, decreased lipid peroxidation, and increased the activities of antioxidant enzymes. Furthermore, increased nitrosative stress accompanying hyperoxaluria was also normalized on sulphated polysaccharides treatment. To conclude, sulphated polysaccharide administration was able to maintain the integrity of erythrocyte membrane and decrease the damage to erythrocytes in hyperoxaluria.


Sign in / Sign up

Export Citation Format

Share Document