Effect of Acanthopanax senticosus on the accumulation of cadmium and on the immune response of spleen cells.

Exposure to cadmium (Cd) is known to alter immune responses. Acanthopanax senticosus (Rupr. et Maxim.) Harms (AS) extract, an antioxidant-containing complex of phenolic compounds, tetracyclic triterpenoids/steroids, and polysaccharides, is known to produce Cd mobilization and excretion in vivo. Building upon earlier findings, the aim of the study was to evaluate the effects of an AS extract on Cd accumulation and changes in the presence of splenic immune cells in hosts during a chronic metal exposure. Chronic Cd exposure of BALB/c mice was induced by providing them solutions containing different levels of CdCl2 (25 or 250 mg/L) in double-distilled water, with/without a concurrent presence of AS root extract (approximately 151 g material/L), for 8 wk. At the study end, Cd levels in spleen were measured. Levels of key splenic immune cells, including macrophages, T-lymphocytes, and B-lymphocytes, were determined by immunohistochemistry using, respectively, CD68, CD3, and CD20 antibodies. The results indicated that chronic consumption of AS extract in the presence of the high dose of CdCl2 led to a significant decrease in Cd levels in mouse spleen. The effects of AS on the lower CdCl2 dose were less apparent. In addition, the presence of AS and Cd increased the amount of macrophages and both B and T lymphocytes in mouse spleen relative to concentrations that were lowered as a result of chronic metal only intake.

Antioxidant effects of Camellia sinensis L. extract in patients with type 2 diabetes.

The prevalence of diabetes mellitus (DM) has dramatically increased in the past decade. Furthermore, increasing evidence from research shows that oxidative stress (OS) plays a crucial role in the pathogenesis of diabetes and in its complications. A search for ways to reduce oxidative damage has become the focus of interest for the majority of scientists. In this study, we determined the radical scavenging activity of single green tea constituents by using an on-line high performance liquid chromatography (HPLC)-2,2-diphenyl-1-picrylhydrazyl (DPPH) method and evaluated the antioxidant effects on type 2 diabetic patients by performing a double-blind, placebo-controlled study. Epigallocatechin gallate was identified as the most potent antioxidant, contributing approximately 50% of the total antioxidant capacity of green tea extract. We also found a statistically significant decrement of lipid peroxidation markers in patients treated with green tea extract after 9 months or after 18 months of follow-up. Overall, these findings are attractive for diabetic patients, helping them to keep a high level of performance and well-being, which ultimately may delay the time of disability and reduce mortality.

Selective induction of IL-6 by aluminum-induced oxidative stress can be prevented by selenium.

In this study the acute toxic effects of aluminum (Al) on mice have been investigated, including the interactions of Al and selenium (Se). Focus was put on the systemic effects of (co)exposure to Al and Se as a reflection of the redox status in the liver, kidney and brain. Short-term exposure (16 h) to Al resulted in an increase in the systemic inflammation parameters IL-6 and PAI-1, whereas serum levels of TNF-α remained unaffected. The different response pattern of IL-6 and TNF-α probably indicates an increased intracellular oxidative stress and altered redox status in the liver, because the selective increase in IL-6 serves as a protective intrahepatocellular process driven by oxidative stress. The intracellular glutathione concentration GSHtot decreased significantly upon Al exposure. Both the increase in IL-6 and decrease in glutathione status could be prevented by co-exposure to Se, but not the increase in PAI-1. The redox status of the kidney and brain was not markedly affected. Therefore it was concluded that short-term exposure to Al causes adverse effects on the intracellular oxidative stress processes in the liver, as reflected by the selective increase in the IL-6 concentration. This process can be restored by co-administration of the trace element Se as a part of the glutathione redox system.

Protective effect of selenium on aluminium-induced oxidative stress in mouse liver in vivo.

The aim of the study was to evaluate possible protective effects of selenium (Se) against systemic aluminium (Al) toxicity and the redox status of mouse liver after short-term (16 h) exposure to Al in vivo. BALB/c mice were injected i.p. with AlCl(3) (25mg Al(3+) per kg of body mass) or/and Na(2)SeO(3) (1.25mg Se per kg of body mass). The 4-fold increased activity of ALT in serum showed systemic hepatotoxicity that Se could not prevent by competitive mechanisms. The protective effects of Se could only be observed on intracellular oxidative stress events as determined by glutathione status. Exposure to Al leads to the decrease in the total glutathione (GSH(tot)) and GSH/GSSG redox ratio to about 50% of the control. Upon co-exposure to Se+Al, the concentration of GSH(tot) and the redox ratio was restored to the control values. Our results indicate that Se did not have a protective effect on Al-linked liver toxicity, but did ameliorate intracellular oxidative stress processes mediated by glutathione.

Effect of anoxia and Polyscias filicifolia Bailey biomass tincture on the activity of tRNA and aminoacyl-tRNA synthetases in isolated pig heart.

OBJECTIVE: The aim of this study was to investigate effect of anoxia and Polyscias filicifolia Bailey biomass tincture on the activities of different tRNA and aminoacyl-tRNA synthetases in isolated pig heart. MATERIAL AND METHODS: The isolated pig heart was perfused according to the modified method of Langendorf, using an artificial blood circulation apparatus. Anoxia 20 min in duration was performed by perfusion of isolated heart with Krebs-Henseleit bicarbonate buffer saturated with gas mixture (95% N(2) and 5% CO(2)). Control heart was perfused with the same buffer saturated with gas mixture (95% O(2) and 5% CO(2)). Effect of Polyscias filicifolia Bailey biomass tincture was evaluated by perfusion of isolated heart with a buffer containing tincture. Total tRNA and aminoacyl-tRNA synthetases were isolated from pig heart. Activities of tRNA and aminoacyl-tRNA synthetases were measured by the aminoacylation reaction using C(14)-amino acids. RESULTS: Anoxia 20 min in duration has caused a decrease in the acceptor activity of tRNA and increase in the activities of aminacyl-tRNA synthetases. Polyscias filicifolia Bailey tincture did not affect the acceptor activity of tRNA and activities aminacyl-tRNA synthetases. After 20-min anoxic perfusion with the buffer containing Polyscias filicifolia Bailey biomass tincture, the acceptor activities of tRNA increased to the control value and activities of aminacyl-tRNA synthetases reached the control value. CONCLUSIONS: The acceptor activity of tRNA from isolated pig heart decreased and activities of aminacyl-tRNA synthetases increased under anoxia. Perfusion with buffer containing tincture of Polyscias filicifolia Bailey biomass restored acceptor activities of tRNA and activities of aminacyl-tRNA synthetases.

Seasonal differences in activities of rabbit liver tRNA and aminoacyl-tRNA synthetases specific for valine and arginine under myocardial ischemia.

UNLABELLED: The objective of this study was to examine the acceptor activities of tRNA for amino acids, valine and arginine, and the activities of the corresponding aminoacyl-tRNA synthetases of normal rabbit liver and 6, 12 and 24 h after experimental myocardial ischemia in different seasons of the year. MATERIAL AND METHODS: Male rabbits (2.5-3.5 kg) were used. Acute myocardial ischemia was induced by occlusion of the left anterior descending coronary artery. tRNA and aminoacyl-tRNA synthetases were isolated from control rabbit liver and 6, 12 and 24 h after experimental myocardial ischemia in autumn (September and October) and winter (December and January). The acceptor activity of tRNA and the activity of valyl- and arginyl-tRNA synthetases were determined using 14C-labeled amino acids, valine and arginine. RESULTS: The results showed that acceptor activity of rabbit liver tRNA for valine and arginine under 6, 12 and 24 h experimental myocardial ischemia in autumn was higher by 24-35% than in winter. Activities of rabbit liver valyl- and arginyl-tRNA synthetases under 6, 12 and 24 h experimental myocardial ischemia in autumn were lower by 15-32% than in winter. No differences in the activity of tRNA and aminoacyl-tRNA synthetases between control groups of both seasons were observed. CONCLUSIONS: The experimental data suggest that acceptor activity of rabbit liver tRNA for valine and arginine and activity of valyl- and arginyl-tRNA synthetases under 6, 12 and 24 h experimental myocardial ischemia are different in autumn and winter. The decrease of acceptor activity of tRNA for valine and arginine after experimental myocardial ischemia correlates with an increase in the activity of valyl- and arginyl-tRNA synthetases both in autumn and winter. It may be part of the compensatory mechanism of the cell to keep synthesis of protein in a normal range under extreme conditions.

Effects of cadmium ions on the initial stage of translation and the cell death in mouse liver.

OBJECTIVE: To evaluate in vivo and in vitro effects of cadmium ions on the activities of mice liver tRNA(Leu)and leucyl-tRNA synthetase and on the type of liver cells death. MATERIAL AND METHODS: White laboratory mice were intoxicated by intraperitoneal injection of cadmium chloride solution (1.6 mg cadmium ions/1 kg of body weigh). Total tRNAs were isolated by adding ethanol and isopropanol into the phenol-deproteinized supernatant of mouse liver homogenate. Post-mitochondrial fraction of the liver cells was used as a source of leucyl-tRNA synthetase. Acceptor activity of tRNA(Leu)and activity of leucyl-tRNA synthetase were measured in tRNA aminoacylation reaction with [14C]-labeled leucine as a substrate. An apoptotic cell death was assessed by the TUNEL assay using in situ cell death detection kit. DNA degradation was verified by electrophoresis. RESULTS: It was determined that 2-24 hours after intoxication with sublethal dose of cadmium ions the acceptor activity of mice liver tRNA(Leu)was decreased by 43-73% as compared to control. At the same time intervals, the activity of leucyl-tRNA synthetase was reduced about 20-30%. Experiments in vitro revealed that 10-20 microM concentrations of cadmium ions suppressed the activities of mice liver tRNA(Leu)and leucyl-tRNA synthetase by 40-98%. No significant difference was observed between the number of TUNEL positive apoptotic liver cells in the control mice and 24 hours after intoxication with cadmium chloride. Electrophoresis revealed extensive degradation of nuclear DNA. CONCLUSIONS: Cadmium ions significantly reduce activities of tRNA(Leu)and leucyl-tRNA synthetase in vivo and in vitro. There is no significant difference between the number of apoptotic cells in the control liver specimens and in those after 24 hours of intoxication with cadmium chloride. In latter specimens DNA electrophoresis revealed as extensive degradation of DNA, which is characteristic to the cell necrosis.

The effects of zinc ions on activities of tRNALeu and leucyl-tRNA synthetase of mice liver.

UNLABELLED: The aim of this study was to examine the effects of zinc ions on activities of tRNA(Leu) and leucyl-tRNA synthetase of mice liver. MATERIAL AND METHODS: White laboratory mice (20-25 g) were used for study purposes. Animals were intoxicated with ions of zinc by injection of 0.15 LD50 dose of zinc sulphate solution (1.56 mg Zn2+ per 1 kg of body weight) into abdominal cavity. After 8 hours, preparations of total tRNA and aminoacyl-tRNA synthetases were isolated from the intoxicated and normal (control) mice liver. Acceptor activity of tRNA(Leu) and activity of leucyl-tRNA synthetase were determined in tRNA aminoacylation reaction using [14C]-labeled leucine. Actions of zinc ions on acceptor activity of tRNA(Leu) and on activity of leucyl-tRNA synthetase from liver of control animals in vitro were determined after addition into reaction mixture different concentrations of zinc sulphate solution. RESULTS: It was determined that acceptor activity of mice liver tRNA( Leu)8 hours after intoxication with zinc ions has increased by 29% and activity of leucyl-tRNA synthetase has increased by 20% as compared to control. Experiments in vitro have shown that 5-20 microM concentrations of zinc ions in reaction mixture stimulate the acceptor activity of mice liver tRNA(Leu)by 18-30%, higher concentration of zinc ions (40 microM)--suppresses it by 26%. The study of leucyl-tRNA synthetase activity in vitro has shown that 5-10 microM concentrations of zinc ions in reaction mixture increase activity of this enzyme by 11-16%, higher concentrations of zinc ions (20-40 microM)--decrease it by 13-21%. CONCLUSIONS: After 8-hour intoxication with zinc ions the activities of both studied components of the translation machinery--tRNA(Leu) and leucyl-tRNA synthetase were increased. It may be connected with the stimulation of zinc-binding metallothionein synthesis which is involved in the detoxification of heavy metals. Low concentrations of zinc ions in reaction mixture increase tRNA(Leu) and leucyl-tRNA synthetase activities; higher concentrations of these ions decrease activity of those components of protein synthesis system. The results show that zinc ions directly act on the activities of both components of translation machinery.

[Effects of lead ions on activities of tRNALeu and leucyl-tRNA synthetase of mouse liver]. / Svino jonu poveikis peliu kepenu tRNRLeu ir leucil-tRNR-sintetazes aktyvumui.

UNLABELLED: The objective of this study was to examine effect of lead ions on activities of mice liver tRNA(Leu) and leucyl-tRNA synthetase. MATERIAL AND METHODS: For researching white non-breed laboratory mice (20-25 g) were used. Intoxication with ions of lead was performed by injection of sublethal dose of lead acetate solution (50 mg ions of lead per 1 kg of body weight) into abdominal cavity of laboratory animals. Eight hours after intoxication from intoxicated and normal (control) mice liver preparations of tRNA and aminoacyl-tRNA synthetases were isolated. Acceptor activity of tRNA(Leu) and activity of leucyl-tRNA synthetase were determined in tRNA aminoacylation reaction using [(14)C]-labeled leucine. Actions of lead ions on acceptor activity of tRNA(Leu) and on activity of leucyl-tRNA synthetase from liver of control animals in vitro were determined after addition into reaction mixture different concentrations of lead acetate solution. RESULTS: It was determined that acceptor activity of mice liver tRNA(Leu) 8 h after intoxication with lead ions was reduced by 37 percent and activity of leucyl-tRNA synthetase was increased by 22 percent as compared to control. Experiments in vitro have shown that 10 micro M concentration of lead ions in reaction mixture stimulate acceptor activity of mice liver tRNA(Leu) by 17 percent, higher concentrations of lead ions (30-60 microM)--suppress it by 9-80 percent. The study of leucyl-tRNA synthetase activity in vitro has shown that 30 microM concentration of lead ions in reaction mixture increases activity of this enzyme by 16 percent, higher concentrations of lead ions (40-60 microM)--decrease by 17-23 percent. CONCLUSIONS: After 8 h intoxication with lead ions acceptor activity of tRNA(Leu) was decreased and activity of leucyl-tRNA synthetase was increased. It may be part of the compensatory mechanism of the cell to keep synthesis of proteins at the normal level under extreme conditions. Low concentrations of lead ions in reaction mixture increase tRNA(Leu) and leucyl-tRNA synthetase activities, higher concentrations of these ions decrease activity of those components of protein synthesis system. The results show that ions of lead directly suppress activity of both components of translation machinery.

[Seasonal differences in activity of tRNA and aminoacyl-tRNA synthetases of rabbit liver in myocardial ischemia]. / Triusiu kepenu tRNR ir aminoacil-tRNR-sintetaziu aktyvumas miokardo isemijos metu skirtingu metu laikotarpiu

UNLABELLED: The objective of this study was to examine the acceptor activities of tRNA for amino acids alanine and lysine and activities of corresponding aminoacyl-tRNA synthetases of normal rabbit liver 6, 12 and 24 h after experimental myocardial ischemia in different seasons of the year. MATERIAL AND METHODS: Male rabbits (2.5-3.5 kg) were used. Acute myocardial ischemia was induced by occlusion of the left anterior descending coronary artery. tRNA and aminoacyl-tRNA synthetases were isolated from normal (control) rabbit liver 6, 12 and 24 h after experimental myocardial ischemia in autumn (the months of September and October) and winter (the months of December and January). The acceptor activity of tRNA and activity of alanyl- and lysyl-tRNA synthetases were determined using 14C-labelled amino acids alanine and lysine. RESULTS: The results of study show that acceptor activity of rabbit liver tRNA for alanine and lysine under 6, 12 and 24 h experimental myocardial ischemia in autumn is higher by 18-52 percent than in winter. Activities of rabbit liver alanyl- and lysyl-tRNA synthetases under 6, 12 and 24 h experimental myocardial ischemia in autumn is less by 15-35 percent than in winter. No differences in activity of tRNA and aminoacyl-tRNA synthetases between normal groups of both seasons were observed. CONCLUSIONS: The experimental data suggest that there are differences in acceptor activity of rabbit liver tRNA for alanine and lysine and in activity of alanyl- and lysyl-tRNA synthetases after 6, 12 and 24 h experimental myocardial ischemia. Decreasing of acceptor activity of tRNA for alanine under experimental myocardial ischemia in winter correlate with increasing of activity of alanyl-tRNA synthetase. Decreasing of acceptor activity of tRNA for lysine under experimental myocardial ischemia correlate with increasing of lysyl-tRNA synthetase activity in both studied seasons. It may be part of the compensatory mechanism of the cell to keep synthesis of protein in normal range under extreme conditions.