诱导痰技术在慢性阻塞性肺疾病患者氧化应激机制研究中的应用

目的利用谤导痰技术研究慢性阻塞性肺疾病(COPD)患者气道局部氧化应激水平的变化及其与COPD患者肺功能下降的关系。方法对40例急性加重期COPD患者(A组)、30例稳定期COPD患者(B组)、15例健康吸烟者(C组)进行痰诱导,并测定其诱导痰中脂质过氧化产物丙二醛(MDA)、非酶性抗氧化剂还原型谷胱甘肽(GSH)含量、酶性抗氧化剂超氧化物歧化酶(SOD)活性及谷胱甘肽过氧化物酶(GSH-PX)活性,并分析各指标与肺功能的关系。结果(1)COPD患者在痰诱导前和结束时及结束10min SpO_2、FEV_1均值比较变化无统计学意义(P>0.05);(2)A、B、C组间诱导痰MDA含量呈下降趋势,诱导痰GSH含量、SOD、GSH-PX活性呈上升趋势;(3)FEV_1与痰MDA、GSH含量及痰SOD、GSH-PX的活性相关系数分别为-0.776、0.778、0.788、0.800,P<0.05。结论痰诱导技术在COPD患者氧化应激机制研究中的应用具有一定的安全性,COPD患者气道局部均存在氧化/抗氧化失衡,尤以急性加重期患者更为明显,COPD患者氧化应激增加是导致肺功能下降的原因之一。     

Seizures,antiepileptics, antioxidants and oxidative stress: an insight for researchers

Background: Neuronal hyperexcitability and excessive production of free radicals have been implicated in the pathogenesis of a considerable range of neurological disorders, including epilepsy. The high rate of oxidative metabolism, coupled with the low antioxidant defenses and the richness in polyunsaturated fatty acids, makes the brain highly vulnerable to free radical damage. The increased susceptibility of the brain to oxidative damage highlights the importance of understanding the role of oxidative stress in the pathophysiology of seizures. Objectives: The present review aims not only to address the link between mitochondrial dysfunction, oxidative stress and seizures, but also the modulation of the pro-oxidant/antioxidant balance following seizures and treatment with antioxidants and antiepileptic drugs. Methods: A literature review revealed that there are articles that address the role of oxidative stress and mitochondrial dysfunction in neurological disorders, including those involving different seizure models where the modulation of the pro-oxidant/antioxidant balance by seizures per se and by antioxidant agents is discussed. However, the critical role of oxidative stress in all seizure models is not uniform. Therefore, there is a need for a review article that will address all these issues together. Results/conclusions: The experimental and clinical data suggest a putative role of oxidative stress in the pathophysiology of certain seizure types. The pro-oxidant/antioxidant balance is not only modulated by seizures per se, but also by antiepileptic drugs. The ability of antioxidants for reducing the seizure manifestations and the accompanying biochemical changes (i.e., markers of oxidative stress) further supports a role of free radicals in seizures and highlights a possible role of antioxidants as adjuncts to antiepileptic drugs for better seizure control.     

白藜芦醇对脑缺血/再灌注氧化应激损伤保护机制的研究进展

白藜芦醇是一种广泛存在于植物中的多酚类化合物,具有广泛的生物学活性。该文主要从白藜芦醇的性质以及在脑缺血/再灌注氧化应激损伤中的保护作用及其机制作一综述。     

Homologous recombination initiated by benzene metabolites: a potential role of oxidative stress.

Benzene is a ubiquitous pollutant and known human leukemogen. Benzene can be enzymatically bioactivated to reactive intermediates that can lead to increased formation of reactive oxygen species (ROS). ROS formation can directly induce DNA double-strand breaks, and also oxidize nucleotides that are subsequently converted to double-strand breaks during DNA replication that can be repaired through homologous recombination, which is not error-free. Therefore increased DNA double-strand-break levels may induce hyper-recombination, which can lead to deleterious genetic changes. To test the hypothesis that benzene and its metabolites can initiate hyper-recombination and to investigate the potential role of ROS, a Chinese hamster ovary (CHO) cell line containing a neo direct repeat recombination substrate (CHO 3-6), was used to determine whether benzene or its metabolites phenol, hydroquinone, catechol, or benzoquinone initiated increased homologous recombination and whether this increase could be diminished by the coincubation of cells with the antioxidative enzyme catalase. Results demonstrated that cells exposed to benzene (1, 10, 30, or 100 micro M) for 24 h did not exhibit increased homologous recombination. Increased recombination occurred with exposure to phenol (1.8-, 2.6-, or 2.9-fold), catechol (1.9-, 2-, 5-, or 3.2-fold), or benzoquinone (2.7-, 5.5-, or 6.9-fold) at 1, 10, and 30- micro M concentrations, respectively, and with exposure to hydroquinone at 10 and 30 micro M concentrations (1.5-1.9-fold; p < 0.05). Studies investigating the effects of catalase demonstrated that increased homologous recombination due to exposure to phenol, hydroquinone, catechol, or benzoquinone (10 micro M) could be completely abolished by the addition of catalase. These data support the hypothesis that increased homologous recombination mediates benzene-initiated toxicity and supports a role for oxidative stress in this mechanism.     

Alteration of lipid status and lipid metabolism,induction of oxidative stress and lipid peroxidation by 2,4-dichlorophenoxyacetic herbicide in rat liver

Abstract

This study aims to investigate the effects of the 2,4-dichlorophenoxyacetic herbicide (2,4-D) on plasma lipids, lipoproteins concentrations, hepatic lipid peroxidation, fatty acid composition and antioxidant enzyme activities in rats. Animals were randomly divided into four groups of 10 each: control group and three 2,4-D-treated groups G1, G2 and G3 were administered 15, 75 and 150?mg/kg/BW/d 2,4-D by gavage for 28?d, respectively. Results showed that 2,4-D caused significant negative changes in the biochemical parameters investigated. The malondialdehyde level was significantly increased in 2,4-D-treated groups. Fatty acid composition of the liver was also significantly changed with 2,4-D exposure. Furthermore, the hepatic antioxidant enzyme activities were significantly affected. Finally, 2,4-D at the studied doses modifies lipidic status, disrupt lipid metabolism and induce hepatic oxidative stress. In conclusion, at higher doses, 2,4-D may play an important role in the development of vascular disease via metabolic disorder of lipoproteins, lipid peroxidation and oxidative stress.     

Toxicity of the quinalphos metabolite 2-hydroxyquinoxaline: growth inhibition, induction of oxidative stress, and genotoxicity in test organisms

The quinalphos metabolite 2-hydroxyquinoxaline (HQO), previously shown to photocatalytically destroy antioxidant vitamins and biogenic amines in vitro, was tested for toxicity in several small aquatic organisms and for mutagenicity in Salmonella typhimurium. In the rotifer Philodina acuticornis, HQO caused the disappearance of large individuals and increased hydroperoxide concentration. The latter effect was not only observed in animals kept in a light/dark cycle, but also in constant darkness, indicating that HQO can assume a reactive state and/or form reactive intermediates under the influence of either light or redox-active metabolites, in particular, free radicals. Cell proliferation was inhibited in the ciliate Paramecium bursaria. In the dinoflagellate Lingulodinium polyedrum, which allows early detection of cellular stress on the basis of bioluminescence measurements, strong rises in light emission became apparent on the 2nd day of exposure to HQO and continued until cells died between 12 and 18 days of treatment. Oxidative damage of protein by HQO was demonstrated by measuring protein carbonyl in L. polyedrumin vivo as well as in light-exposed bovine serum albumin in vitro. In an Ames test of mutagenicity, HQO proved to be genotoxic in both light- and dark-exposed bacteria. HQO appears as a source of secondary quinalphos toxicity, which deserves further attention.     

Thiol/disulfide homeostasis as a marker of oxidative stress in rosacea: a controlled spectrophotometric study

Background: Rosacea is the chronic inflammatory disease of the facial skin. Although its aetiology is not clear yet, inflammatory processes triggered by oxidative stress and oxidation of lipids have been suggested to play a role. While studies on the relationship between inflammation and oxidative stress are ongoing, thiol metabolism and its role in oxidative stress have also begun to be investigated. Thiols are among the key molecules of protein metabolism in the organism and they are the firstly consumed antioxidants in case of oxidative stress. Thiols regulate intracellular redox metabolism and protect keratinocytes against the results of oxidative alterations in the stratum corneum. There is a balance known as dynamic thiol/disulfide homeostasis between thiols and their oxidized forms; disulfides.

Aim: This study aimed to determine the effects of oxidative stress on protein metabolism in rosacea patients by investigating thiol/disulfide homeostasis using a newly developed and fully automated method. Determination of plasma thiol levels provides important clues regarding the extent of free radical-mediated oxidation of proteins causing damage in rosacea.

Methods: The study included 50 rosacea patients who were diagnosed clinically or histopathologically with rosacea and 42 age- and gender-matched healthy controls. Plasma levels of native thiol, total thiol, and disulfide were determined. The following ratios were calculated: disulfide/native thiol ratio, disulfide/total thiol ratio, and native thiol/total thiol ratio.

Results: The mean age was 41.8?±?10.5 in the rosacea patients (35 females) and 42.5?±?10.3?years in the control group (33 females). The mean disulfide level was found to be significantly higher in the rosacea patients than in the control group (23.4?±?5.5?µM/L and 17.3?±?6.2µM/L, respectively; p?p?Conclusion: In rosacea patients, the thiol/disulfide balance was observed to shift towards disulfides, which could be considered an indicator of oxidative stress in rosacea.     

Effect of five acetylcholinesterase reactivators on tabun‐intoxicated rats: induction of oxidative stress versus reactivation efficacy

Oxime reactivators HI‐6, obidoxime, trimedoxime, K347 and K628 were investigated as drugs designed for treatment of tabun intoxication. The experiments were performed on rats in order to simulate real conditions. Rats were intoxicated with one LD₅₀ of tabun and treated with atropine and mentioned reactivators. Activities of erythrocyte acetylcholinesterase (AChE), plasma butyrylcholinesterase (BChE) and brain AChE were measured as markers of reactivation efficacy. An estimation of low molecular weight antioxidant levels using cyclic voltammetry was the second examination parameter. The evaluation of cholinesterases activity showed good reactivation potency of blood AChE and plasma BChE by commercially available obidoxime and newly synthesized K347. The potency of oximes to reactivate brain AChE was lower due to the poor blood–brain barrier penetration of used compounds. Commercially available reactivator HI‐6 and newly synthesized K628 caused oxidative stress measured by cyclic voltammetry as antioxidant level. The oxidative stress provoked by HI‐6 and K628 was found to be significant on probability level P = 0.05. The others reactivators did not affect antioxidant levels. Copyright © 2009 John Wiley & Sons, Ltd.     

Novel findings for the development of drug therapy for various liver diseases: Liver microsomal triglyceride transfer protein activator may be a possible therapeutic agent in non-alcoholic steatohepatitis

The factors involved in the progression of non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH) are not fully understood and thus it is urgently needed to elucidate these factors. Steatosis is not causal in the development of NASH, but rather it sensitizes the liver to the damaging effects of second hits such that stressors innocuous to a healthy liver lead to the development of NASH in the steatotic liver. In the previous study, most of the hepatic lipid metabolite profiles were similar in the NAFL and NASH groups. However, very-low-density lipoprotein (VLDL) synthesis, especially hepatic microsomal triglyceride transfer protein (MTP) mRNA expression, was impaired in the NASH group. Moreover, NASH showed significantly higher incidence of minor alley appearance compared with NAFL, indicating the possibility of association between NASH pathogenesis and decreased congenital MTP activity. MTP is one of the enzymes that transfer triglycerides to nascent apolipoprotein B, producing VLDL and removing lipid from the hepatocyte. A growing body of literature suggests that the measurement of hepatic MTP expression may be helpful for diagnosis; and moreover, hepatic MTP activator may be a possible therapeutic agent for the treatment of NASH.     

Effects of TBEP on the induction of oxidative stress and endocrine disruption in Tm3 Leydig cells

The flame retardant tris (2‐butoxyethyl) phosphate (TBEP) is a frequently detected contaminant in the environment. In the cultured TM3 cells (originated from ATCC), effects of TBEP on the induction of oxidative stress and endocrine disruption were evaluated. It was observed that exposure to 100 μg/mL TBEP for 24 h significantly reduced the viability of TM3 cells. The mRNA levels of genes related to oxidative stress including Sod, Gpx1, Cat, and Gsta1 were changed in a dose‐dependent and/or time‐dependent manner after exposure to 30 and 100 μg/mL TBEP for 6, 12, or 24 h. Moreover, notable decrease in glutathione (GSH) contents and increases in oxidized glutathione (GSSG) contents as well as the antioxidant enzyme activities like superoxide dismutase, catalase, glutathione peroxidase, and glutathione S‐transferase were found in the group treated with 100 μg/mL TBEP for 24 h, indicating that TBEP induced oxidative stress in TM3 Leydig cells. In addition, the expression of genes related to testosterone (T) synthesis including cytochrome P450 cholesterol side‐chain cleavage enzyme (P450scc), cytochrome P450 17α‐hydroxysteroid dehydrogenase (P450‐17α), and 17β‐hydroxysteroid dehydrogenase (17β‐HSD) and T levels in medium were remarkably declined by the treatment of 100 μg/mL TBEP for 24 h. And TBEP could inhibit the expression of P450‐17α and 17β‐HSD and T levels up‐regulated by hCG in TM3 cells. Taken together, these findings indicated that TBEP can induce oxidative stress and alter steroidogenesis in TM3 cells. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1276–1286, 2016.     

Mechanisms for the induction of oxidative stress in Syrian hamster embryo cells by acrylonitrile.

Chronic administration of acrylonitrile to rats resulted in an increase in the incidence of glial neoplasms of the brain. Recent studies have shown that acrylonitrile induces oxidative stress in rat brain and cultured rat glial cells. Acrylonitrile also induces morphological transformation concomitant with an increase in the formation of oxidized DNA in Syrian Hamster Embryo (SHE) cells in a dose-dependent manner. The mechanism for the induction of oxidative stress in SHE cells remains unresolved. The present study examined the effects of acrylonitrile on enzymatic and nonenzymatic antioxidants in SHE cells. SHE cells were treated with subcytolethal doses of acrylonitrile (0, 25, 50, and 75 microg/ml) for 4, 24, and 48 h. Acrylonitrile (50 microg/ml and 75 microg/ml) increased the amount of reactive oxygen species in SHE cells at all time points. Glutathione (GSH) was depleted and catalase and superoxide dismutase activities were significantly decreased in SHE cells after 4 h of treatment. The inhibition of these antioxidants was temporal, returning to control values or higher after 24 and 48 h. Xanthine oxidase activity was increased following 24 and 48 h treatment with acrylonitrile. 1-aminobenzotriazole, a suicidal P450 enzyme inhibitor, attenuated the effects of acrylonitrile on catalase and xanthine oxidase in SHE cells, suggesting that P450 metabolism is required for acrylonitrile to produce its effects on these enzymes. Additional studies showed that in the absence of metabolic sources acrylonitrile had no effect on either catalase or superoxide dismutase activity. These results suggest that the induction of oxidative stress by acrylonitrile involves a temporal decrease in antioxidants and increase in xanthine oxidase activity that is mediated by oxidative metabolism of acrylonitrile.     

Cyto‐genotoxicity and oxidative stress in common carp (Cyprinus carpio) exposed to a mixture of ibuprofen and diclofenac

Thirty million people worldwide consume each day nonsteroidal anti‐inflammatory drugs (NSAIDs), a heterogeneous group of pharmaceuticals used for its analgesic, antipyretic, and anti‐inflammatory properties. Recent studies report high NSAID concentrations in wastewater treatment plant effluents, in surface, ground, and drinking water, and in sediments. NSAIDs are also known to induce toxicity on aquatic organisms. However, toxicity in natural ecosystems is not usually the result of exposure to a single substance but to a mixture of toxic agents, yet only a few studies have evaluated the toxicity of mixtures. The aim of this study was to evaluate the toxicity induced by diclofenac (DCF), ibuprofen (IBP), and their mixture on a species of commercial interest, the common carp Cyprinus carpio. The median lethal concentration of IBP and DCF was determined, and oxidative stress was evaluated using the following biomarkers: lipid peroxidation and activity of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase. Cyto‐genotoxicity was evaluated by micronucleus test, comet assay, and the specific activity of caspase‐3. Results show that DCF, IBP, and a mixture of these pharmaceuticals induced free radical production, oxidative stress and cyto‐genotoxicity in tissues of C. carpio. However, a greater effect was elicited by the mixture than by either pharmaceutical alone in some biomarkers evaluated, particularly in gill. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1637–1650, 2017.     

Toxic effects of hexaammine cobalt(III) chloride on liver and kidney in mice: Implication of oxidative stress

Hexaammine cobalt (III) chloride is a trivalent complex cation of Co(III) and amine that has previously been shown to act as an inhibitor of insulin secretion, radiosensitizing agent, and an antiviral agent. We have recently reported the anticancer potential of the compound against diethylnitrosamine-induced carcinogenesis in mice. However, there is no report on the potential toxicity of the compound. The present study was conducted to evaluate the tissue distribution of the compound and its potential toxicity following acute administration of the compound through intraperitoneal route in Balb/c mice. Our results showed that cobalt accumulated maximally in kidney, followed by liver, spleen, blood, and lung in a decreasing order and in a dose-dependent manner. Evaluation of liver and kidney function tests revealed that the compound exerted a relatively higher toxicity in kidney, as compared to liver, as evidenced by the sharp enhancement in the serum levels of urea and creatinine in a dose-dependent manner. Examination of levels of lipid peroxidation and selected oxidative stress–related parameters in kidney, liver, and lung suggest that higher accumulation of cobalt in kidney may promote higher oxidative stress in the organ, as compared to liver and lung, which may eventually impair kidney function.     

The role of GSH in microcystin‐induced apoptosis in rat liver: Involvement of oxidative stress and NF‐κB

Microcystins (MCs) are potent and specific hepatotoxins produced by cyanobacteria in eutrophic waters, representing a health hazard to animals and humans. The objectives of this study are to determine the relationship between oxidative stress and NF‐κB activity in MC‐induced apoptosis in rat liver and the role of glutathione (GSH). Sprague‐Dawley rats were intraperitoneally (i.p.) injected with microcystin‐LR (MC‐LR) at 0.25 and 0.5 LD₅₀ with or without pretreatment of buthionine‐(S,R)‐sulfoximine (BSO), a specific GSH synthesis inhibitor. MC‐LR induced time‐dependent alterations of GSH levels in rat liver. Increased malondialdehyde (MDA) and significant changes of antioxidant enzymes including GSH peroxidase (GPX) and GSH reductase (GR) were also observed, particularly at 24 h post‐exposure. The results indicated that acute exposure to MC‐LR induced oxidative stress, and GSH depletion (BSO pretreatment) enhanced the level of oxidative stress. Furthermore, the modulation of pro‐apoptotic gene p53 and Bax and anti‐apoptotic gene Bcl‐2 was observed in 0.5 LD₅₀ group at 24 h, and the alteration was more pronounced by BSO injection before MC‐LR treatment, suggesting that GSH played a protective role against MC‐induced toxicity. Additionally, electrophoretic mobility shift assay (EMSA) showed that NF‐κB was induced at 0.25 LD₅₀ but inhibited at 0.5 LD₅₀. The above results indicated that the possible crosstalk of oxidative stress and NF‐κB activity was associated with MC‐LR‐induced hepatocytes apoptosis in vivo. Our data will provide a new perspective for understanding the mechanisms of MC‐induced liver injury. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 552–560, 2016.     

洛匹那韦/利托那韦的不良反应及其机制研究进展

洛匹那韦/利托那韦主要用于人类免疫缺陷（艾滋病）病毒感染的治疗,临床上超说明书用于新型冠状病毒感染的治疗。临床发现使用该药后易引发多种不良反应,主要包括胃肠道反应、肝损伤、代谢紊乱、心血管和神经毒性不良反应。洛匹那韦/利托那韦不良反应机制可能与内质网应激、氧化应激、线粒体应激、细胞凋亡等有关,具有剂量相关性,剂量越高则不良反应越大,主要由肝脏CYP3A代谢,当其与某些具有较强CYP3A4抑制作用的药物共同使用时,往往会加重其不良反应。综述了洛匹那韦/利托那韦片的不良反应及其发生机制,为临床安全、合理用药提供参考。     

Human hepatic microsomal sulfatase catalyzes the hydrolysis of polychlorinated biphenyl sulfates: A potential mechanism for retention of hydroxylated PCBs

Polychlorinated biphenyls (PCBs) are persistent environmental contaminants that continue to be of concern due to their varied toxicities. Upon human exposure, many PCBs with lower numbers of chlorine atoms are metabolized to hydroxylated derivatives (OH-PCBs), and cytosolic sulfotransferases can subsequently catalyze the formation of PCB sulfates. Recent studies have indicated that PCB sulfates bind reversibly with a high affinity to human serum proteins, and that they are also taken up by cells and tissues. Since PCB sulfates might be hydrolyzed to the more toxic OH-PCBs, we have investigated the ability of human hepatic microsomal sulfatase to catalyze this reaction. Twelve congeners of PCB sulfates were substrates for the microsomal sulfatase with catalytic rates exceeding that of dehydroepiandrosterone sulfate as a comparison substrate for steroid sulfatase (STS). These results are consistent with an intracellular mechanism for sulfation and de-sulfation that may contribute to retention and increased time of exposure to OH-PCBs.     

Toxicokinetics of new psychoactive substances: plasma protein binding,metabolic stability,and human phase I metabolism of the synthetic cannabinoid WIN 55,212‐2 studied using in vitro tools and LC‐HR‐MS/MS

The new psychoactive substance WIN 55,212‐2 ((R)‐(+)‐[2,3‐dihydro‐5‐methyl‐3‐(4‐morpholinylmethyl)pyrrolo‐[1,2,3‐de]‐1,4‐benzoxazin‐6‐yl]‐1‐napthalenylmethanone) is a potent synthetic cannabinoid receptor agonist. The metabolism of WIN 55,212‐2 in man has never been reported. Therefore, the aim of this study was to identify the human in vitro metabolites of WIN 55,212‐2 using pooled human liver microsomes and liquid chromatography‐high resolution‐tandem mass spectrometry (LC‐HR‐MS/MS) to provide targets for toxicological, doping, and environmental screening procedures. Moreover, a metabolic stability study in pooled human liver microsomes (pHLM) was carried out. In total, 19 metabolites were identified and the following partly overlapping metabolic steps were deduced: degradation of the morpholine ring via hydroxylation, N‐ and O‐dealkylation, and oxidative deamination, hydroxylations on either the naphthalene or morpholine ring or the alkyl spacer with subsequent oxidation, epoxide formation with subsequent hydrolysis, or combinations. In conclusion, WIN 55,212‐2 was extensively metabolized in human liver microsomes incubations and the calculated hepatic clearance was comparably high, indicating a fast and nearly complete metabolism in vivo. This is in line with previous findings on other synthetic cannabinoids. Copyright © 2016 John Wiley & Sons, Ltd.     

The role of cellular oxidoreductases in viral entry and virus infection-associated oxidative stress: potential therapeutic applications

Introduction: Cellular oxidoreductases catalyze thiol/disulfide exchange reactions in susceptible proteins and contribute to the cellular defense against oxidative stress. Oxidoreductases and oxidative stress are also involved in viral infections. In this overview, different aspects of the role of cellular oxidoreductases and oxidative stress during viral infections are discussed from a chemotherapeutic viewpoint.

Areas covered: Entry of enveloped viruses into their target cells is triggered by the interaction of viral envelope glycoproteins with cellular (co)receptor(s) and depends on obligatory conformational changes in these viral envelope glycoproteins and/or cellular receptors. For some viruses, these conformational changes are mediated by cell surface-associated cellular oxidoreductases, which mediate disulfide bridge reductions in viral envelope glycoprotein(s). Therefore, targeting these oxidoreductases using oxidoreductase inhibitors might yield an interesting strategy to block viral entry of these viruses. Furthermore, since viral infections are often associated with systemic oxidative stress, contributing to disease progression, the enhancement of the cellular antioxidant defense systems might have potential as an adjuvant antiviral strategy, slowing down disease progression.

Expert opinion: Promising antiviral data were obtained for both strategies. However, potential pitfalls have also been identified for these strategies, indicating that it is important to carefully assess the benefits versus risks of these antiviral strategies.