Purple grape juice consumption during the gestation reduces acetylcholinesterase activity and oxidative stress levels provoked by high-fat diet in hippocampus from adult female rats descendants.

The enzyme acetylcholinesterase participates in the end of cholinergic transmission and it has been shown that its activity is increased in some diseases that affect the brain, including Alzheimer disease. The objective of this study was to investigate the effect of purple grape juice consumption with or without high-fat diet in the gestational and lactation period on acetylcholinesterase activity and oxidative stress parameters in the hippocampus of female descendants. During pregnancy and lactation, 40 female Wistar rats received a control diet or a high-fat diet, with half of them receiving grape juice. After lactation, the female descendants received water and control diet in ad libitum until euthanasia on the 120 postnatal day. Hippocampus from were removed for analysis of AChE activity, protein oxidation and lipid peroxidation. It was observed that high-fat diet consumption during the pregnancy increased the AChE activity and the grape juice reduced this activity in descendants. The same was observed in protein oxidation, the descendants from high-fat diet had significantly highest values, and grape juice decreased the levels. We conclude that dietary choices during pregnancy can alter the acetylcholinesterase levels and grape juice is an important alternative to improve this function in adulthood.

Subchronic treatment with acai frozen pulp prevents the brain oxidative damage in rats with acute liver failure.

Acai has been used by the population due to its high nutritional value and its benefits to health, such as its antioxidant properties. The aim of this study was to evaluate the protective effect of acai frozen pulp on oxidative stress parameters in cerebral cortex, hippocampus and cerebellum of Wistar rats treated with carbon tetrachloride (CCl4). Thirty male Wistar rats (90-day-old) were orally treated with water or acai frozen pulp for 14 days (7 µL/g). On the 15th day, half of the animals received treatment with mineral oil and the other half with CCl4 (3.0 mL/kg). The cerebral cortex, hippocampus and cerebellum were dissected and used for analysis of creatine kinase activity (CK), thiobarbituric acid reactive substances (TBARS), carbonyl, sulfhydryl, and the activity of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). Statistical analysis was performed by ANOVA followed by Tukey's post-test. CCl4 was able to inhibit CK activity in all tissues tested and to provoke lipid damage in cerebral cortex and cerebellum, and protein damage in the three tissues tested. CCl4 enhanced CAT activity in the cerebral cortex, and inhibited CAT activity in the hippocampus and cerebellum and reduced SOD activity in all tissues studied. Acai frozen pulp prevented the inhibition of CK, TBARS, carbonyl and CAT activity in all brain structures and only in hippocampus for SOD activity. Therefore, acai frozen pulp has antioxidant properties and maybe could be useful in the treatment of some diseases that affect the central nervous system that are associated with oxidative damage.

Evaluation of antioxidant activity of grapevine leaves extracts (Vitis labrusca) in liver of Wistar rats.

The aim of this study was to evaluate the hepatoprotection of organic and conventional grapevine leaves extract (Vitis labrusca). The total polyphenol content and the isolate polyphenols by HPLC were evaluate. The animals received intraperitoneal injections of saline or extracts (conventional or organic - 30 mg/kg) for 14 days. On day 15, the rats received carbon tetrachloride (CCl4) or mineral oil (i.p.). After 4h, the animals were euthanized. The analysis of the liver enzymes activity (AST, ALT, GGT) was performed using serum, obtained by blood and the levels of lipid peroxidation (TBARS), protein oxidation (carbonyl), and the activity of antioxidant enzymes superoxide dismutase and catalase were analyzed in the liver. The results showed that the organic extract is richer in polyphenol and resveratrol than the conventional one. Both extracts prevent lipid peroxidation and protein oxidation generated by CCl4. Moreover, the extracts demonstrated ability to modulate the activity of SOD and CAT, as well as to establish a balance in the ratio of SOD/CAT. We also found that the CCl4 increased the levels of AST and GGT, and that both extracts prevent this. These results indicate that grapevine leaves extracts, both, organic and conventional, can prevent liver disorders.

Method validation for determination of metals in Vitis labrusca L. grapevine leaf extracts by inductively coupled plasma mass spectrometry (ICP-MS).

Vitis labrusca L. is the main species used for wine and juice production in Brazil. The grapevine leaves can be used both as functional foods and as cheapest sources for the extraction of phenolic compounds. Besides the antioxidant activity, grapevine leaves exhibited significant anti-inflammatory activity. Therefore, the aim of this study was to develop and validate an analytical methodology to determine the metals selenium (96Se), chromium (53Cr), nickel (62Ni), cadmium (111Cd) and lead (206Pb) in 30 samples of grapevine leaf extracts (Vitis labrusca, Bordo cultivar) using inductively coupled plasma mass spectrometry (ICP-MS). To obtain the grapevine leaf extracts the samples were milled, weighed and digested in microwave oven with nitric acid. The method showed linearity, precision, accuracy and limits of quantification and detection acceptable for INMETRO protocol validation of analytical methods. Therefore, the method using ICP-MS was developed and validated to determine metals concentrations in grapevine leaves of Vitis labrusca L. and the proposed method could be applied in routine analytical laboratory.

Carbon Tetrachloride Increases the Pro-inflammatory Cytokines Levels in Different Brain Areas of Wistar Rats: The Protective Effect of Acai Frozen Pulp.

Acai offers health benefits associated with its high antioxidante capacity, phytochemical composition, nutritional and sensory value. Therefore, the objective of this study was to evaluate the protective effect of acai frozen pulp on carbon tetrachloride (CCl4)-induced damage via modulation of anti- and pro-inflammatory cytokines in rat brain tissue. The rats were treated via oral (gavage) daily with water or acai frozen pulp for 14 days at a dose of 7 µL/g. On the 15th day, the animals in each group received a single intraperitoneal injection of CCl4 in a dose of 3.0 mL/kg or the same volume of mineral oil. After 4 h, the animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were dissected and homogenated to evaluate the levels of tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß), interleukin 18 (IL-18), interleukin 6 (IL-6) and interleukin 10 (IL-10). Data were statistically analyzed by analysis of variance followed by the Tukey post hoc test. It was observed that CCl4 increased TNF-α, IL-1ß and IL-18 levels in all brain tissues, and that acai frozen pulp was able to prevent this increase. IL-6 and IL-10 brain tissue levels remained unchanged during all treatments. CCl4 experimental model was suitable to investigate brain tissue anti and pro-inflammatory cytokines. Acai frozen pulp prevented an increase in IL-1ß, IL-18 and TNF-α, while IL-6 and IL-10 levels remained unchanged. The precise pathway by which inflammation contribute to hepatic encephalopathy, as well as to how this pathway can be modulated, is still under investigation.

Acute exposure to the vinyl chalcogenide 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one induces oxidative stress in different brain area of rats.

The mechanisms that lead to the onset of organoselenium intoxication are still poorly understood. Therefore, in the present study, we investigated the effect of acute administration of 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one on some parameters of oxidative stress and on the activity of creatine kinase (CK) in different brain areas and on the behaviour in the open field test of 90-day-old male rats. Animals (n = 10/group) were treated intraperitoneally with a single dose of the organoselenium (125, 250 or 500 µg kg(-1) ), and after 1 h of the drug administration, they were exposed to the open field test, and behaviour parameters were recorded. Immediately after they were euthanized, cerebral cortex, hippocampus and cerebellum were dissected for measurement of thiobarbituric acid reactive substances (TBARS), carbonyl, sulfhydryl, catalase (CAT), superoxide dismutase (SOD) and CK activity. Our results showed that the dose of 500 µg kg(-1) of the organoselenium increased the locomotion and rearing behaviours in the open field test. Moreover, the organochalcogen enhanced TBARS in the cerebral cortex and cerebellum and increased the oxidation of proteins (carbonyl) only in the cerebral cortex. Sulfhydryl content was reduced in all brain areas, CAT activity enhanced in the hippocampus and reduced in the cerebellum and SOD activity increased in all brain structures. The organoselenium also inhibited CK activity in the cerebral cortex. Therefore, changes in motor behaviour, redox state and energy homeostasis in rats treated acutely with organoselenium support the hypotheses that the brain is a potential target for the organochalcogen action. Ltd.

In vitro antioxidant capacity of tea of Echinodorus grandiforus, "leather hat," in Wistar rat liver.

Oxidative stress has been considered as one of the factors responsible for hepatic diseases, which sometimes require new ways of treatment. The present study aimed to evaluate the in vitro antioxidant capacity of the tea of Echinodorus grandiforus ("leather hat" plant) in rat liver. Different preparations of tea were evaluated for phenolic composition, antioxidant activity by DPPH assay and ability to inhibit lipid peroxidation induced by copper sulfate. The antioxidant activity was assessed in liver tissue treated with sodium azide in the presence or absence of tea by assays for lipid peroxidation (TBARS), protein oxidation (carbonyl) and the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). The results show that different preparations of tea are important sources of polyphenols and contain theobromine, catechin and vitexin. Furthermore, the results indicate that this tea exhibits an antioxidant activity by its ability to scavenge DPPH radical. Different preparations of tea prevented damage to lipids and proteins induced by sodium azide, as well as assisting in restoring CAT and SOD activities. Thus, it can be seen that E. grandiforus tea had antioxidant activity in serum and liver being able to prevent oxidative damages generated by sodium azide.

Effect of chronic treatment with conventional and organic purple grape juices (Vitis labrusca) on rats fed with high-fat diet.

Serra Gaucha is described as the most important wine region of Brazil. Regarding cultivars widespread in the Serra Gaucha, about 90 % of the area is occupied by vines of Vitis labrusca that is the most important specie used in grape juice production. The objective of this study was to investigate the antioxidant and neuroprotective effect of chronic intake of purple grape juice (organic and conventional) from Bordo variety (V. labrusca) on oxidative stress in different brain regions of rats supplemented with high-fat diet (HFD) for 3 months. A total of 40 male rats were randomly divided into 4 groups. Group 1 received a standard diet and water, group 2 HFD and water, group 3 HFD and conventional grape juice (CGJ), and group 4 HFD and organic grape juice (OGJ). All groups had free access to food and drink and after 3 months of treatment the rats were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum isolated and homogenized on ice for oxidative stress analysis. We observed that the consumption of calories in HFD and control groups, were higher than the groups supplemented with HFD and grape juices and that HFD diet group gain more weight than the other animals. Our results also demonstrated that HDF enhanced lipid peroxidation (TBARS) and protein damage (carbonyl) in cerebral cortex and hippocampus, reduced the non-enzymatic antioxidants defenses (sulfhydryl) in cerebral cortex and cerebellum, reduced catalase and superoxide dismutase activities in all brain tissues and enhanced nitric oxide production in all cerebral tissues. CGJ and OGJ were able to ameliorate these oxidative alterations, being OGJ more effective in this protection. Therefore, grape juices could be useful in the treatment of some neurodegenerative diseases associated with oxidative damage.

Effects of ß-alanine administration on selected parameters of oxidative stress and phosphoryltransfer network in cerebral cortex and cerebellum of rats.

ß-Alanine is a ß-amino acid derivative of the degradation of pyrimidine uracil and precursor of the oxidative substrate acetyl-coenzyme A (acetyl-CoA). The accumulation of ß-alanine occurs in ß-alaninemia, an inborn error of metabolism. Patients with ß-alaninemia may develop neurological abnormalities whose mechanisms are far from being understood. In this study we evaluated the effects of ß-alanine administration on some parameters of oxidative stress and on creatine kinase, pyruvate kinase, and adenylate kinase in cerebral cortex and cerebellum of 21-day-old rats. The animals received three peritoneal injections of ß-alanine (0.3 mg /g of body weight) and the controls received the same volume (10 µL/g of body weight) of saline solution (NaCl 0.85 %) at 3 h intervals. CSF levels of ß-alanine increased five times, achieving 80 µM in the rats receiving the amino acid. The results of ß-alanine administration in the parameters of oxidative stress were similar in both tissues studied: reduction of superoxide dismutase activity, increased oxidation of 2',7'-dihydrodichlorofluorescein, total content of sulfhydryl and catalase activity. However, the results of the phosphoryltransfer network enzymes were similar in all enzymes, but different in the tissues studied: the ß-alanine administration was able to inhibit the enzyme pyruvate kinase, cytosolic creatine kinase, and adenylate kinase activities in cerebral cortex, and increase in cerebellum. In case this also occurs in the patients, these results suggest that oxidative stress and alteration of the phosphoryltransfer network may be involved in the pathophysiology of ß-alaninemia. Moreover, the ingestion of ß-alanine to improve muscular performance deserves more attention in respect to possible side-effects.

Effect of chronic administration of the vinyl chalcogenide 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one on oxidative stress in different brain areas of rats.

Selenium (Se) is an essential mineral for mammals. It is a nutrient related to the complex metabolic and enzymatic functions. Although Se has important physiological functions in the cells, organic compounds of Se can be extremely toxic, and may affect the central nervous system. This study aims to investigate the effect of the chronic treatment with the vinyl chalcogenide 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one on some parameters of oxidative stress in the brain of rats. Animals received the vinyl chalcogenide (125, 250 or 500 µg/kg body weight) intraperitoneally once a day during 30 days. The cerebral cortex, the hippocampus, and the cerebellum were dissected and homogenized in KCl. Afterward, thiobarbituric acid reactive substances (TBARS), carbonyl, sulfhydryl, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured in the brain. Results showed that the organoselenium enhanced TBARS in the cerebral cortex of rats but the compound was not able to change carbonyl levels. Furthermore, the organoselenium reduced thiol groups measured by the sulfhydryl assay in all tissues studied. The activity of the antioxidant enzyme CAT was increased by the organochalcogen in the cerebral cortex and in the cerebellum, and the activity of SOD was increased in the hippocampus. On the other hand, the activity of the antioxidant enzyme GPx was reduced in all brain structures. Our findings indicate that this organoselenium compound induces oxidative stress in different brain regions of rats, corroborating to the fact that this tissue is a potential target for organochalcogen action.

Tyrosine impairs enzymes of energy metabolism in cerebral cortex of rats.

Tyrosine levels are abnormally elevated in tissues and physiological fluids of patients with inborn errors of tyrosine catabolism, especially in tyrosinemia type II, which is caused by deficiency of tyrosine aminotransferase and provokes eyes, skin, and central nervous system disturbances. Considering that the mechanisms of brain damage in these disorders are poorly known, in this study, we investigated the in vivo and in vitro effects of tyrosine on some parameters of energy metabolism in cerebral cortex of 14-day-old Wistar rats. We observed that 2 mM tyrosine inhibited in vitro the pyruvate kinase (PK) activity and that this inhibition was prevented by 1 mM reduced glutathione with 30, 60, and 90 min of preincubation. Moreover, administration of tyrosine methyl ester (TME) (0.5 mg/g of body weight) decreased the activity of PK and this reduction was prevented by pre-treatment with creatine (Cr). On the other hand, tyrosine did not alter adenylate kinase (AK) activity in vitro, but administration of TME enhanced AK activity not prevented by Cr pre-treatment. Finally, TME administration decreased the activity of CK from cytosolic and mitochondrial fractions and this diminution was prevented by Cr pre-treatment. The results suggest that tyrosine alters essential sulfhydryl groups necessary for CK and PK functions, possibly through oxidative stress. In case this also occurs in the patients, it is possible that energy metabolism alterations may contribute, along with other mechanisms, to the neurological dysfunction of hypertyrosinemias.

Acute administration of the organochalcogen 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one induces biochemical and hematological disorders in male rats.

Organochalcogens are extensively produced and employed by industry and agriculture, and the risk of occupational and environmental toxicity to them has been poorly understood. Here, we investigated the acute effect of a new organochalcogen 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one on biochemical and hematological parameters in male Wistar rats. The animals were treated with a single intraperitoneal injection of the organochalcogen at doses of 125, 250 or 500 µg·kg(-1). After 60 min, the animals were sacrificed by decapitation, and the trunk blood was collected for determination of glucose, triglycerides, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase, lactate dehydrogenase, urea, creatinine, C-reactive protein, red blood cells, hematocrit, hemoglobin and white blood cells (WBC). Our results showed a reduction in cholesterol levels in all treated groups, an increase in ALT activity at doses of 250 and 500 µg·kg(-1), a decrease of hemoglobin and an increase in WBC in animals that received 250 and 500 µg·kg(-1) of the organoselenium. In addition, we observed an increase in neutrophil counts at 125 µg·kg(-1) dose and a decrease at 500 µg·kg(-1) dose. We also verified an increase in lymphocyte counts at the dose of 500 µg·kg(-1). Thus, the present study shows that the acute treatment with this new organochalcogen causes biochemical changes and hematological disorders in male rats.

Gestational purple grape juice consumption does not change fetal ductus arteriosus constriction in Wistar rats.

Grape juice consumption may influence the early occurrence of ductal constriction during pregnancy, since the consumption of foods rich in polyphenols can be linked to the premature constriction of the ductus arteriosus. This study aimed to evaluate the effect of purple grape juice consumption during gestation on fetal ductus arteriosus closure, prostaglandin levels, and oxidative stress markers in Wistar rats. We divided 18 pregnant rats into four groups: a control group (C), a single-dose grape juice group (SDGJ), a two-dose grape juice group (TDGJ) of 7 µl/g body weight per day, and an indomethacin group (I). Blood was collected on gestational day (GD) 0, 14, and 20. Prostaglandin levels were measured, and the livers and hearts were removed from the mothers and fetuses for oxidative stress analysis; histology of the fetal ductus arteriosus was performed. Prostaglandin levels (pg/ml) at GD 20 were (C:1462.10 ± 314.61); (SDGJ:987.66 ± 86.25); (TDGJ:1290.00 ± 221.57), and (I:584.75 ± 46.77). Fetal ductus arteriosus closure occurred only in the indomethacin group. Lipid peroxidation evaluated through thiobarbituric acid reactive substances (nmol/mg protein) in maternal livers was lower in the grape juice groups (C: 4.11 ± 0.76 nmol/mg protein), (SDGJ: 2.34 ± 0.36), (TDGJ: 1.52 ± 0.18), and (I: 4.20 ± 0.76). Sulfhydryls (nmol/mg protein) were lower in the TDGJ group (C:763.59 ± 61.38 nmol/mg protein), (SDGJ:978.88 ± 158.81), (TDGJ:385.32 ± 86.78), and (I:727.72 ± 49.12). Also, superoxide dismutase activity (USOD/mg protein) was higher in fetal hearts in this group: (C:5.29 ± 0.33), (SDGJ:4.48 ± 0.47), (TDGJ:7.35 ± 0.43), and (I:6.00 ± 0.18). We conclude that grape juice consumption in pregnancy does not induce ductus arteriosus closure in the fetus and presented potential antioxidant effects.

The organochalcogen 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one induces oxidative stress in heart, liver, and kidney of rats.

The objective of this study was to investigate the in vitro effects of the organochalcogen 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one on some parameters of oxidative stress in liver, kidney, and heart of 10-day-old rats. The homogenates of liver, kidney, and heart were incubated for 1 h in the absence (control) or in the presence of 1, 10, or 30 µM of the organoselenium and thiobarbituric acid reactive substances, carbonyl, and the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were measured. First, we tested the influence of the compound on 1,1-diphenyl-2-picrylhydrazyl (DPPH(•)) radical scavenging and verified that the organochalcogen did not have any antioxidant properties. We observed an increase of lipid peroxidation in all concentrations tested in heart and kidney, while in liver only in the concentrations of 10 and 30 µM. Moreover, we also verified an enhance of protein oxidation in the concentrations of 10 and 30 µM in kidney. On the other hand, the compound caused a reduction on the activity of CAT in heart (10 and 30 µM), liver (30 µM), and kidney (30 µM). The activity of SOD was increased in heart (10 and 30 µM), while in liver (30 µM) and in kidney (10 and 30 µM) the activity was reduced. Our findings indicate that this organoselenium compound induces oxidative stress in liver, heart, and kidney of immature rats, collaborating to the fact that these tissues are potential targets for the organochalcogen action.

Tyrosine inhibits creatine kinase activity in cerebral cortex of young rats.

Tyrosine accumulates in inborn errors of tyrosine catabolism, especially in tyrosinemia type II, where tyrosine levels are highly elevated in tissues and physiological fluids of affected patients. Tyrosinemia type II is a disorder of autosomal recessive inheritance characterized by neurological symptoms similar to those observed in patients with creatine deficiency syndromes. Considering that the mechanisms of brain damage in these disorders are poorly known, in the present study our main objective was to investigate the in vivo and in vitro effects of different concentrations and preincubation times of tyrosine on cytosolic and mitochondrial creatine kinase activities of the cerebral cortex from 14-day-old Wistar rats. The cytosolic CK was reduced by 15% at 1 mM and 32% at 2 mM tyrosine. Similarly, the mitochondrial CK was inhibited by 15% at 1 mM and 22% at 2 mM tyrosine. We observed that the inhibition caused by tyrosine was concentration-dependent and was prevented by reduced glutathione. Results also indicated that mitochondrial, but not cytosolic creatine kinase activity was inhibited by tyrosine in a time-dependent way. Finally, a single injection of L-Tyrosine methyl ester administered i.p. decreased cytosolic (31%) and mitochondrial (18%) creatine kinase activities of brain cortex from rats. Considering that creatine kinase is an enzyme dependent of thiol residues for its function and tyrosine induces oxidative stress, the results suggest that the inhibition caused by tyrosine might occur by oxidation of essential sulfhydryl groups of the enzyme. In case this also occurs in patients with tyrosinemia, it is possible that creatine kinase inhibition may contribute to the neurological dysfunction characteristic of tyrosinemia.

Hepatoprotective, cardioprotective, and renal-protective effects of organic and conventional grapevine leaf extracts on Wistar rat tissues.

The purpose of this study was to evaluate the beneficial effects of organic and conventional grapevine (Vitis labrusca L.) leaf extracts in reducing hydrogen peroxide-induced stress in the liver, heart and kidney of Wistar rats by measuring lipids and proteins damages (carbonyl assay), as well as the activity of the antioxidant enzymes superoxide dismutase and catalase. The preincubation with 5 mg/mL of organic and conventional grapevine (Vitis labrusca L.) leaf extracts prevented both lipids and proteins oxidative damages in all tissues analyzed. The organic leaf extract was able to restore superoxide dismutase (kidney and liver) and catalase (heart) activities, which were modified by the treatment with H(2)O(2). The conventional extract was able to restore only the catalase activity in liver and heart tissues. The beneficial effects of the V labrusca leaf extract shown in this study could probably be important for formulating dietary supplements, as well as for developing new ingredients with improved antioxidant properties from other plant sources.

The effect of consumption of purple grape juice in the gestational period on oxidative stress parameters in Wistar rat foetuses.

This study aimed to evaluate the effects of purple grape juice consumption in pregnancy on oxidative stress parameters in Wistar rat fetuses. Twenty-four pregnant rats were divided into five groups: control group, indomethacin group (received a single dose of indomethacin in DG20), group grape juice DG14 (received an amount for 14 days/first and second gestational trim), group grape juice DG20 (received a dose throughout the gestational period), group grape juice two doses (received two doses, at morning and afternoon). On the 20th day of pregnancy (DG20), rats were anesthetized, and a cesarean section was performed to obtain the fetuses. A sample of liver, heart, and total brain of fetuses was collected for oxidative stress analyses. Values P<0.05 were considered significant. In fetuses' heart, we observed that the grape juice two dose group decreased sulfhydryl and increased SOD. In the liver, the grape juice decreased TBARS and SOD. There was a decrease in carbonyl and sulfhydryl in the indomethacin and grape juice one dose groups in the brain. We conclude that indomethacin altered oxidative stress parameters only in the fetal brain, and grape juice was presented as an important modulator of antioxidant capacity when consumed in a dose.

Effect of acute administration of 3-butyl-1-phenyl-2-(phenyltelluro)oct-en-1-one on oxidative stress in cerebral cortex, hippocampus, and cerebellum of rats.

Organotellurium compounds have been synthesized since 1840, but pharmacological and toxicological studies about them are still incipient. Therefore, the objective of this study was to verify the effect of acute administration of the organochalcogen 3-butyl-1-phenyl-2-(phenyltelluro)oct-en-1-one on some parameters of oxidative stress in the brain of 30-day-old rats. Animals were treated intraperitoneally with a single dose of the organotellurium (125, 250, or 500 µg/kg body weight) and sacrificed 60 min after the injection. The cerebral cortex, the hippocampus, and the cerebellum were dissected and homogenized in KCl. Afterward, thiobarbituric acid reactive substances (TBARS), carbonyl, sulfhydryl, catalase (CAT), superoxide dismutase (SOD), nitric oxide (NO) formation, and hydroxyl radical production were measured in the brain. The organotellurium enhanced TBARS in the cerebral cortex and the hippocampus, and increased protein damage (carbonyl) in the cerebral cortex and the cerebellum. In contrast, the compound provoked a reduced loss of thiol groups measured by the sulfhydryl assay in all the tissues studied. Furthermore, the activity of the antioxidant enzyme CAT was reduced by the organochalcogen in the cerebral cortex and the cerebellum, and the activity of SOD was inhibited in all the brain tissues. Moreover, NO production was increased in the cerebral cortex and the cerebellum by this organochalcogen, and hydroxyl radical formation was also enhanced in the cerebral cortex. Our findings indicate that this organotellurium compound induces oxidative stress in the brain of rats, corroborating that this tissue is a potential target for organochalcogen action.

Inhibition of creatine kinase activity by 3-butyl-1-phenyl-2-(phenyltelluro)oct-en-1-one in the cerebral cortex and cerebellum of young rats.

In the present study, we investigated the potential in vitro toxicity of the tellurium compound 3-butyl-1-phenyl-2-(phenyltelluro)oct-en-1-one on creatine kinase activity in cerebral cortex and cerebellum of 30-day-old Wistar rats. First, enriched mitochondrial and cytosolic fractions from the two tissues were pre-incubated for 30 min in the presence or absence of 1, 5 or 20 microm of organotellurium and the creatine kinase activity was measured. The organochalcogen reduced creatine kinase activity in a concentration-dependent pattern in the two tissues studied. Furthermore, the enzyme activity was performed after pre-incubation for 30, 60 or 90 min in the presence of 5 microm of the organotellurium. The compound inhibited creatine kinase activity in a time-dependent way in the enriched mitochondrial fraction of both tissues, but not in the cytosolic fraction, indicating different mechanisms for the organochalcogen in the mitochondrial and in the cytosolic creatine kinase. Pre-incubation of tellurium compound with reduced glutathione suggests that creatine kinase activity inhibition might be caused by direct interaction with thiol groups or by oxidative stress. Our findings suggest that creatine kinase inhibition may be one of the mechanisms by which this organotellurium could cause toxicity to the rat brain.

Effect of in vitro exposure of human serum to 3-butyl-1-phenyl-2-(phenyltelluro)oct-en-1-one on oxidative stress.

The objective of this study was to verify the effect of the organochalcogen 3-butyl-1-phenyl-2-(phenyltelluro)oct-en-1-one on some parameters of oxidative stress in human serum. Serum of volunteers were incubated for 30 min in the presence or absence of 1, 10, or 30 microM of 3-butyl-1-phenyl-2-(phenyltelluro)oct-en-1-one and oxidative stress was measured. First, we tested the influence of the compound on 1,1-diphenyl-2-picrylhydrazyl (DPPH(*)) radical-scavenging and verified that the organotellurium did not have any antioxidant properties. The organochalcogen was capable to enhance TBARS but the compound was not able to alter carbonyl assay. Furthermore, the organochalcogen provoked a reduction of protein thiol groups measured by the sulfhydryl assay. Moreover, the organotellurium enhanced the activity of catalase and superoxide dismutase, inhibited the activity of glutathione peroxidase and did not modify the glutathione S-transferase activity. Furthermore, nitric oxide production and hydroxyl radical activity were not affected by the compound. Our findings showed that this organochalcogen induces oxidative stress in human serum, indicating that this compound is potentially toxic to human beings.