Phospholipidomic Analysis Reveals Changes in Sphingomyelin and Lysophosphatidylcholine Profiles in Plasma from Patients with Neuroborreliosis

In recent years, the number of patients suffering from Lyme Disease (LD) has significantly increased. The most dangerous manifestation of LD is neuroborreliosis associated with invasion of the central nervous system by Borrelia burgdorferi. Phospholipids (PL) and their metabolites are involved in inflammation, which plays a dominant, but still unclear, role in the pathogenesis of neuroborreliosis. We analyzed the plasma PL profiles of neuroborreliosis patients (n = 8) and healthy volunteers (n = 8) using a lipidomic approach. Significant increases in the lysophosphatidylcholines LysoPtdCho 16:0 and LysoPtdCho 18:2 were observed. The plasma of neuroborreliosis patients appeared to have an increased relative abundance of sphingomyelin CerPCho d18:1/24:1 and a decrease in CerPCho d18:0/18:0. Principal components analysis of the relative abundances of all PL class species distinguished between neuroborreliosis patients and healthy subjects. This is the first report comparing PL classes and their molecular species in neuroborreliosis patients and healthy subjects.

The redox status of human breast cancer cell lines (MCF-7 and MDA-MB231) treated with novel dinuclear berenil-platinum(II) complexes

This study compared the effects of cisplatinum and novel berenil-platinum(ll) complexes on the redox status of breast cancer cells that were estrogen receptor-positive (MCF-7) or estrogen receptor-negative (MDA-MB231). Both cell lines were treated with cisplatinum or the following berenil-platinum(ll) complexes: Pt2(isopropylamine)4(berenil)2, Pt2(piperidine)4(berenil)2, Pt2(2-picoline)4(berenil)2, Pt2(3-picoline)4(berenil)2, and Pt2(4-picoline)4(berenil)2. Changes in levels of reactive oxygen species, levels and activities of antioxidants, and lipid peroxidation products levels were measured. All investigated compounds enhanced ROS generation, reduced the activity of antioxidant enzymes (e.g., glutathione peroxidase and glutathione reductase), and decreased levels of small-molecule antioxidants (GSH, vitamins E and A). Such conditions are conducive to generating oxidative stress and phospholipids peroxidation. Cellular phospholipids in MCF-7 cells were most sensitive to the Pt2(isopropylamine)4(berenil)2 complex, whereas MDA-MB231 cells were not particularly sensitive to any berenil-platinum(ll) complex. These findings will facilitate future anticancer drug design strategy for breast cancer pharmacotherapy.

Age-dependent changes in the proteolytic-antiproteolytic balance after alcohol and black tea consumption

Aging is accompanied by changes in the redox balance that is additionally modified by alcohol. Ethanol metabolism is connected with generation of free radicals which can damage cell components especially when antioxidant mechanisms are not able to neutralize them. In connection with the necessity of prevention against oxidative consequences, natural antioxidants are looked for. A natural and commonly used component of the diets with antioxidant properties are teas, especially the black tea. This study provides evidence of the role of black tea in the protection of rat plasma proteins and lipids against oxidative stress caused by aging and ethanol intoxication. For 5 weeks, the rats (2-, 12-, and 24-months old) used for the experiment received a black tea beverage (3 g/l) without or with alcohol (given for 4 weeks). The decrease in antioxidant abilities determined as total antioxidant status during aging and ethanol intoxication resulted in enhanced lipid and protein oxidation (determined as malondialdehyde, carbonyl groups, dityrosine, tryptophan and sulfhydryl groups level). In consequence the decrease in anti-proteases (alpha-1-antitrypsin, alpha-2-macroglobulin) activity and the increase in proteases (elastase and cathepsin G) activity were observed. Black tea protected the plasma antioxidants and prevented oxidative modifications of lipid and protein observed during aging as well as ethanol intoxication. The results indicate that a shift into plasma proteolytic activity results from a decrease in antioxidant abilities, so the use of black tea appears to be beneficial in reducing oxidative stress caused by ethanol and/or aging.

Lipid peroxidation products as potential bioindicators of Lyme arthritis

Lipid peroxidation products, malondialdehyde (MDA), 4-hydroxynonenal (4-HNE) and [Formula: see text], were determined in the plasma and urine of patients with Lyme arthritis and healthy people. The group consisted of 19 patients with Lyme arthritis (mean age 47 years) and the control group consisted of 16 healthy individuals (mean age 38 years). Diagnosis of Lyme disease was confirmed by epidemiological anamnesis, clinical manifestation of arthritis and serological examinations. Lipid peroxidation was estimated by the measurement of aldehydes (MDA and 4-HNE, determined by high-performance liquid chromatography [HPLC]) and prostaglandin derivatives (8 - isoPGF(2a), determined by liquid chromatography/mass spectrometry [LC/MS]). MDA and 4-HNE levels were increased about 2-4-fold in the plasma, while in the urine, the increases were about 2-fold. More significant increases were noted for the 8 - isoPGF(2a) total plasma level, which was enhanced over 4-fold, and for the urine 8 - isoPGF(2a) level, which was increased over 8-fold. The 8 - isoPGF(2a) total plasma level consists of free and esterified form. During infection, the ratio of free to esterified form is significantly smaller compared to healthy people. The ratio of free to esterified form of 8 - isoPGF(2a) may be a useful indicator of Lyme arthritis. Moreover, the complementarities of three lipid peroxidation product levels may be helpful in the diagnosis of Lyme arthritis.

The comparison of effect of catechins and green tea extract on oxidative modification of LDL in vitro

PURPOSE

Green tea due to its content of catechins reveals strong antioxidative activity, which is manifested among others by its ability to inhibit free radical generation, scavenge free radicals as well as chelate transition metal ions that catalyse free radical reactions. The influence of green tea extract, epicatechin (EC), epicatechin galate (ECG) as well as epigallocatechin galate (EGCG) on oxidative modifications of LDL of human blood serum has been examined in the present study.

MATERIALS AND METHODS

This influence has been evaluated by measurement of the concentration of first products of lipid peroxidation--conjugated dienes and lipid hydroperoxides as well as by determining tryptophan and dityrosine content-- the markers of protein oxidative modification.

RESULTS

Catechins and green tea abilities to protect lipophilic antioxidant--alpha-tocopherol against oxidation have been also examined. The results reveal that peroxidation of LDL is markedly prevented by green tea extract and in a slightly weaker way by catechins (EGCG in particular), which is manifested by a decrease in concentration of conjugated dienes, lipid hydroperoxides, MDA, dityrosine and by an increase in tryptophan content. Both green tea as well as catechins (EGCG in particular) have been also revealed to prevent decrease in concentration of alpha-tocopherol in oxidating conditions.

CONCLUSIONS

It can be assumed that green tea and to a lesser degree catechins, protecting the basic antioxidant of LDL-alpha-tocopherol, prevent oxidative modification of LDL.

Antioxidant potential of rat liver in experimental infection with Fasciola hepatica

The aim of this paper is to assess the antioxidant properties of rat liver in the course of acute and chronic fasciolosis. Wistar rats were infected per os with 30 metacercariae of Fasciola hepatica. Liver activities of antioxidant enzymes and concentrations of non-enzymatic antioxidants were determined at 4, 7, and 10 weeks post-infection. Activities of superoxide dismutase (Cu,Zn-SOD), glutathione peroxidase (GSH-Px), and glutathione reductase (GSSG-R) were decreased, catalase (CAT) activity was increased and non-enzymatic antioxidant concentrations (reduced glutathione, vitamins C, E and A) were reduced simultaneously with enhancement of lipid peroxidation processes as evidenced by increased levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Changes in the antioxidant abilities of the liver and in the phospholipid structure of the cell membrane were accompanied by rising activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as markers of liver damage.

Antioxidative properties of black tea

BACKGROUND

Black tea, obtained by tea leaves fermentation, is an oxidized product and contains mainly multimeric polyphenols, whose biological activity is not well documented. This paper reviews the available literature on the effects of black tea on health with a focus on its antioxidative activity.

METHODS

A review of the different issues and studies relating to composition, manufacturing, and antioxidative effects of black tea and its components in vitro as well as in vivo is presented.

RESULTS

It is generally believed that polyphenols such as theaflavins and thearubigins as well as catechins as major constituents of black tea are mainly responsible for antioxidant actions. Antioxidative properties of black tea are manifested by its ability to inhibit free radical generation, scavenge free radicals, and chelate transition metal ions. Black tea, as well as individual theaflavins, can influence activation of transcription factors such as NFkappaB or AP-1. Theaflavins have been also proved to inhibit the activity of prooxidative enzymes such as xanthine oxidase or nitric oxide synthase.

CONCLUSIONS

Black tea consumed throughout the world is believed to be not only a popular beverage but also an antioxidative agent available in everyday life.

Influence of green tea on surface charge density and phospholipids composition of erythrocytes membrane in ethanol intoxicated rats

Ethanol is oxidized to acetaldehyde and then to acetic acid and these processes are accompanied by free radical generation. This paper reports the effect of green tea on electric charge and phospholipids composition of erythrocytes membrane from rats intoxicated with ethanol. Electrophoresis technique and HPLC have been applied to above-mentioned studies. Ethanol administration caused increase in erythrocyte membrane surface charge density and phospholipid composition. Ingestion of green tea with ethanol partially prevented changes in structure and function of membrane caused by chronic ethanol intoxication.

Antioxidant properties of black tea in alcohol intoxication

Food ingredients such as alcohol may modify cellular redox state. Ethanol metabolism is accompanied by generation of free radicals that can damage cell components especially when antioxidant mechanisms are no able to neutralize them. However black tea is a source of polyphenol antioxidants that may enhance cellular antioxidant abilities. The aim of this study was to investigate the effect of black tea on antioxidant abilities of the liver, blood serum and brain of 12-months old rats sub-chronically (for 28 days) intoxicated with ethanol. Administration of black tea alone caused increase in the activity and concentration of antioxidant parameters more extensively in the liver and serum than in the brain. Alcohol caused decrease in the liver glutathione peroxidase and reductase and catalase activity but increase in activity of superoxide dismutase. Moreover, decrease in the level of non-enzymatic antioxidants, such as reduced glutathione, vitamin C, A and E and beta-carotene was observed. The activity of serum glutathione peroxidase and reductase decreased while superoxide dismutase activity was not changed. The level of non-enzymatic antioxidants in serum was also decreased. However brain activity/level of all examined antioxidants enzymatic as well as non-enzymatic was decreased after ethanol intoxication. Black tea considerably prevented antioxidant parameters against changes caused by ethanol. These results indicate beneficial antioxidant effect of black tea regarding all examined tissues, but especially the liver.

Protein Z and vitamin K in kidney disease

PURPOSE

Disturbances in hemostasis are common complications of kidney diseases. Both bleeding diathesis and thromboembolism may complicate the course of chronic uremia. As far as we know, there is a limited data about protein Z in kidney disease.

MATERIAL AND METHODS

The aim of our work was to examine plasma protein Z and vitamin K concentrations in nephrotic syndrome (n = 34), glomerulonephritis (n = 48), kidney transplant recipients (n = 80), peritoneally dialyzed patients (n = 42) and in the healthy volunteers (n = 27).

RESULTS

Vitamin K was significantly lower in nephrotic syndrome when compared to non-nephrotic patients, CAPD and healthy volunteers (p < 0.05). Protein Z was the highest in CAPD and kidney transplant recipients when compared to any other group. In nephrotic syndrome protein Z was significantly lower when compared to the healthy volunteers, but it did not differ significantly between two groups of patients with chronic renal failure (with and without nephrotic syndrome). Protein Z correlated only with fibrinogen in CAPD, glomerulonephritis and nephrotic patients. Vitamin K correlated with age and albumin in patients with glomerulonephritis, nephrotic syndrome as well as with albumin in CAPD.

CONCLUSIONS

Alterations in protein Z might contribute to the enhanced risk of thromboembolic complications in nephrotic syndrome, CAPD and Tx via different and unknown mechanisms. This phenomenon seems to be unrelated to vitamin K status in these patients.

Release of hydroxyl ions from calcium hydroxide preparations used in endodontic treatment

PURPOSE

The purpose of our study was to compare the in vitro release of hydroxyl ions from several calcium hydroxide preparations used in endodontic treatment.

MATERIAL AND METHODS

Equal quantities of the materials--nonsetting (pure calcium hydroxide, Biopulp, Calcicure), setting--canal sealers (Sealapex, Apexit) and points were placed in dialysis tubes which were then immersed in deionized water. The release of hydroxyl ions from the preparations was measured by the median pH of the deionized water used for dialysis, by means of a pH-meter. The results of our study were analyzed by means of Tukey's reasonable correlation. Significance difference (one-way variance analysis ANOVA) and Pearson's linear correlation coefficient (r2).

RESULTS

Nonsetting preparations of calcium hydroxide have a significantly higher capability of hydroxyl ions release in comparison with sealers and points, irrespective of time (p < 0.05). Sealapex and "plus" points released hydroxyl ions to a much greater extent than both Apexit and "regular" points at most periods of the experiment (p < 0.05). Apexit released significantly more of hydroxyl ions than "regular" points, and Sealapex more than "plus" points in the later periods of the experiment (p < 0.05). The pH values of dialysis samples of all materials correlated positively with time and the pH. Almost all materials reached a maximum on the 8-th day of the experiment.

CONCLUSIONS

To achieve maximum concentration of hydroxyl ions in tissues: for temporary root fillings nonsetting preparations of calcium hydroxide should be chosen rather than points and they should be placed for at least one week, for permanent root fillings it is more recommended to use Sealapex than Apexit as a sealer.

Green tea as a potent antioxidant in alcohol intoxication

Ethanol oxidation to acetaldehyde and next to acetate is accompanied by free radical generation. Free radicals can affect cell integrity when antioxidant mechanisms are no longer able to cope with the free radical generation observed in ethanol intoxication. Natural antioxidants are particularly useful in such a situation. The present study was designed to investigate the efficacy of green tea as a source of water-soluble antioxidants (catechins) on the liver and blood serum antioxidative potential of rats chronically (28 days) intoxicated with ethanol. Alcohol caused a decrease in liver superoxide dismutase, glutathione peroxidase and catalase activities and an increase in activity of glutathione reductase. Moreover, a decrease in the level of reduced glutathione, ascorbic acid, vitamins A and E and beta-carotene were observed. The activity of serum glutathione peroxidase decreased while glutathione reductase activity increased. The level of serum non-enzymatic antioxidants was also decreased in the liver. Alcohol administration caused an increase in the liver and serum lipid peroxidation products, measured as thiobarbituric acid-reactive substances. However, green tea prevents the changes observed after ethanol intoxication. Green tea also protects membrane phospholipids from enhanced peroxidation. These results indicate a beneficial effect of green tea in alcohol intoxication.

Cancer procoagulant as a marker in monitoring the therapy in cases of oesophageal, stomach and colorectal cancer

Cancer procoagulant activity in the blood serum of patients with oesophagal, gastric and colorectal cancer was evaluated before and after the tumour removal. Cancer procoagulant activity was significantly higher before the operation in comparison to the control group and was reduced after a total operative procedure, whereas it was kept on a high level after a non-radical procedure or in cases of metastases. Examination results point to the possibility of using the evaluation of cancer procoagulant activity in monitoring the course of treatment of patients with oesophagal, gastric and colorectal cancer.

[Melatonin as an antioxidant]

This review describes the structure and properties of melatonin. The interaction of melatonin with reactive oxygen species and its protective action in relation to DNA, lipids and proteins are presented. The effect of melatonin on antioxidant and prooxidant enzymes is discussed, too.

Protective effect of green tea against lipid peroxidation in the rat liver, blood serum and the brain

This paper reports data on the effect of green tea on the lipid peroxidation products formation and parameters of antioxidative system of the liver, blood serum and central nervous tissue of healthy young rats drinking green tea for five weeks. The rats were permitted free access to solubilized extract of green tea. Bioactive ingredients of green tea extract caused in the liver an increase in the activity of glutathione peroxidase and glutathione reductase and in the content of reduced glutathione as well as marked decrease in lipid hydroperoxides (LOOH), 4-hydroksynonenal (4-HNE) and malondialdehyde (MDA). The concentration of vitamin A increased by about 40%. Minor changes in the measured parameters were observed in the blood serum. GSH content increased slightly, whereas the index of the total antioxidant status increased significantly. In contrast, the lipid peroxidation products, particularly MDA was significantly diminished. In the central nervous tissue the activity of superoxide dismutase and glutathione peroxidase decreased while the activity od glutathione reductase and catalase increased after drinking green tea. Moreover the level of LOOH, 4-HNE and MDA significantly decreased. The use of green tea extract appeared to be beneficial to rats in reducing lipid peroxidation products. These results support and substantiate traditional consumption of green tea as protection against lipid peroxidation in the liver, blood serum, and central nervous tissue.

Ethanol and N-acetylcysteine influence on the development of liver changes in experimental methanol intoxication

The evaluation of ethanol and N-Acetylcysteine (NAC) influence on histopathological changes in rat liver intoxicated with 3 g of methanol/kg b.w. was conducted, based on morphological examinations in light and electron microscope. The rats received intragastrically 3.0 g of methanol/kg b.w. as a 50% solution, 10% ethanol for 24 hours before methanol and next 48 hours after methanol ingestion and NAC (150 mg/kg b.w.) after 15 min. methanol administrated. The results indicate that methanol intoxication causes pronounced morphological changes in the examined organ. Ethanol administered to methanol-intoxicated rats caused intensification of certain parameters of hepatocytes morphological damage. A simultaneous administration of methanol and NAC resulted in a lower degree of parenchymal damage.

The influence of green tea on the activity of proteases and their inhibitors in plasma of rats after ethanol treatment

Ethanol oxidation in the liver is accompanied by formation of acetaldehyde and free radicals. These compounds can react with biologically active proteins, including proteolytic enzymes and their inhibitors. The aim of this paper was to determine the influence of green tea on the activity of cathepsin G and elastase and their inhibitors such as alpha-1-antitrypsin and alpha-2-macroglobulin, total antioxidant status and lipid peroxidation in plasma of young rats chronically intoxication with ethanol. The activity of cathepsin G and elastase was increased, while the activity of their inhibitors was reduced after ethanol treatment. AT the same time, the total antioxidant status was significantly decreased while lipid peroxidation measured as malondialdehyde and 4-hydroxynonenal was significantly increased. Giving green tea to rats did not change the proteases and their inhibitors activity, but significantly increased total antioxidant status and decreased lipid peroxidation. Drinking green tea with ethanol partially prevents the changes observed after ethanol intoxication.

Cathepsin D activity in colorectal cancer

Cathepsin D is one of the main proteolytic enzymes involved in the neoplastic process. The aim of the study was to evaluate the activity of cathepsin D in 36 colorectal adenocarcinomas (of the colon and rectum) at stage pT3 of clinical advancement and histological grade G2. The correlation of cathepsin D activity with the stage of anatomo-clinical advancement and the presence of chosen anatomo-clinical properties of the tumour was also analysed. The activity of cathepsin D was found to be statistically significantly higher both in the neoplastic tissue cytosol and homogenate, compared to the cytosol and homogenate of adjacent healthy tissue. No correlation was noted between the activity of cathepsin D in neoplastic cells and other parameters analysed.

[Changes in intracellular protein degradation during the aging of an organism]

This review describe the influence of free radicals on the protein degradation during aging. The consequences of aging are changes in susceptibility of proteins on the proteases action as well as changes in cell proteolytic systems activity in different organs.

Role of reactive oxygen species (ROS) in patients with erythema migrans, an early manifestation of Lyme borreliosis

BACKGROUND

Lyme borreliosis is a tick-transmitted, chronic, zoogenous disease caused by Borrelia burgdorferi spirochete. The clinical picture of Lyme disease is characterized by the variety of tissue and organ involvement and differing severity of symptoms. One of the pathogenic symptoms of early Lyme disease is a skin lesion called erythema migrans.

MATERIAL AND METHODS

The purpose of our research was to estimate the parameters of the antioxidant system and the concentration of lipid peroxidation products in the plasma of patients with erythema migrans (EM). The parameters measured included the activity levels of superoxide dismutase (SOD) according to Sykes, gluthatione reductase (GSSG-R) according to Mize and Langdon, glutathione peroxidase (GSH-Px) according to Paglia and Valentine; the concentrations of malondialdehyde (MDA) were examined by means of a Bioxytech LPO-586 kit. The total sulphydryl groups (-SH) according to Ellman and reduced glutathione (GSH) were measured using a Bioxytech GSH-400 test in plasma samples collected from 20 patients with EM aged from 19 to 50, taken before (examination 1) and after (examination 2) therapy with amoxycycline. The control group consisted of 8 healthy people.

RESULTS

The results of our examinations prove that beta-lactamase antibiotic therapy brings non-enzymatic antioxidant parameters to control values, though the treatment causes no change in enzymatic antioxidant parameters, resulting in the further activation of free radicals.

CONCLUSIONS

In patients with Erythema migrans, the decreased capability to reduce lipid superoxidants leads to maintaining a high concentration of membrane lipid peroxidation products.

Antioxidant status and lipid peroxidation in colorectal cancer

Colon carcinogenesis is a multistep process where oxygen radicals were found to enhance carcinogenesis at all stages: initiation, promotion, and progression. Since insufficient capacity of protective antioxidant system can result in cancer, the aim of this study was to examine the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and the levels of reduced glutathione, vitamin C, and vitamin E. The lipid peroxidation products were also determined by measuring malondialdehyde and 4-hydroxynonenal levels in colorectal cancer tissue collected from 55 patients. In these cases the activity of superoxide dismutase, glutathione peroxidase, and glutathione reductase was significantly increased while the activity of catalase was significantly decreased in cancer tissue. However, the level of nonenzymatic antioxidant parameters (glutathione, vitamin C, and vitamin E) was significantly decreased in cancer tissue. Further lipid peroxidation was enhanced during cancer development, manifested by a significant increase in malondialdehyde and 4-hydroxynonenal levels. The obtained results indicate significant changes in antioxidant capacity of colorectal cancer tissues, which lead to enhanced action of oxygen radicals, resulting in lipid peroxidation.

[The activity of cathepsin B in colorectal adenocarcinomas]

The aim of the present study was to evaluate the activity of cathepsin B in 36 colorectal adenocarcinomas at stage pT3 of clinical advancement and histological grade G2. A correlation was also analysed of cathepsin B activity with the stage of anatomo-clinical advancement and the presence of chosen anatomo-clinical features of the tumour. Statistically significantly higher activity of cathepsin B was observed both in the cytosol and homogenate of the neoplastic tissue compared to its activity in the cytosol and homogenate of the adjacent unchanged tissue. A tendency was found towards higher cathepsin B activity in homogenate than in cytosol, both in the neoplastic and normal tissue. No correlation was revealed between cathepsin B activity in neoplastic cells and other anatomo-clinical tumour parameters analysed.

[Cancer procoagulant activity in cases of esophageal, stomach and colorectal cancer considering progression degree and histological type of cancer]

The cancer procoagulant activity has been evaluated in homogenates of esophagal, stomach and colorectal cancer tissues and in the blood serum of patients with these neoplasms's. Activity of CP was significantly higher in examined material than in control. The correlation between CP activity and progression degree as well as histological type was affirmed. The higher activity of CP in homogenates as well as in serum was observed in cases with higher degree of clinical progression and smaller activity of this enzyme corresponded with lower degree of the cancer progression. The highest activity of CP was observed in the cases of adenocarcinoma whereas the lowest in cases of squamous cell carcinoma. Higher activity of CP in homogenates of examined tissues correlated with higher activity of this enzyme in the serum. Activity of CP depended on the tissue localisation of the cancer and the highest was in the cases of stomach cancers whereas the lowest was in the cases of esophagal cancer.

Immunohistochemical evaluation of cathepsin D expression in colorectal cancer

Cathepsin D is one of the main proteolytic enzymes contributing to the development of cancer. The aim of the present study was to evaluate the expression of cathepsin D in 48 colorectal adenocarcinomas at pT3 stage of clinical advancement and G2 histologic grade. The correlation between cathepsin D expression, anatomo-clinical advancement and the presence of chosen anatomo-clinical properties of the tumours was also analysed. Formalin-fixed and paraffin-embedded tissues were investigated with anti-cathepsin D antibody. Immunolocalisation of cathepsin D was performed using Labelled Streptavidin Biotin (LSAB) method. A statistical correlation was found between high catepsin D expression in the cells of the main mass of the cancer and low cathepsin D expression in low-differentiated cancer cells which formed nests at the border of cancer invasion. There was no correlation between cathepsin D expression in the cells of colorectal cancer and other anatomo-clinical parameters of the tumours.

N-acetylcysteine or trolox derivative mitigate the toxic effects of methanol on the antioxidant system of rat brain

The effect of two compounds: N-acetylcysteine (NAC) and trolox derivative (U-83836E) on the methanol induced impairment of the antioxidant system of the rat brain was studied in male Wistar rats (approx. 250 g body weight). The animals were divided into six main groups: control group (0.5 ml of physiological saline intragastrically), NAC group (150 mg/kg intraperitoneally-i.p), U-83836E group (10 mg/kg i.p.), methanol group (3 g/kg intragastrically), NAC+methanol and U-83836E+methanol groups. In these particular groups the changes in antioxidant parameters were observed for 6,12,24,48 h and 5 and 7 days. The results proved that the use of methanol and N-acetylcysteine increased the activities of Cu,Zn-superoxide dismutase, glutathione peroxidase and glutathione reductase by about 15,15 and 41%, respectively, in comparison to the group of rats receiving methanol alone. Similarly, the level of GSH increased by about 17%, the concentration of ascorbate by 20%, while the thiobarbituric acid-reactive substances (TBA-rs) diminished to the values as in control group. The use of new antioxidant U8383E and methanol showed less beneficial effect in the measured parameters however, it serves as a better protector for the methanol induced decrease in GSH-content. These data suggest that NAC and U-83836E mitigate the toxic effects of methanol on the antioxidant system of the rat brain.

[Cancer procoagulant (CP): the new biochemical marker in oncologic diagnosis]

This review describes the physicochemical and biological properties of cancer procoagulant (CP). This procoagulant is cysteine protease which directly activates coagulation factor X to factor Xa. CP is found in the tissues and blood of subjects suffering from cancer so its determination could be very useful in diagnostics and prognostics of cancer disease.

Protective effect of N-acetylcysteine on rat liver cell membrane during methanol intoxication

Methanol is oxidized in-vivo to formaldehyde and then to formate, and these processes are accompanied by the generation of free radicals. We have studied the effect of N-acetylcysteine on liver cell membrane from rats intoxicated with methanol (3.0 g kg(-1)). Evaluation of the effect was achieved by several methods. Lipid peroxidation and surface charge density were measured. An ultrastructural study of the liver cells was undertaken. The concentration of marker enzymes of liver damage (alanine aminotransferase and aspartate aminotransferase) in blood serum was measured. Methanol administration caused an increase in lipid peroxidation products (approximately 30%) as well as in surface charge density (approximately 60%). This might have resulted in the membrane liver cell damage visible under electron microscopy and a leak of alanine aminotransferase and aspartate aminotransferase into the blood (increase of approximately 70 and 50%, respectively). Ingestion of N-acetylcysteine with methanol partially prevented these methanol-induced changes. Compared with the control group, lipid peroxidation was increased by approximately 3% and surface charge density by approximately 30%. Alanine aminotransferase and aspartate aminotransferase activity increased by 9 and 8%, respectively, compared with the control group. The results suggested that N-acetylcysteine was an effective antioxidant in methanol intoxication. It may have efficacy in protecting free radical damage to liver cells following methanol intoxication.

Effect of methanol intoxication on free-radical induced protein oxidation

Oxygen free radicals are generated during methanol-induced liver injury, as was shown for ethanol. The effect of methanol intoxication (6 g kg(-1) body wt.) on protein modification in the liver of rats was investigated. Electron spin resonance determination indicated an increase in the free radical signal 6 and 12 h after intoxication. After 7 days of treatment, the contents of malondialdehyde and carbonyl groups in proteins were significantly increased. The level of amino groups and sulphydryl groups and the amount of tryptophan in proteins were decreased, whereas the amount of bi-tyrosine was increased significantly. Changes in protein structure resulted both from free radical action and formaldehyde generation during methanol intoxication.

Gap junctional intercellular communication and carcinogenesis

Intercellular communications are indispensable for the maintenance of homeostasis in the multicellular organisms. Gap-type junctions are one of the most common and perhaps most interesting intercellular connections. Of various communication systems gap junctional intercellular communication is the only means for cells to directly exchange signals. Substantial progress has recently been made in the studies on the role of gap junctions both in experimental and human tumorigenesis. The present study is a review of the potential mechanisms associated with gap junctional cellular communication included in non-genotoxic tumorigenesis.

Activity of lysosomal proteases in the liver and in the plasma from rats intoxicated with methanol

The activity of lysosomal proteolytic enzymes (cathepsin A, B, C, D and E) in cytosol and in the whole homogenate of the liver and in the blood plasma from rats intoxicated with 1.5, 3.0 and 6.0 g methanol/kg b.w. was measured 6, 12 and 24 h and 2, 5 and 7 days after the intoxication. The activity of all proteases was increased in the cytosol from 12 h to 5 days of intoxication, whereas the activity of these enzymes was decreased in the whole liver homogenate during the same time. The magnitude of the decrease in proteolytic activity in the whole homogenate of the liver depended on the amino acid active center of the enzyme. The greatest decrease was observed for sulfhydryl and hydroxyl proteases and smaller one for carboxyl proteases. The proteases activity in the plasma was increased from 12 h to 5 days after methanol intoxication. These results suggest that during methanol intoxication the cellular and lysosomal membranes are impaired and proteases are translocated into the blood. However, changes in proteases activities and proteases distribution within the hepatocytes may lead to disturbances in the catabolism of cell proteins and to destruction of liver cells.

Morphological changes in the liver of rats intoxicated with methanol

On the basis of morphological examinations in light and electron microscope, the evaluation of methanol influence on the liver of rats was conducted. The examination was carried out in the group of 36 rats that were given a single dose of methanol (1.5 g/kg b.w.) into the stomach through a gastric tube. The liver was taken from rats under the ether anaesthesia after 6, 12, and 24 hours as well as after 2, 5, and 7 days of methanol administration. Results showed that methanol intoxication caused visible changes in the examined organ. Only 6 h after intoxication, lobular peripheral hepatocytes presented characteristic features of vacuolar degradation persisting up to 48 h. Since the second day of intoxication, many cells with double nuclei were found more frequently than in controls. Single hepatocytes or small hepatocytic clusters with the features of deliquescent necrosis could be seen after 5 and 7 days of examination. All animals intoxicated with methanol showed distinct weakness of glycogen reaction. The loss of glycogen resources was highest at 24 h after methanol administration. The results indicate, that methanol causes morphological changes in the rat liver and that intensification of these changes depends on the time after intoxication.

Influence of trolox derivative and N-acetylcysteine on surface charge density of erythrocytes in methanol intoxicated rats

Methanol is oxidized in vivo to formaldehyde and then to formate and these processes are accompanied by free radicals generation. This paper reports the effect of antioxidants: trolox derivative (U-83836E) and N-acetylcysteine (NAC) on lipid peroxidation, surface charge density and hematological parameters of erythrocytes from rats intoxicated with methanol (3.0 g/kg body weight). Methanol administration caused increase in erythrocyte lipid peroxidation products and changes in surface charge density. Ingestion of methanol with U-83836E and NAC partially prevented these methanol-induced changes. This suggests that U83836E and NAC act as effective antioxidants and free radicals scavengers. They may have efficacy in protecting free radical damage to erythrocytes following methanol intoxication.

Protective effect of N-acetylcysteine on reduced glutathione, reduced glutathione-related enzymes and lipid peroxidation in methanol intoxication

The primary metabolic appropriation of methanol is oxidation to formaldehyde and then to formate. These processes are accompanied by formation of superoxide anion and hydrogen peroxide. This paper reports data on the effect of N-acetylcysteine (NAC) on reduced glutathione (GSH) and on activity of some GSH-metabolising enzymes in the liver, erythrocytes and serum of rats intoxicated with methanol (3 g/kg b.w.) during 7 days after intoxication. Methanol administration, increasing concentration of the lipid peroxidation products, decreased the liver glutathione-peroxidase and glutathione reductase (GSSG-R) activities, GSH concentration and total antioxidant status (TAS). The use of NAC after methanol ingestion apparently diminished lipid peroxidation, elevated the GSH level in the liver and erythrocytes, and increased activity of GSH-related enzymes in the serum, erythrocytes and in the liver. These results suggest that NAC exerts its protective effect by acting as a precursor for glutathione, the main low molecular antioxidant and as a free radical scavenger.

Formaldehyde-induced modification of hemoglobin in vitro

Formaldehyde is known to react with proteins. The purpose of our experiments was to analyse in vitro the effect of formaldehyde on the physicochemical and biological properties of hemoglobin molecules. The effect of formaldehyde concentration, reaction time, pH and temperature on hemoglobin free amino groups was estimated. The modified hemoglobin was analysed using electrophoretic, potentiometric and spectrophotometric techniques. Reaction between formaldehyde and hemoglobin was accelerated by increasing concentration of formaldehyde and higher temperature. This reaction was most intensive during the first few hours at pH 7.4 so the amount of free amino groups of hemoglobin was significantly diminished by directly mixing formaldehyde with hemoglobin. The modified protein was characterized by the increase in electrophoretic mobility and the decrease in maximum absorption derived from porphyrin rings. Formaldehyde modified hemoglobin was less susceptible to the action of cathepsin D.

Activity of cathepsin G, elastase, and their inhibitors in plasma during methanol intoxication

Methanol oxidation in the liver is accompanied by formation of formaldehyde and free radicals. These compounds can react with biologically active proteins, including proteolytic enzymes and their inhibitors. The activity of cathepsin G and elastase and their inhibitors such as alpha-1-antitrypsin and alpha-2-macroglobulin in plasma of rats given methanol orally in doses of 1.5, 3, and 6 g/kg was investigated for 7 days. The activity of cathepsin G and elastase was increased from 12 h to 5 d, proportionally to methanol dose. At the same time, activity of their inhibitors was reduced. Methanol ingestion in humans caused changes in activities of proteases and their inhibitors with similar direction as in rats. These changes in activity of proteases and their inhibitors produce significant disturbances in proteolytic-antiproteolytic balance after methanol administration.

The effect of pentoxifylline on ultrastructure and antioxidant potential during cyclophosphamide-induced liver injury

The aim of this study was to evaluate the effect of pentoxifylline (PTXF) (30 mg/kg b.w. for 10 days) on the antioxidant potential in the rat liver after single intraperitoneal (i.p.) cyclophosphamide (CP) administration (150 mg/kg b.w.) and to draw a correlation between the morphological changes and biochemical findings. Morphological examinations were based on ultrastructural analysis in the transmission electron microscope. It was found that single i.p. CP administration caused destructive changes, particularly within mitochondria and in the smooth endoplasmic reticulum of hepatocytes. The changes were accompanied by an increase in the MDA (malondialdehyde) level in liver tissue homogenates. The animals receiving PTXF + CP showed no normalization of MDA level, the same damage of the liver as those given CP, and marked statistically significant decrease in the activity of GSH/Px (glutathione peroxidase) compared to CP-receiving animals. No statistically significant differences were revealed in the activity of Cu,Zn-SOD and GSSR (superoxidase dismutase, glutathione reductase) both between control animals and CP- or CP + PTXF-receiving groups, or between CP and CP + PTXF groups.

Role of reperfusion with polyelectrolyte solution and BN 52021 in hemorrhagic shock-induced changes in rat lungs

The aim of this study was to test whether reperfusion with isotonic standard polyelectrolyte solution alone has any influence on the redox balance in the lung during hemorrhagic shock, and whether reperfusion and BN 52021, used together have better protective effect on free radical lung injury. The results showed that reperfusion with electrolyte solution increased solely glutathione reductase activity (GSSG-R), and diminished the activities of Cu,Zn-superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as the content of SH-groups. Thiobarbituric acid reactive substances (TBA-rs) were much more increased in comparison to hemorrhagic shock. After reperfusion with polyelectrolyte solution and the administration of BN 52021, the antioxidant parameters returned to normal values, while TBA-rs slightly decreased.

The comparison of the antioxidant defense potential of brain to liver of rats after methanol ingestion

The antioxidant enzymatic and nonenzymatic potential in the brain of rats given methanol orally was investigated for 7 days consecutively and compared to that one in the liver. Glutathione (GSH) and the activities of superoxide dismutase (Cu, Zn-SOD), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-R) were reduced in the brain after the first 24 h, whereas in the liver these parameters were diminished after 6 h. The brain catalase (CAT) activity was very low and constant in contrast to high and changeable CAT in the liver. At the beginning of intoxication, the activities of Cu, Zn-SOD and CAT in the liver were increased; after 5 days they were restored to normal values while Cu, Zn-SOD diminished gradually in the brain. An early change that occurred 6 h after intoxication was a decrease of ascorbate in the brain and in the liver. The increase in thiobarbituric acid-reactive substances (TBA-rs) in the liver was preceded by their increase in the brain. Our findings indicate decreased antioxidative potential both in the brain and in the liver of rats after methanol ingestion. The regulatory mechanisms of the antioxidant enzymes in the brain of intoxicated rats differ from those ones in the liver.

Ultrastructural evaluation of lysosomes and biochemical changes in cathepsin D distribution in hepatocytes in methanol intoxication

Methanol oxidation is accompanied by free radicals and formaldehyde formation. It is likely to cause damage of lysosomal membranes. Lysosomal ultrastructure under transmission electron microscope and biochemical localization of cathepsin D were estimated after rats intoxication with methanol. The examination was carried out 6, 12 and 24 h and 2.5 and 7 days after intoxication. Ultrastructural examination showed that methanol causes extension of Golgi apparatus cisterns and an increase in a number of lysosomes. From 12 h to 2 days lysosomes were characterized by damage of structure of membrane enclosing lysosomes. During the first days of intoxication activity of cathepsin D decreased in lysosomes and increased in cytosol. These changes may lead to uncontrolled extralysosomal proteolysis in the liver cells and to the onset of liver tissue destruction.

Ultrastructural evaluation of hepatocytes membranes and changes in cytosolic enzymes distribution in methanol intoxication

Acute methanol intoxication causes metabolic and structural disturbances of liver cells. The aim of this paper, therefore, was to evaluate the ultrastructure of liver cells membrane and the amount of lipid peroxidation products, as well as the concentration of marker enzymes of liver damage (ALT and AST) in blood serum. The experiment was done on Wistar rats which once received intragastrically 6,0 g methanol/kg b.w. as a 50% solution. The animals were decapitated 6, 12 and 24 h and 2, 5 and 7 days after the methanol administration. The liver was evaluated under transmission electron microscope and lipid peroxidation products were determined in the liver homogenate. The serum ALT and AST activity were also assayed. The biochemical results indicate the increase in lipid peroxidation products. The consequence of this is probably the membrane liver cell damage visible in the electron microscope.

Cyclophosphamide-induced generation of reactive oxygen species. Comparison with morphological changes in type II alveolar epithelial cells and lung capillaries

Cyclophosphamide (CP) causes lung toxicity in animals and humans. The mechanisms of pulmonary damage caused by CP are not fully understood. Possibilities include direct toxicity to pulmonary tissue or indirect toxicity through activation of pulmonary inflammatory cells. The aim of the present study was the ultrastructural analysis (in transmission electron microscope) of the changes following CP administration within the structures forming the interalveolar septum of the lungs, particularly type II epithelial cells. An attempt was also made to reveal a correlation between the morphological changes, intensity of lipid peroxidation in lung tissue homogenates and blood serum collected from the left ventricle of the heart and the alterations in the activities of superoxide dismutase (Cu, Zn-SOD) and glutathione reductase (GSSG-R). The experiment used 40 male Wistar rats of 160-180 g body weight (b.w.). The animals were divided into two groups. Group I - (20 animals) were given single intraperitoneal (i.p.) dose of 150 mg CP/1 kg b.w./1 ml PBS. Group II - (20 animals) were given single i.p. dose of 1 ml PBS. All experimental animals were sacrificed after 1 (subgroups I, II-1) and 7 (subgroups I, II-7) days of CP (or PBS) treatment. I.p. administration of CP caused an increase in lipid peroxidation products (MDA-malondialdehyde) in lung tissue homogenates especially in subgroup I-1 (p = 0.00174). No statistical differences, however, were noted in the blood serum MDA levels, although a statistically significant decrease was found in GSSG-R (p = 0.00174) and SOD (p = 0.00174) activities in the serum. The paper discusses a potential link between the findings of biochemical analysis and the morphological changes found within lung tissue. Pulmonary trombopoesis was indicated as a possible mechanism preventing a decrease in blood platelet count following CP administration.

Lipid peroxidation and antioxidant status in the liver, erythrocytes, and serum of rats after methanol intoxication

Lipid peroxidation products measured as a malondialdehyde and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), and concentrations of ascorbic acid, alpha-tocopherol, and glutathione (GSH) were measured in the liver, erythrocytes, and serum of rats 6, 14, and 24 h and 2, 5, and 7 d after treatment with 3 g methanol/kg. GSH-Px and GSSG-R activities, GSH level, and ascorbate concentration in the liver, erythrocytes, and blood serum were significantly decreased. In addition, SOD and alpha-tocopherol in erythrocytes were diminished, while malondialdehyde (MDA) in liver, erythrocytes, and serum were elevated. Further, erythrocyte counts, hemoglobin levels, hematocrit, and mean corpuscular volume (MCV) were reduced. These results indicate that methanol intoxication in rats leads to an increase in the lipid peroxidation and impairment in the antioxidant mechanisms in liver, erythrocytes, and blood serum.

[The effect of protein oxidation modification on protease-antiprotease balance and intracellular proteolysis]

This review describe the oxidative modification of proteins and its effect on the proteases and antiproteases activity. The changes in the proteolytic-antiproteolytic balance and the susceptibility of the protein substrates on proteolysis are also presented.

Glutathione consumption and inactivation of glutathione-related enzymes in liver, erythrocytes and serum of rats after methanol intoxication

The primary metabolic fate of methanol is oxidation to formaldehyde and then to formate. These processes are accompanied by formation of superoxide anion and further hydrogen peroxide. Glutathione plays a unique role in the cellular defense system against xenobiotics. The glutathione (GSH) content and glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-R) activities were measured in liver, erythrocytes and serum of rats. Rats were intoxicated with 3.0 and 6.0 g methanol/kg body wt. and measurements taken after 6, 12 and 24 h and 2, 5 and 7 days of intoxication. The decrease in GSH content and in GSH-related enzyme activity was observed during the whole time-course of the intoxication. The most significant changes were observed in the erythrocytes. The results obtained show that the protection against oxidative damage due to methanol intoxication in rats seems to be less efficient than in control rats.

Activity of liver proteases in experimental methanol intoxication

Intoxication of rats with methanol (1.5 and 3.0 g/kg body weight) led to a significant, time- and dose-dependent decrease in the activities of cathepsins A, B and C, while the activity of cathepsin D was unaffected. The decrease was associated with a different partial release of individual cathepsins to the post-lysosomal fraction.