Influence of oestrogens on formation of reactive oxygen species in liver microsomes of differently aged male Wistar rats.

Metabolic pathways of oestrogens are the formation of catechol oestrogens (CE; 2- and 4-hydroxy-oestrogens), redox cycling of CE and free radical generation, mediated through cytochrome P450 (P450) oxidase/reductase activity. We checked the oestrogens oestradiol (E2), oestradiol valerate (E2V) and ethinyloestradiol (EE2) for formation of reactive oxygen species in vitro and ex vivo in male Wistar rats in dependence on age. In liver microsomes of 10-, 30-, 60- and 270-day-old rats the influence of E2, E2V and EE2 (10(-7)-10(-3) M) on NADPH-Fe(++)-stimulated lipid peroxidation (LPO), H2O2 generation and lucigenin (LUC) and luminol (LUM) amplified chemiluminescence (CL) was investigated. The same parameters, additionally P450 content and monooxygenase activities were measured in liver 9000 x g supernatants after subchronic administration of the oestrogens (1, 10 mg/kg b. wt. orally). The most important results are the strong inhibitory capacities of the oestrogens in vitro on LPO in the order of E2V < E2 < EE2, most pronounced in 10-, 60- and 270-day-old animals. In microsomes of 30-day-old rats with the highest control LPO the antioxidative effect of the oestrogens was lower. Whereas the H2O2 generation was not changed by E2, enhanced by E2V, but diminished by EE2 in all age groups, CL(LUC) and CL(LUM) were inhibited in the order of E2 < E2V < EE2. Also after subchronical treatment of the rats the antioxidative action of the oestrogens was evident, microsomal LPO was inhibited in the order of E2 < E2V < EE2. All oestrogens inhibited ethylmorphine N-demethylation. But enhanced H2O2 generation and increased CL(LUC) also indicate a formation of reactive oxygen species by these oestrogens. Obviously in vitro the antioxidative phenolic structure of the oestrogens dominates, whereas after in vivo administration the dose- and age-dependent biotransformation produces prooxidative in addition to antioxidative structures.     

Metabolism of lipid peroxides during chemical carcinogenesis

The content of lecithins and cephalins and the activity of enzymic and nonenzymic systems of phospholipid peroxidation in the microsomes and mitochondria of the rat liver were sharply changed after injection of 3,4-benzpyrene. Significant changes take place in the content of lipid peroxides and activity of enzymes utilizing lipid peroxides (glutathione peroxidase, glutathione reductase) in the rat liver during carcinogenesis. Accumulation of lipid peroxides in the rat liver during carcinogenesis was shown to be connected with disturbances of balance between the systems generating and detoxicating lipid peroxides. The absence of lipid peroxides in the tumors can be attributed to high activity of protective enzyme systems and it reflects adaptive mechanisms aimed at maintaining a high background of proliferating cells in the tumor.Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow; Rostov Cancer Research Institute, Ministry of Health of the RSFSR. (Presented by Academician of the Academy of Medical Sciences of the USSR E. M. Tareev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 3, pp. 270–273, March, 1979.     

In vitro effects of calcium channel blockers and beta-adrenergic blocking agents on microsomal lipid perocidation and cytochrome p-450 content.

The effects of the calcium channel blockers (CCB) nifedipine (N), verapamil (V) and diltiazem (D) and the beta adrenergic blocking agents (BAB) propranolol (P) and atenolol (A) administered alone or in combination on lipid peroxidation (LPO) and cytochrome p-450 content were studied in rat liver microsomes. The drugs were tested in concentrations of 1 mM. V, A and P alone significantly decreased TBARS formed after in vitro stimulation of LPO by Fe2+ and ascorbate, whereas no antioxidant effect was found for N and D. A correlation between the antioxidant capacity of the drugs and their ability to protect cytochrome p-450 after in vitro stimulation of LPO was observed except for propranolol. Moreover, propranolol abolished cytochrome p-450 protecting effect of verapamil when administered together. A direct, LPO-independent decreasing effect on cytochrome p-450 was observed upon in vitro incubation of microsomes with propranolol. The results are discussed in terms of LPO-dependent degradation of cytochrome p-450, formation of propranolol reactive metabolites and propranolol-dependent changes in cytochrome lipid environment.     

Evaluation of possible pro- or antioxidative properties and of the interaction capacity with the microsomal cytochrome P450 system of different NMDA-receptor ligands and of taurine in vitro

In the first part of the study possible additional antioxidative effects of various N-methyl-D-aspartate (NMDA)-receptor antagonists, some of which are used in the treatment of Parkinson's or Alzheimer's disease or as narcotic (dizocilpine, ketamine, budipine, memantine, amantadine, AP-5) were investigated in vitro in comparison to the respective agonists (NMDA, glutamate, aspartate, glycine) and the putative antioxidative amino acid taurine. For this purpose, effects on cytochrome P450 (P450) mediated oxidase functions in rat liver and brain microsomes were examined by measuring the influence on stimulated lipid peroxidation (LPO), H₂O₂ production, and lucigenin and luminol amplified chemiluminescence. Additionally, effects on rat whole blood chemiluminescence (WB-CL) were assessed.

In the second part of the study the influence of the substances on P450 mediated monooxygenase functions in rat liver 9000 g supernatants, as assessed by the model reactions ethoxyresorufin O-deethylation (EROD), ethoxycoumarin O-deethylation (ECOD), and ethylmorphine N-demethylation (EMND), was investigated in order to evaluate possible interactions with the biotransformation of other foreign or endogenous substances.

The non-competitive antagonists dizocilpine, ketamine, budipine and memantine concentration-dependently diminished all oxidase model reactions in both rat liver and brain microsomes. Amantadine was only slightly effective in brain microsomes and on LPO in liver microsomes. No noticeable effect was seen with the competitive antagonist AP-5, with all agonists and with taurine. WB-CL was diminished by all antagonists and by glutamate but not affected by the other agonists and taurine.

Dizocilpine, ketamine, budipine and memantine concentration dependently inhibited EROD, ECOD and EMND, amantadine only EROD and ECOD activity. The other substances were without any effect.

These results demonstrate that only the non-competitive NMDA-receptor antagonists seem to have antioxidative properties. On the other hand, only with the non-competitive antagonists interactions with the P450 system and thus with the biotransformation of other substances are to be expected.     

肾阳虚证患者红细胞LPO、SOD和ATP酶活性的变化

目的 :探讨肾阳虚证患者红细胞LPO、SOD和ATP酶活性的特点及其意义。方法 :观察 19例肾阳虚证患者和 2 1例正常人红细胞LPO、SOD和红细胞膜Na+ K+ ATP酶、Mg2 + ATP酶、Ca2 + ATP酶、Ca2 + Mg2 + ATP酶活性的变化。结果 :与对照组比较 ,肾阳虚证患者红细胞LPO含量升高 (P <0 .0 1) ,红细胞SOD活性降低 (P <0 .0 1) ;红细胞膜Na+ K+ ATP酶活性显著升高 (P <0 .0 1) ,而Mg2 + ATP酶活性变化无显著性差异 ,Ca2 + ATP酶活性升高 (P <0 .0 1) ,Ca2 + Mg2 + ATP酶活性也显著升高 (P <0 .0 1)。结论 :肾阳虚证患者红细胞内脂质过氧化反应增强 ,而抗氧化能力降低 ,红细胞膜Na+ K+ ATP酶、Ca2 + ATP酶和Ca2 + Mg2 + ATP酶活性升高 ;本研究为理解肾阳虚证的病理生理基础提供了初步实验依据     

Immunological, antioxidative, and morphological response in combined treatment of ofloxacin and Lactobacillus fermentum ME-3 probiotic in Salmonella Typhimurium murine model

We aimed to elucidate the immunological (cytokines), biochemical (antioxidative), and patho-morphological responses in the gut and liver evoked by the addition of Lactobacillus fermentum ME-3 to ofloxacin (OFX) treatment in an experimental infection model of Salmonella enterica serovar Typhimurium. After challenge with S. Typhimurium and treatment according to different schemes, either with OFX and/or addition of L. fermentum ME-3, the mice were killed. Blood, liver, spleen, and small intestine samples were plated to detect S. Typhimurium and lactobacilli. Histological slides were prepared from the liver and ileum. The cytokines (IL-10, IFN-γ, and TNF-α), the glutathione peroxidase and reductase, the glutathione ratio, and the lipid peroxides (LPO) in mucosa of the small intestine and liver were estimated. The addition of L. fermentum ME-3 to OFX increased the eradication of S. Typhimurium from tested sites because of antagonistic and antioxidative properties, reduced the presence of typhoid nodules in the liver, and decreased the values of LPO. The immunological response included the reduction of pro-inflammatory cytokines interferon-γ and tumour necrosis factor-α and the increase in anti-inflammatory cytokine interleukin-10 in the livers of mice without typhoid nodules.     

补充VA、VE对梭曼中毒大鼠体内抗氧化能力影响的初探

目的 研究梭曼对急性中毒大鼠的自由基损伤作用,探讨维生素A、E的抗氧化作用。方法 雄性大鼠,随机分为对照组、阳性组、VA组、VE组。灌胃10d,第11d除阴性组外其余各组大鼠均皮下注射0．9LD50梭曼,2h后取样,测定各组全血和肝组织的谷胱甘肽过氧化物酶（GSH－Px)、过氧化氢酶（CAT）、VE和总抗氧化力（T－AOC）。结果 梭曼中毒2h后,GSH－Px活性、T－AOC水平、VE含量降低。维生素A、E均有效的抑制其变化。结论 梭曼对大鼠有自由基损伤作用,维生素A、E对梭曼中毒大鼠过氧化损伤具有保护作用,提示维生素A、E对梭曼中毒有预防作用。     

胸腺在大鼠肝脏自由基代谢中的作用

本文以成年去胸腺大鼠为模型,旨在观察胸腺对肝脏自由基代谢的影响。实验结果表明,雌性去胸腺大鼠和雌、雄性老年大鼠肝匀浆及肝微粒体过氧化脂质增多,肝匀浆超氧化物歧化酶活力和还原型谷胱甘肽含量降低,但雄性去胸腺大鼠上述指标与对照组相比无明显变化。     

Antioxidant Status of Rats Receiving Lycopene in Different Doses

Oral treatment with lycopene (per os) in doses of 10 or 50 mg/kg for 2 weeks led to accumulation of lycopene in the liver, liver microsomes, and blood plasma, increased total plasma antioxidant activity, inhibited LPO in the liver, and decreased solubilization of lysosomal enzymes. Lycopene had no effect on ex vivo resistance of liver microsomes to LPO and activities of antioxidant enzymes in the liver.     

Free radicals in chronic pathology of the liver

The review deals with the role of free radicals (FR) in chronic liver pathology. Oxygen FR, on the one hand, have the protective function connected with the activation of phagocytes, on the other hand, they exert a toxic effect damaging the cell. Lipid peroxidation (LPO) plays an important role in the cytotoxic effect of FR. The disturbance of the balance between oxidative reactions and protective mechanisms is likely to be the starting point in the development of "FR-pathology". The proves of the FR participation in the hepatobiliary pathology are given. A high level of LPO and the decrease of the antioxidative enzymes activity in chronic liver diseases are shown indicating the initiation of the lipid autooxidation reaction. The activation of LPO is most demonstrative in the active alcoholic process.     

The protective effects and genetic pathways of thorn grape seeds oil against high glucose-induced apoptosis in pancreatic β-cells

Background

Chemicals of herbal products may cause unexpected toxicity or adverse effect by the potential for alteration of the activity of CYP450 when co-administered with other drugs. Eleutherococcus senticosus (ES), has been widely used as a traditional herbal medicine and popular herbal dietary supplements, and often co-administered with many other drugs. The main bioactive constituents of ES were considered to be eleutherosides including eleutheroside B (EB) and eleutheroside E (EE). This study was to investigate the effects of EB and EE on CYP2C9, CYP2D6, CYP2E1 and CYP3A4 in rat liver microsomes in vitro.

Method

Probe drugs of tolbutamide (TB), dextromethorphan (DM), chlorzoxazone (CLZ) and testosterone (TS) as well as eleutherosides of different concentrations were added to incubation systems of rat liver microsomes in vitro. After incubation, validated HPLC methods were used to quantify relevant metabolites.

Results

The results suggested that EB and EE exhibited weak inhibition against the activity of CYP2C9 and CYP2E1, but no effects on CYP2D6 and CYP3A4 activity. The IC₅₀ values for EB and EE were calculated to be 193.20 μM and 188.36 μM for CYP2E1, 595.66 μM and 261.82 μM for CYP2C9, respectively. Kinetic analysis showed that inhibitions of CYP2E1 by EB and EE were best fit to mixed-type with Ki value of 183.95 μM and 171.63 μM, respectively.

Conclusions

These results indicate that EB and EE may inhibit the metabolism of drugs metabolized via CYP2C9 and CYP2E1, and have the potential to increase the toxicity of the drugs.     

Antioxidant effect of short-term hormonal treatment in postmenopausal women

OBJECTIVES: Recent studies have shown that estrogens alone or in association with progestins can exert an antioxidant effect on Low-Density Lipoprotein (LDL) and lipids of platelet membranes. It has been demonstrated that the oxidative modification of LDLs also involving the formation of lipid peroxides, exerts several biological effects that may contribute to the onset and progression of cardiovascular diseases. Therefore, the aim of our study was to evaluate the effect of short-term treatment with oral estrogens alone and estrogens plus progestin on endogenous and copper-induced serum levels of lipid peroxides in postmenopausal women. METHODS: Thirty-nine postmenopausal women were randomly divided into three groups: group I was treated with oral conjugated equine estrogens (CEE) for 21 days; group II received oral CEE for 21 days and, after 14 days of this treatment, 5 mg/day of medrogestone was added for 7 days; group III did not receive any therapy (controls). Endogenous and copper-induced serum levels of lipid peroxides were determined before and after 21 days of treatment in the two treated groups and in the control group. RESULTS: The serum endogenous levels of lipid peroxides in postmenopausal women did not change after short-term treatment with hormone replacement therapy. Moreover, copper-induced serum levels of lipid peroxides significantly decreased after therapy in both groups I and II. CONCLUSIONS: Our data show that hormone replacement therapy (HRT) inhibits lipid peroxidation and may play a role in preventing cardiovascular diseases.     

白细胞及其释放的氧自由基在活化补体导致急性肺损伤中的作用

作首用白细胞抗体,观察了酵母多糖活化的血浆(ZAP)分别对白细胞数正常(n=7)和减少(n=7)的山羊肺淋巴中脂质过氧化物(LPO)及超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-px)的影响,及其与肺损伤的关系。ZAP导致肺淋巴LPO含量由2.26±0.03nmol/ml增至3.26±0.09nmol/ml,SOD活性由258.10±4.53u/ml升至354.07±13.27u/ml,同时引起通透性肺损伤。而GSH-px活性则由189.34±4.16u/ml降为184.59±5.54u/ml。白细胞减少组山羊肺损伤程度较轻,LPO量增加不明显。实验结果提示:白细胞及其产生的自由基参与ZAP肺损伤过程。     

Lipid peroxides, antiperoxidase and the progressive course of experimental atherosclerosis]

Rabbits were fed on cholesterol-rich (CHO) diet first for 60 days, and serum cholesterol, serum lipid peroxides (LPO) and superoxide dismutase (SOD) activities were measured at various periods after the withdrawal of the CHO-rich diet. The correlation of the above figures and the initiation, progression and regression of atherosclerotic lesion were studied. Results showed that: (1) when rabbits were fed on a CHO-rich diet for 60 days, the serum CHO and LPO increased significantly. Anyhow, the SOD activity was only slightly elevated when tiny atherosclerotic lesions developed in the aortae. (2) right after withdrawal of the CHO diet, serum CHO decreased significantly, but atherosclerotic lesion became even more severe than before. (3) after withdrawal of the CHO diet for 120 days, serum CHO, LPO content and SOD activity all returned to normal range and the atheromatous lesion became less severe except calcification and fibrosis developed in certain areas.     

Fibrates and their newly synthesized glycinate or glycinate-methylester derivatives: comparison of the interactions with liver cytochrome P450 dependent monooxygenase- and oxidase-functions in vitro.

Different fibrates (bezafibrate, ciprofibrate, clofibrate, fenofibrate, gemfibrozil) were investigated in comparison with their newly synthesized glycinate and glycinate-methylester derivatives. Interactions with the cytochrome P450 (CYP) system were studied by assessing binding to CYP and effects on CYP mediated monooxygenase functions in rat liver 9000 g supernatants, as measured by six model reactions for different CYP isoforms (ethoxyresorufin O-deethylation, ethoxycoumarin O-deethylation, pentoxyresorufin O-depentylation, p-nitrophenol-hydroxylation, ethylmorphine N-demethylation, lauric acid 11- or 12-hydroxylation). Possible prooxidant or antioxidant properties were investigated by the stimulated lipid peroxidation, hydrogen peroxide production, and lucigenin and luminol amplified chemiluminescence using rat liver microsomes. Additionally, the influence on luminol amplified rat whole blood chemiluminescence was examined.

All substances tested displayed binding to CYP. Effects on the monooxygenase model reactions were in general more distinct with the glycinates than with the parent compounds and most pronounced with the glycinate-methylester derivatives. The slightest effects on all model reactions were seen with clofibrate and its derivatives.

On the whole, low antioxidative rather than prooxidative effects were observed. In general and with most model reactions, the antioxidative capacity of the glycinate and glycinate-methylester derivatives slightly exceeded that of the respective parent compounds.

Summarizing the results it can be concluded that with respect to possible interactions with the CYP system in vivo and thus with the biotransformation of other concomitantly administered compounds no advantages of the glycinate or glycinate methylester derivatives over their parent fibrates are to be expected. Only the antioxidative capacity of the derivatives was somewhat higher than that of the parent substances, though most probably only of minor therapeutical relevance.     

Effects of ionol and alpha-tocopherol on lipid peroxidation in the liver of dogs with acute pancreatitis

We studied effects of natural (alpha-tocopherol) and synthetic (ionol) antioxidants on lipid peroxidation (LPO) in the liver of dogs with acute experimental pancreatitis (AEP). In the first three days of experiment formation of DK was more strongly inhibited by alpha-tocopherol but after day 6--by ionol. Alpha-tocopherol more effectively inhibits formation of intermolecular connections of lipid peroxides at transition of DK in intermediate (MDA) and end-products of POL. Ionol shows this effect on hour 8-24 and day 6-20. Fat-soluble antioxidants act directly in the lipid bilayer of plasma and cell membranes by interacting with membrane lipophilic components.     

丹参对急性心肌缺血时脂质过氧化的影响

本实验以结扎家兔冠脉左室支造成在体急性心肌缺血模型,以硫代巴比妥酸荧光法测定心肌组织脂质过氧化物含量,探讨心肌脂质过氧化情况及其与心电图ST段改变的关系,并以丹参注射液为心肌保护因素,观察脂质过氧化物、心电图ST段的变化,探讨丹参对心肌的保护作用。实验结果表明:结扎冠脉左室支40分钟时,缺血区心肌脂质过氧化物含量比对照组增加2.4倍(P<0.01),缺血区脂质过氧化物含量与心电图ST段抬高程度呈正相关(r=0.822,P<0.025)。预先静脉注射丹参注射液,使缺血区心肌脂质过氧化物含量较缺血组缺血区降低47.9%(P<0.02).并使冠脉左室支结扎后2至5分钟的心电图ST段抬高程度降低44.8～47.0%(P<0.05)。     

Behavioral and neuroanatomical effects of prenatal, postnatal, or combined exposure to ethanol in weanling rats

Separate and combined effects of prenatal and postnatal exposure to ethanol on activity, emotionality, learning, and hippocampal neuroanatomy were examined in infant rats. Neonatal rats from mothers that were fed either a liquid ethanol (E) or control (C) diet on Gestational Days (G) 1-21 were artificially reared during Postnatal Days (P) 4-12 on either 3% ethanol (E) or isocaloric maltose/dextrin (C) in a milk formula. Pups in these treatment groups (EE, EC, CE, and CC) were tested for activity and emotionally in an open field on P19, for acquisition and extinction of an appetitive, straight runaway task on P20-P21, and for the effects of ethanol treatments on alterations in hippocampal neuroanatomy on P21. Differences in activity and emotionally were slight. Ethanol affected both the partial reinforcement acquisition effect and the partial reinforcement extinction effect. Hippocampal cell density (compared with Group CC) showed a 12% reduction in CA1 pyramidal cells and an 11% reduction in mature granule cells in Groups EC and EE; the CA4 area (compared with Group CC) was significantly larger after postnatal exposure (Groups CE and EE). Significant positive correlations were found between rate of extinction after partial reinforcement (PRF) training and CA1 pyramidal cell density in Groups CC and CE. A significant negative correlation was found between extinction rate after PRF training and CA4 area in Group EE.     

益气通络丹对心肌缺血再灌注损伤脂质过氧化及纤溶活性的影响

本文观察益气通络丹对家兔心肌缺血再灌注损伤时丙二醛总超氧化物歧化酶，铜锌超氧化物歧化酶，组织型纤溶酶原激活物，纤溶酶原激活物的抑制物活性及心肌细胞超微结构的影响。     

Effects on antioxidant status of liver following atrazine exposure and its attenuation by vitamin E

In the present investigation, the effect of atrazine on antioxidant enzymes and body weight was studied in male Wistar rats. Atrazine (300 mg/kg bw) was administered by gavage for 7, 14 and 21 days. A significant increase in hepatic lipid peroxidation (LPO) was observed following atrazine administration. Vitamin E treatment (100 mg/kg bw), on the otherhand, attenuated atrazine-induced LPO in liver. In addition, vitamin E treatment restored the GSH content and glucose-6-phosophate dehydrogenase activity that was found to be lowered after atrazine administration. The activities of antioxidant enzymes: superoxide dismutase, catalase, glutathione peroxidase and glutathione-s-transferase were significantly increased following atrazine administration and vitamin E treatment could restore these activities. In conclusion, the results of the study demonstrate that atrazine induces oxidative stress in terms of enhanced lipid peroxidation. However, vitamin E treatment ameliorated the effects of atrazine suggesting it as potential antioxidant against atrazine-induced oxidative stress.