Protective effects of ethyl pyruvate treatment on paraquat-intoxicated rats

2008 ◽  
Vol 27 (1) ◽  
pp. 49-54 ◽  
Author(s):  
JH Lee ◽  
WY Kwon ◽  
YH Jo ◽  
GJ Suh ◽  
YK Youn

Although, numerous studies have attempted to reduce the oxygen radical injury induced by the antioxidants in paraquat intoxication, these antioxidant therapies have showed few survival benefits. Ethyl pyruvate (EP) may function as an effective scavenger of oxygen radicals, an anti-inflammatory agent and an energy source in many ischemia reperfusion models. The aim of this study was to evaluate the antioxidant and anti-inflammatory effects of EP on the lung and the liver tissues in paraquat-intoxicated rats. Rats were randomly given either a low (2 mg/kg i.p.) or high (40 mg/kg i.p.) EP dose, 30 min before or 1 h after paraquat (50 mg/kg i.p.) administration, and subsequently killed at 6 and 24 h. Glutathione (GSH) and malondialdehyde (MDA) levels of the lungs and the livers, and plasma nitric oxide (NO) concentrations were measured. Pretreatment of EP significantly decreased the MDA level in the lung and the liver tissues. EP also significantly decreased plasma NO concentrations at 6 h. EP pretreatment, however, failed to show significant change in GSH concentration. In post-treatment of EP, MDA levels in the lung tissue and plasma NO levels were significantly decreased. In conclusion, EP decreased the lipid peroxidation and seemed to exert an anti-inflammatory action in the paraquat intoxication rat model.

1997 ◽  
Vol 273 (3) ◽  
pp. L504-L512 ◽  
Author(s):  
Y. C. Huang ◽  
P. W. Fisher ◽  
E. Nozik-Grayck ◽  
C. A. Piantadosi

Because both the biosynthesis of nitric oxide (NO.) and its metabolic fate are related to molecular O2, we hypothesized that hypoxia would alter the effects of NO. during ischemia-reperfusion (IR) in the lung. In this study, buffer-perfused lungs from rabbits underwent either normoxic IR (AI), in which lungs were ventilated with 21% O2 during ischemia and reperfusion, or hypoxic IR (NI), in which lungs were ventilated with 95% N2 during ischemia followed by reoxygenation with 21% O2. Lung weight gain (WG) and pulmonary artery pressure (Ppa) were monitored continuously, and microvascular pressure (Pmv) was measured after reperfusion to calculate pulmonary vascular resistance. We found that both AI and NI produced acute lung injury, as shown by increased WG and Ppa during reperfusion. In AI, where perfusate PO2 was > 100 mmHg, the administration of the NO. synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME) before ischemia worsened WG and Ppa. Pmv also increased, suggesting a hydrostatic mechanism involved in edema formation. The effects of L-NAME could be attenuated by giving L-arginine and exogenous NO. donors before ischemia or before reperfusion. Partial protection was also provided by superoxide dismutase. In contrast, lung injury in NI at perfusate PO2 of 25-30 mmHg was attenuated by L-NAME; this effect could be reversed by L-arginine. Exogenous NO. donors given either before ischemia or before reperfusion, however, did not increase lung injury. NO. production was measured by quantifying the total nitrogen oxides (NOx) accumulating in the perfusate. The average rate of NOx accumulation was greater in AI than in NI. We conclude that hypoxia prevented the protective effects of NO on AI lung injury. The effects of hypoxia may be related to lower NO. production relative to oxidant stress during IR and/or altered metabolic fates of NO.-mediated production of peroxynitrite by hypoxic ischemia.


Author(s):  
Gazanfar Ahmad ◽  
Reyaz Hassan ◽  
Neerupma Dhiman ◽  
Asif Ali

Background: Pentacyclic triterpenoids are a biologically active class of phytoconstituents with diverse pharmacological activity including anti-inflammatory action. Objective: In the current study, we isolated 3-Acetylmyricadiol, a pentacyclic triterpenoid, from the ethyl acetate bark-extract of Myrica esculenta and evaluated it for anti-inflammatory potential. Methods: The ethyl acetate bark-extract of the M. esculenta was subjected to column chromatography to isolate 3-Acetylmyricadiol. MTT assay was performed to check cell viability. The production of proinflammatory mediators like Nitric oxide, IL-6, TNF-α was observed after administration of 5, 10, 20 μM of 3-Acetylmyricadiol in LPS-activated Raw 246.7 macrophages by the reported methods. Results: MTT assay indicated more than 90% cell viability up to 20 μM of 3-Acetylmyricadiol. The administration of 3-Acetylmyricadiol inhibited the production of Nitric oxide, IL-6, TNF-α in a dose-dependent manner significantly in comparison to LPS treated cells. The maximum effect was observed at 20 μM of 3-Acetylmyricadiol which resulted in 52.37, 63.10, 55.37 % inhibition of Nitric oxide, IL-6, TNF-α respectively. Conclusion: Our study demonstrated the anti-inflammatory action of 3-Acetylmyricadiol and can serve as a potential candidate in the development of the clinically efficient anti-inflammatory molecule.


2020 ◽  
Vol 11 (4) ◽  
pp. 417-423 ◽  
Author(s):  
Chawki Elzein ◽  
Cynthia Urbas ◽  
Bonnie Hughes ◽  
Yi Li ◽  
Cheryl Lefaiver ◽  
...  

Objective: Nitric oxide (NO) plays several protective roles in ischemia/reperfusion (I/R) injury. Neonates undergoing the Norwood procedure are subject to develop I/R injury due to the immaturity of their organs and the potential need to interrupt or decrease systemic flow during surgery. We hypothesized that NO administration during cardiopulmonary bypass (CPB) ameliorates the I/R and could help the postoperative recovery after the Norwood procedure. Methods: Twenty-four neonates who underwent a Norwood procedure were enrolled in a prospective randomized blinded controlled trial to receive NO (12 patients) or placebo (12 patients) into the oxygenator of the CPB circuit during the Norwood procedure. Markers of I/R injury were collected at baseline (T0), after weaning from CPB before modified ultrafiltration (T1), after modified ultrafiltration (T2), and at 12 hours (T3) and 24 hours (T4) after surgery, and they were compared between both groups, as well as other postoperative clinical variables. Results: There was no difference in age, weight, anatomical diagnosis, CPB, and aortic cross-clamp time between both groups. Troponin levels were lower in the study group at T1 (0.62 ± 58 ng/mL vs 0.87 ± 0.58 ng/mL, P = .31) and became significantly lower at T2 (0.36 ± 0.32 ng/mL vs 0.97 ± 0.48 ng/mL, P = .009).There were no significant differences between both groups for all other markers. Despite a lower troponin level, there was no difference in inotropic scores or ventricular function between both groups. Time to start diuresis, time to sternal closure and extubation, and intensive care unit and hospital stay were not different between both groups. Conclusion: Systemic administration of NO during the Norwood procedure has myocardial protective effects (lower Troponin levels) but we observed no effect on postoperative recovery. Larger sample size may be needed to show clinical differences.


2013 ◽  
Vol 634-638 ◽  
pp. 1357-1361
Author(s):  
Xin Ling ◽  
Xiao Bin Fu ◽  
Li Liu ◽  
Xia Tian ◽  
Ling Yan Sun ◽  
...  

To observe the protective effects of L-citrulline on the renal ischemia-reperfusion (I/R) injury and elucidate the mechanisms involved. Forty-eight rats were randomized into eight groups. At the end of the reperfusion period, serum was collected and the kidneys were removed for histological and biochemical examinations. Our results showed that pretreatment with L-citrulline significantly ameliorated the renal injury caused by I/R. Moreover, L-citrulline increased the levels of NO. The I/R-induced decreases in total nitric oxide synthase (NOS) activity, inducible NOS activity and constitutive NOS activity in the renal cortex were significantly prevented. These results suggested that L-citrulline administration exhibited significant protection on renal I/R injury.


1996 ◽  
Vol 80 (3) ◽  
pp. 782-788 ◽  
Author(s):  
F. Barbotin-Larrieu ◽  
M. Mazmanian ◽  
B. Baudet ◽  
H. Detruit ◽  
A. Chapelier ◽  
...  

Lung ischemia-reperfusion results in a decrease in the release of nitric oxide (NO) by the pulmonary endothelium. NO may have lung-protective effects by decreasing neutrophil accumulation in the lung. We tested whether NO inhalation would attenuate reperfusion-induced endothelial dysfunction and increases in microvascular permeability and total pulmonary vascular resistance (RT) by preventing neutrophil lung accumulation. After baseline determinations of RT, coefficient of filtration (Kfc), and circulating neutrophil counts, isolated neonatal piglet lungs were subjected to a 1-h period of ischemia followed by a 1-h period of blood reperfusion and reventilation with or without addition of NO (10 ppm). NO prevented reperfusion-induced increases in RT and Kfc, as well as the decrease in circulating neutrophils. After reperfusion, increases in Kfc were correlated with decreases in circulating neutrophils. NO prevented reperfusion-induced decrease in endothelium-dependent relaxation in precontracted pulmonary arterial rings. This demonstrates that inhaled NO prevents microvascular injury, endothelial dysfunction, and pulmonary neutrophil accumulation in a neonatal piglet model of lung ischemia-reperfusion.


2015 ◽  
Vol 35 (2) ◽  
pp. 516-528 ◽  
Author(s):  
Jianchun Huang ◽  
Xudong Zhang ◽  
Feizhang Qin ◽  
Yingxin Li ◽  
Xiaoqun Duan ◽  
...  

Background: Previous studies have demonstrated that Millettia pulchra flavonoids (MPF) exhibit protective effects on myocardial ischemia reperfusion injury (MI/RI) in isolated rat hearts and show anti-oxidative, anti-hypoxic and anti-stress properties. Methods: In this study, the cardioprotective effects of MPF on myocardial ischemia and its underlying mechanisms were investigated by a hypoxia/ reoxygenation (H/R) injury model in vitro and a rat MI/RI model in vivo. Results: We found that the lactate dehydrogenase (LDH) and inducible nitric oxide synthase (iNOS) activities were decreased in the MPF pretreatment group, whereas the activities of constructional nitric oxide synthase (cNOS), total nitric oxide synthase (tNOS), Na+-K+-ATPase and Ca2+-Mg2+-ATPase were significantly increased. In addition, the cardiocytes were denser in the MPF groups than in the control group. The mortality rate and apoptosis rate of cardiocytes were significantly decreased. Furthermore, pretreatment with MPF in vivo significantly improved the hemodynamics, decreased malondialdehyde (MDA) abundance, increased the activities of plasma superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreased the expression of the Bax protein and ratio Bax/Bc1-2 ration. Conclusions: These results suggest that MPF is an attractive protective substance in myocardial ischemia due to its negative effects on heart rate and ionotropy, reduction of myocardial oxidative damage and modulation of gene expression associated with apoptosis.


2011 ◽  
Vol 56 (10) ◽  
pp. 700-706
Author(s):  
Samarjit Das ◽  
Mario Falchi ◽  
Aldo Bertelli ◽  
Nilanjana Maulik ◽  
Dipak Das

2011 ◽  
Vol 301 (4) ◽  
pp. H1487-H1495 ◽  
Author(s):  
Emmanuel Eroume A. Egom ◽  
Tamer M. A. Mohamed ◽  
Mamas A. Mamas ◽  
Ying Shi ◽  
Wei Liu ◽  
...  

We investigated whether plasma long-chain sphingoid base (LCSB) concentrations are altered by transient cardiac ischemia during percutaneous coronary intervention (PCI) in humans and examined the signaling through the sphingosine-1-phosphate (S1P) cascade as a mechanism underlying the S1P cardioprotective effect in cardiac myocytes. Venous samples were collected from either the coronary sinus ( n = 7) or femoral vein ( n = 24) of 31 patients at 1 and 5 min and 12 h, following induction of transient myocardial ischemia during elective PCI. Coronary sinus levels of LCSB were increased by 1,072% at 1 min and 941% at 5 min ( n = 7), while peripheral blood levels of LCSB were increased by 579% at 1 min, 617% at 5 min, and 436% at 12 h ( n = 24). In cultured cardiac myocytes, S1P, sphingosine (SPH), and FTY720, a sphingolipid drug candidate, showed protective effects against CoCl induced hypoxia/ischemic cell injury by reducing lactate dehydrogenase activity. Twenty-five nanomolars of FTY720 significantly increased phospho-Pak1 and phospho-Akt levels by 56 and 65.6% in cells treated with this drug for 15 min. Further experiments demonstrated that FTY720 triggered nitric oxide release from cardiac myocytes is through pertussis toxin-sensitive phosphatidylinositol 3-kinase/Akt/endothelial nitric oxide synthase signaling. In ex vivo hearts, ischemic preconditioning was cardioprotective in wild-type control mice (Pak1f/f), but this protection appeared to be ineffective in cardiomyocyte-specific Pak1 knockout (Pak1cko) hearts. The present study provides the first direct evidence of the behavior of plasma sphingolipids following transient cardiac ischemia with dramatic and early increases in LCSB in humans. We also demonstrated that S1P, SPH, and FTY720 have protective effects against hypoxic/ischemic cell injury, likely a Pak1/Akt1 signaling cascade and nitric oxide release. Further study on a mouse model of cardiac specific deletion of Pak1 demonstrates a crucial role of Pak1 in cardiac protection against ischemia/reperfusion injury.


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