The protective effect of montelukast sodium on carbon tetrachloride induced hepatopathy in rat

AIM

This study investigates the effects of montelukast sodium (MK) (CysLTLT1 receptor antagonist) on CCl(4)induced hepatopathy on rat.

MATERIAL AND METHODS

We worked on 4 groups of 10 Wistar male rats each. The groups received as follows: group I (control group) - saline, group II - MK 5mg/kg/day i.p. for 5 days, group III - MK 5mg/kg/day i.p., 1 day prior to and 4 days concomitantly with CCl(4) p.o., 0.3ml/Kg/day and group IV - CCl(4), p.o., 0.3ml/Kg/day for 4 days. One day after the last administration, samples of blood were taken and alanine aminotransferase (ALT), total bilirubin (TB), direct bilirubin (DB), malondialdehyde (MDA), catalase (CAT) as well as total antioxidant capacity (TAC) were determined. The histopathological exam was performed. We also determined superoxide dismutase (SOD), MDA, CAT and GSH in liver homogenate.

RESULTS

Compared to group IV, group III exhibited statistically significant lower levels of ALT (318+/-15.75 versus 203.14+/-10.28 UI, p<0.0001), TB (3.16+/-0.30 versus 1.99+/-0.08mg/dl, p<0.0001), MDA in blood and in liver homogenate (4.98+/-1.71 versus 2.15+/-1.18nmol/ml, p=0.0004) and higher levels of SOD and CAT. Histopathologically, group IV presented important macro- and micro-vesicular hepatic steatosis and group III preserved lobular histoarchitecture and had less severe cellular lesions.

CONCLUSION

MK exhibits a partial hepatoprotective effect on rats treated with CCl(4).

[The blood enzymatic antioxidative potential in bronchial asthma patients]

This study aims at assessing the ability of asthma patients to defend themselves against the noxious effects of oxidative stress, known being the inflammatory nature of this disorder. As the anti-radical defence ability of the body is reflected by the antioxidative potential of blood and tissues, our study was based on the determination of the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and CAT/SOD and GPx/SOD ratios in the blood. Except for SOD, the activity of which was lower in asthma patients by -34.08%, CAT and GPx had values increased by +32.18%, respectively, with a resulting increase of CAT/SOD and GPx/SOD ratios. Our data, demonstrating a change in per-oxidants/antioxidants balance in favour of the first ones, seem to suggest that in the treatment of bronchial asthma the association of some compounds with antioxidants effects would be beneficial.

[Glutathione peroxidase, an oxidative stress biomarker, in the menstrual cycle]

The oxygen, through his toxic effects, has determined the human organism to perfectionate multiple and efficient protection systems, especially the GSH-Px.

OBJECTIVES

To study the activity of GSHPx activity in the 0, 14 and 28 days of the menstrual cycle in a group of women with psychiatric disorders.

METHODS

The activity of GSH-Px was investigated in 24 women inpatients from the Psychiatric Department of Murgeni Hospital Vaslui. The GSH-Px level was determined in human serum using Fukuzawa method, modified in the Biochemistry Lab of the "Al. I. Cuza" University, Iaşi.

RESULTS

It has been no correlation between the type of psychiatric disorders and the level of GSHPx. This activity of GSHpx is in direct relationship with the concentration of sexual hormones, showing an hormone dependent enzymatic induction. A growth of the GSHPx activity from the day 0 to the 28th day of the menstrual cycle followed by a sudden decrease at menstruation time have been observed in all age groups. This fact demonstrated the existence of an enzymatic cycle.

[The importance of the use of selenium in the role of an antioxidant in preventing cardiovascular diseases]

The evaluation of the results of the oxygen free radicals (RLO2) formation is a current subject in biology and medicine. The oxidative stress, which is the altering of the balance between the higher activity of oxygen and the enzymatic or nonenzymatic protection systems, may be one of the causes that starts and aggravates a disease. In this context, the supplementation of the diet with selenium, superoxide dismutase, vitamins A, C, E, is considered a primary prevention measure (for the apparently healthy persons) and a secondary one (for those with advancing forms of disease) that is both efficient and modern by utilization of some "drug-food" products. The transversal study realized on a group of 39 blood donors presence of the cardiovascular risk determined by the raising of the prevalence of some atherogenic factors (active smoking, hypercholesterolemia) which is also expressed by the lowering of the level of some oxidative stress indicators (glutathione peroxidase--GSH-Px < 0.139 moli/ml and catalase < 2.20 U/ml). The simultaneous low intake of selenium from the central drinking water supplies in the city of Iaşi (0.1-1 g/l) has permitted us to consider necessary the diet supplementation both with foods rich in vitamins with an antioxidant role and with specific medication with selenium, as a protective micro-element.

[The role of lipid peroxidation and of the antioxidant systems in normal pregnancy and in pre-eclampsia]

Several recent studies have reported that there is an imbalance between increased oxidant status and decreased antioxidant system in women with preeclampsia; this factor may contribute to endothelial lesion, one of the characteristics of the disease. Our studies has examined serum levels of lipid peroxides and of some of the antioxidants (glutathione and glutathione-peroxidase) in women with preeclampsia compared with normal pregnant women. The study was realised on two groups: Group A consisting of 34 normal pregnant women and group B consisting in 20 women with PEC. Serum levels of lipid peroxides have been found markedly increased and of antioxidants markedly decreased in preeclamptic serum compared with normal gestational serum. Lipid peroxides are toxic compounds that damage endothelial cells, increase peripheral vasoconstriction and increase thromboxane synthesis. Our study has pointed out that in PEC there is a deficiency in the antioxidant system which allow, together with the ischemic placenta and activated neutrophils, the enhancement of lipid peroxides. This deficiency in AO system contribute to the development and aggravation of the clinical manifestation in PEC.

[The clinico-epidemiological premises for antioxidant prevention and treatment in chronic myocardial infarct]

The improvement of therapeutic and recoverable proceeding to chronic myocardial infarction (IMC) imposes a complex epidemiological estimation of the global cardiovascular risk, of their clinical and biological status. The retrospective evaluation of the risk factors (RF) by epidemiological methods, in 38 hospitalized prevalence of both constitutional and behavioral factors, and the quantification of the risk state, according to graph Euro 194, has pointed on the fact that 50% of IMC cases have presented a global risk of 10-20%. That justified the application of a preventive conduct in order to continually neutralize the associates FR. The biochemical determinations have allowed to frame the dyslipidemic patients, according to the ARCOL classification in the classes D (29.2%), E (25.0%) and B (20.8%) with direct implication in the adopted therapy. The colorimetric dozing with thyo-barbituric acid of the malonly dialdehyde (MAD) each is a product of the lipidic peroxidation, as well as the interpreting or correlation of the registered values with an evolutive clinic stage, and with the existence of some existing diseases (diabetes, chronic hepatitis etc.) along with signification of other dismethabolical parameters (cholesterol, triglycerides, LDLc, apoB) have confirmed the necessity of a complex therapy, including an antioxidative treatment, having the role to directly inhibit or exclude the free radicals resulted after the oxidative stress of the infarct.

[Glutathione, a biochemical indicator for different types of cellular stress. The change in the GSH level in the brain of rats with hypoxia]

By the ligation of left vertebral artery in some white, adult WISTAR rats, of 150-200 g, anaesthetized with ether, a cerebral hypoxia of 10 minutes was induced. After beheading, there was determined the level of SH-neproteic groups and glutathione (GSH) in the whole heparinized blood and there was observed an important decrease with -15.88% and -16.80% respectively, in comparison with the normal lot (100%), kept under the some laboratory conditions. The GSH level in the neural cytosol is also significantly decreased with -8.66% in rats with hypoxia. The GSH depletion in the induced hypoxia, by our experiment, might be due to the reaction between nitric oxide (NO.) radical and intracellular GSH (blood and neuronal cytosol), considering the literature in this field, and S-nitrosoglutathion (S-NO-GSH) bioactive intermediary is formed and it protects the hypoxied brain against the NO.-dependent cytotoxicity, in the initial phase of hypoxia. The decrease of GSH and SH-neproteic groups level is considered a biochemical marker of the growth of the free radicals level to O2 (NO., O2., OH., H2O2, 1O2), that appear in the hypoxic and/or ischemic stress, but also a major sign in the rol of "scavenger" and antioxidant of the radicals at the cerebral and sanguine level, in the above mentioned conditions.

Antioxidant action of a new flavonic derivative in acute carbon tetrachloride intoxication

The antioxidant potential of a new flavonic derivative named conventionally theophylline-rutoside [TR-1722] was estimated by the measurement of G-6-Pase activity (marker enzyme for the endoplasmic reticulum), catalase activity (enzyme involved in the antioxidant defence process), and total -SH groups from the hepatic homogenate, using CCl4 as a free radical generating model. To show changes in the permeability of the hepatocyte membrane, the activity of lactate dehydrogenase (LDH) in plasma was determined. The obtained results suggest that TR-1722 acts by curtailing both lipid peroxidation and alkylation processes.

[Multidisciplinary epidemiological observations on the role of mineral elements and other environmental factors in inducing essential arterial hypertension]

The results of a pluridisciplinary epidemiological study carried out on a series of 225 adults from rural areas, in whom the prevalence of arterial hypertension disease (AHTD) and borderline (AHTB) was of 19.0% and 14.4%, respectively, are presented. In 19.0% of the carriers of over five associated risk factors for cardiovascular disease, the classical lipid constants (triglycerides-TG. total lipids-TL. total cholesterol-TC. HDL-cholesterol-HDL-c), plasma (PML) and erythrocyte magnesium level (EML), as compared to the degree of drinking water mineralization were determined. The environmental conditions, also expressed in water hardness (21.650 G) or magnesium water intake (85.13 mg/l) correlate in 41.0% of the subjects with a decrease in PML (1.8 mg/l) and in 70.48 with a decrease in EML (4.8 mg/l) through the association of some behavioral or metabolic risk factors: stress, consumption of atherogenic foods, excess alcohol and lipid dysmetabolism (TG: 130-140 mg/l = 59.5%; TL: 8 g%-30.9%; TC: 220 mg/l = 19%; HDL-c: 35 mg/l + 1.9%).

[The role of oxidative stress in the etiology of pre-eclampsia: changes at the GSH and GSH-Px levels in normal pregnancy and pre-eclampsia]

Several recent studies have reported that there is an imbalance of increased oxidant status and decreased antioxidant system in women with preeclampsia and that factor might contribute to the pathogenesis of the disease. The following study examined blood levels of some of the antioxidants (glutathione, glutathione-peroxidase and -SH groups) as markers of lipid peroxidation in women with preeclampsia compared with normal gestation. Blood levels of these antioxidants were found significantly decreased in women with preeclampsia, which allowed us to speculate that there were abnormally increased levels of lipid peroxides. We believe that lipid peroxides are toxic compounds that damage endothelial cells, increase peripheral vasoconstriction and increase thromboxane synthesis and decrease prostacyclin synthesis. We consider that lipid peroxides are not the cause but the effect of oxidative stress induced by ischaemic placenta and leukocytes activation, so the contribute but not induce pathogenesis in preeclampsia.

[The evaluation of a method for determining apolipoproteins as a sensitive indicator in assessing lipid metabolic disorder in a population at risk for essential arterial hypertension (EAHT)]

The increased efficiency of epidemiological screening tests in determining the prevalence of risk factors carriers required the use of highly sensitive markers able at detecting early, in reversible stages, the disturbances in the lipid metabolism genetically induced or acquired during lifetime, known as major risk factors for essential hypertension and other cardiovascular diseases. The authors report the preliminary results of some investigations on the predictive value of apolipoproteins. Immunokits manufactured by BioMérieux--France were used. In 50 admitted patients with essential hypertension and family history of risk, high levels of apoA1 and apoB were recorded although cholesterol and other biological markers were within the normal. At the same time, in our case the apoB/apoA ratio was supraunitary, fact proving the validity of the method.

[Glutathione, a biochemical indicator for different types of cellular oxidative stress. II. Ethanol poisoning]

Eight male volunteers, all alcohol addicts selected from the patients of the Pădureni unit, deprived for a minimum of two weeks of alcohol, but with an at least 2-year history of alcohol addiction, received 0.5 ml absolute alcohol/kg body weight. Following dynamically the alteration of plasma reduced glutathione content, a significant increase (+8.27%) 30 minutes after alcohol ingestion and a decrease (-7.02%) before ingestion, as compared to plasma glutathione level in sex and age-matched clinically normal subject (100%) was noticed. The change in the --SH groups content in plasma after chronic alcohol ingestion leads to the occurrence of cell oxidative stress, as well as to a decreased resistance of hepatic cell and whole body as a result of the lipid peroxidation process and/or occurrence of detrimental reactive radical species, issuing from O2.

[The effect of the ascorbic acid-Cu (II) couple on enzyme activity]

Ascorbic acid (AA), Cu (II) and their association affect in different ways the activity of G6P-ase and G6PDH from the rat hepatic cytoplasm enriched in microsomes. G6P-ase is inhibited at a wide range of concentrations: 200-2 mM AA and 1-0.1 mM Cu (II). The association AA-Cu in the above mentioned concentrations, proved to be a stronger inhibitor than AA or Cu (II) introduced separately in the incubation medium. The activity of G6PDH is stimulated by AA-Cu (II) association and inhibited by AA in the dialyzed and nondialyzed cytoplasm. Cu (II) inhibits the activity of G6PDH in the nondialyzed cytoplasm and stimulates it following dialysis. The compounds with recognized antiradical action prove to be inefficient in restoring the activity of G6PDH affected by the AA-Cu (II) association.

Efficacy of multidisciplinary epidemiological screening in the primary prevention of essential arterial hypertension

An epidemiological screening of 8011 industrial workers and 7090 pupils made possible the active detection of some risk factors carriers and of those individuals with borderline essential arterial hypertension (BEAHT) and essential arterial hypertension disease (EAHTD). It was noticed that the association of 2-4 risk factors is more common in the subjects with BEAHT or EAHTD, fact indicating their increased aggressivity in the various types of associations present in the same carrier. In the worker series a prevalence of 16.2%-18.0% for BEAHT and 6.3%-7.1% for EAHTD as compared to 4.3%-6.0% and 4.9%-5.3%, respectively, in the pupil series were recorded. The epidemiological screening had a strong educational effect, reflected in an increased cooperation of the screened population, and revealed the fact that the risk factor carrier state and the increased arterial pressure levels were ignored, at long term, by 50-90% of the investigated subjects.

[Glutathione and the redox index in different types of cellular oxidative stress. I. Acrylonitrile (ACN) poisoning]

The professional poisoning with acrylonitrile of some subjects induced a significant decrease of reduced glutathione (81.30%), redox ratio reduced glutathione/oxidized glutathione (90.74%) and "Benzi-redox index" (55.84%) but an increase of oxidized glutathione level (112.6%) as compared to normal controls (100%). This proves the occurrence, in time, of the cellular oxidative stress and/or were obtained.

[Sensivity of some enzymes in Guérin tumours after the administration of Nystatin MC]

In the animals with a 24 hours and 15 days transplant of Guérin lymphotropic epithelioma Nystatin MC in a dose of 800 mg/K body weight/day and 1 800 mg/K body weight/day every 3 and 6 hours daily for 8 days was injected subcutaneously. The dosing of the activity of gluthamin-synthetase, MDH and catalase in tumours of 8, 23, and 38 days showed that Nystatin MC disturbed the activity of the enzymes from mythocondries and cytoplasm especially in the 8 and 23 days tumours, influencing the glycolitic process. The gluthamin-synthesis was inhibited during the entire tumoral activity period, reaching after treatment almost normal values. Cytoplasmic MDH was influenced by the treatment in relation with the age of the tumour and the used dose. I