Subchronic methionine load induces oxidative stress and provokes biochemical and histological changes in the rat liver tissue.

The aim of this study was to assess the effects of L-cysteine (Cys) (7 mg/kg) and N-acetyl-L-cysteine (NAC) (50 mg/kg) in the rat liver caused by subchronic i.p. application of methionine (Met) (0.8 mmol/kg) during 21 days. Malondialdehyde (MDA) concentration, glutathione content (GSH), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and acetylcholinesterase (AchE) activities were determined in the liver tissue and activities of liver enzymes (AST, ALT, ALP, and GGT) and concentrations of total proteins and albumin were determinated in plasma/serum. Catalase, superoxide dismutase, and acetylcholinesterase activities were increased by Cys and NAC. Met caused periportal mononuclear infiltration and rare focal necrosis of hepatocytes. In Cys- and NAC-supplemented groups, intracellular edema and microvesicular fatty changes without necrosis were noticed. We observed decrease of AST, ALT, and ALP activity in the methionine-treated group. Our results indicate that Cys and NAC application can increase activity of antioxidative enzymes and prevent intensive histological changes in liver in condition of subchronic methionine exposure.

The role of oxidative stress as a risk factor for rupture of posterior inferior cerebellar artery aneurysms.

Cerebral aneurysm affects 2-5% of the population and posterior inferior cerebellar artery (PICA) aneurysms account for 1-3% of all intracranial aneurysms. Oxidative stress is known to contribute to the progression of cerebrovascular disease and it may be increased by inflammation, a key contributor to cerebral aneurysm development and rupture. The aim of this study was to examine the role of overall oxidative stress as a risk factor for rupture of PICA aneurysms. This study included 29 patients with PICA aneurysms: 18 ruptured and 11 unruptured. We determined catalase, malondialdehyde, myeloperoxidase and carbonyl groups in homogenates of excised aneurysm tissue after surgery and plasma levels of C reactive protein and fibrinogen. The patient's age and sex, size of aneurysms, multiplicity, history of previous subarachnoidal hemorrhage (SAH) and risk factors for oxidative stress such as hypertension and smoking were compared between unruptured and ruptured aneurysms. Maximal diameter and SAH history were independent predictors for aneurysm rupture. Activity of catalase was decreased while activity of myeloperoxidase, levels of malondialdehyde, carbonyl groups in aneurismal tissue and plasma levels of C reactive protein and fibrinogen were increased in patients with ruptured aneurysms. Plasma levels of C reactive protein and fibrinogen showed positive correlation with myeloperoxidase, malondialdehyde, carbonyl groups and PHASES score and negative correlation with catalase. These findings suggest that oxidative stress may contribute importantly to rupture of PICA aneurysms and plasma levels of C reactive protein and fibrinogen correlate with oxidative stress markers in tissue.

Fish oil supplementation improved liver phospholipids fatty acid composition and parameters of oxidative stress in male Wistar rats.

In the present study, we examined the effects of fish oil supplementation in 3 months old male Wistar rats on changes in plasma and liver lipid metabolism and oxidative stress parameters. Twenty Wistar rats were randomly divided into two groups of ten animals: control group and intervention group, treated for 6 weeks with fish oil capsules containing 45 mg eicosapentanoic acid and 30 mg docosahexanoic acid. After intervention, biochemical parameters in plasma [triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and total cholesterol, urea, creatinine and uric acid], fatty acid (FAs) profile of liver phospholipids and parameters of oxidative stress in liver [activity of catalase, superoxide dismutase and paraoxonase (PON1), concentration of nitrites, lipid peroxidation (LPO), free thiol (SH) groups and lactate dehydrogenase (LDH) izoenzymes were determined. Treatment with fish oil improved FAs profile of liver phospholipids, increasing n-3 FAs and decreasing n-6/n-3 ratio. Significant decrease in plasma TG and LDL concentration, and increase in the level of HDL and uric acid were found in intervention group at the end of the study. Catalase activity, LPO, and nitrites concentration in liver were significantly decreased, after the supplementation, together with elevated PON1 activity. Applied treatment significantly improved plasma lipid profile, liver FAs composition and parameters of oxidative stress in male Wistar rats.

Involvement of cholinesterases in oxidative stress induced by chlorpyrifos in the brain of Japanese quail.

Chlorpyrifos is a widely used organophosphate pesticide (OP). In birds and mammals OP exhibits a toxic effect via inhibition of cholinesterases [acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)] and through oxidative/nitrosative stress. In this study, the influence of chlorpyrifos on cholinesterase activity, parameters of oxidative stress [malondialdehyde (MDA); glutathione (GSH); superoxide dismutase (SOD); nitrite concentration (NO2-); hydrogen peroxide (H2O2)], and inflammatory parameter [activity of myeloperoxidase (MPO)] in the brain of Japanese quail (Coturnix japanica) was examined. The study was conducted on a total of 60 male Japanese quails (one control and 5 experimental groups, n = 10), 3 to 4 wk old. Quails were administered by gavage chlorpyrifos (CPF) for 7 consecutive da at doses of 0.375 mg/kg BW, 0.75 mg/kg BW, 1.5 mg/kg BW, 3 mg/kg BW, and 6 mg/kg BW. Our studies have shown that all doses of CPF significantly inhibited both cholinesterases in brain: AChE from 22.74 to 37.83% and BChE from 19.53 to 61.9%, and that inhibition was dose dependent. Also, CPF has led to an increase in the concentration of MDA, GSH, NO2-, and H2O2 and activity of SOD and MPO. Overall, these results support the hypothesis that CPF causes oxidative stress and inflammatory response. This research was carried out on quails because there is hardly any or not enough data about the neurotoxic effect of CPF and especially about its influence on oxidative stress in birds. This study is highly important because we are witnessing massive avian mortality in certain countries due to pesticides.

Oxidative stress and DNA damage in horses naturally infected with Theileria equi.

The aim of this study was to determine the concentrations of oxidative stress parameters and DNA damage in horses infected by Theileria equi. Initial screening of 110 horses with duplex PCR enabled the selection of 30 infected horses with T. equi and 30 free of infection (control). Specimens from the 60 horses were further analysed by determining the following oxidative stress parameters: extent of haemolysis (EH), plasma free haemoglobin (PHb), catalase (CAT), Cu,Zn superoxide dismutase (SOD1), paraoxonase (PON1), nitrite (NO2-), total nitrate and nitrite (NOx), malondialdehyde (MDA) and free thiol groups (-SH). In addition, relative distribution of lactate dehydrogenase (LDH1-LDH5) activity and the DNA-damaging effects of T. equi infection were evaluated. Compared to control horses, horses infected with T. equi had significantly higher SOD1 activities (P <0.05) and PHb (P <0.01), NO2- (P <0.001), NOx (P <0.05) and MDA concentrations (P <0.001), and significantly lower EH (P <0.001), CAT (P <0.01) and PON1 (P <0.001) activities, and thiol group concentrations (P <0.05). The comet assay demonstrated significantly increased DNA damage in T. equi infected cells compared to non-infected cells (P <0.001). Infected horses had significantly increased LDH5 isoenzyme activities (P <0.05). There was higher production of ROS/RNS in T. equi-infected horses, which resulted in changes in osmotic fragility, damage to lipids, proteins and DNA, haemolysis and hepatocellular damage. Oxidative stress in horses naturally infected with T. equi could contribute to the pathogenesis of the infection.

CaNa2EDTA chelation attenuates cell damage in workers exposed to lead--a pilot study.

Lead induced oxidative cellular damage and long-term persistence of associated adverse effects increases risk of late-onset diseases. CaNa2EDTA chelation is known to remove contaminating metals and to reduce free radical production. The objective was to investigate the impact of chelation therapy on modulation of lead induced cellular damage, restoration of altered enzyme activities and lipid homeostasis in peripheral blood of workers exposed to lead, by comparing the selected biomarkers obtained prior and after five-day CaNa2EDTA chelation intervention. The group of smelting factory workers diagnosed with lead intoxication and current lead exposure 5.8 ± 1.2 years were administered five-day CaNa2EDTA chelation. Elevated baseline activity of antioxidant enzymes Cu, Zn-SOD and CAT as well as depleted thiols and increased protein degradation products-carbonyl groups and nitrites, pointing to Pb induced oxidative damage, were restored toward normal values following the treatment. Lead showed inhibitor potency on both RBC AChE and BChE in exposed workers, and chelation re-established the activity of BChE, while RBC AChE remained unaffected. Also, genotoxic effect of lead detected in peripheral blood lymphocytes was significantly decreased after therapy, exhibiting 18.9% DNA damage reduction. Administration of chelation reversed the depressed activity of serum PON 1 and significantly decreased lipid peroxidation detected by the post-chelation reduction of MDA levels. Lactate dehydrogenase LDH1-5 isoenzymes levels showed evident but no significant trend of restoring toward normal control values following chelation. CaNa2EDTA chelation ameliorates the alterations linked with Pb mediated oxidative stress, indicating possible benefits in reducing health risks associated with increased oxidative damage in lead exposed populations.

[Ear acupuncture has a hypotonic effect on the gastrointestinal tract]. / Hipotoni efekat aurikuloakupunkture na gastrointestinalni trakt.

The effect of auricular acupuncture (AAP) on the motility and tone of gastrointestinal tract was investigated in 60 patients, by comparison of the width of corpus and antrum of the stomach, as well as duodenum before and after the application of AAP. The obtained results showed that the effects of AAP and usual drugs were equal. The fact that AAP was applied without any side effects and contraindications pointed to the possibility of its wider application in clinical practice.