Influence of exercise and ethanol on cholinesterase activity and lipid peroxidation in blood and brain regions of rat

Does butyrylcholinesterase mediate exercise-induced and meal-induced suppression in acylated ghrelin?

Ample evidence supports the notion that an acute bout of aerobic exercise and meal consumption reduces acylated ghrelin concentration. However, the mechanisms by which this exercise- and meal-induced suppression of acylated ghrelin occurs in humans is unknown. This study aimed to examine the concentration of butyrylcholinesterase (BChE), an enzyme responsible for hydrolysing ghrelin and other appetite-related hormones in response to a single bout of running and a standardised meal in young, healthy men. Thirty-three men (aged 23 ± 2 years, mean ± standard deviation) underwent two (exercise and meal conditions) 2-h laboratory-based experiments. In the exercise condition, all participants ran for 30 min at 70% of the maximum oxygen uptake (0930-1000) and rested until 1130. In the meal condition, participants reported to the laboratory at 0930 and rested until 1000. Subsequently, they consumed a standardised meal (1000-1015) and rested until 1130. Blood samples were collected at baseline (0930), 1000, 1030, 1100 and 1130. BChE concentration was not altered in both the exercise and meal conditions (p > 0.05). However, acylated ghrelin was suppressed after exercise (p < 0.05) and meal consumption (p < 0.05). There was no association between the change in BChE concentration and the change in acylated ghrelin before and after exercise (p = 0.571). Although des-acylated ghrelin concentration did not change during exercise (p > 0.05), it decreased after meal consumption (p < 0.05). These findings suggest that BChE may not be involved in the suppression of acylated ghrelin after exercise and meal consumption.

Resistance training and Urtica dioica increase neurotrophin levels and improve cognitive function by increasing age in the hippocampus of rats

INTRODUCTION

Inflammation and oxidative stress are two major factors in accelerating brain aging. Consumption of some traditional herbs with antioxidant and anti-inflammatory properties such as Urtica dioica extract (Ud) and resistance training (RT) may be effective in controlling premature aging and memory impairment. Therefore, we hypothesized that the combined effect of RT and Ud might play an essential role in preventing memory disorders and hippocampal tissue changes caused by increasing age in rats.

METHODS

28 male Wistar rats (24-week) were divided into 4-groups (n = 7): control (C), Ud, RT, and Ud+RT. RT groups were trained for five weeks, and Ud extract in the 0.0166 w/v concentration (50 mg/kg, oral/daily) was administered. We also examined the effects of RT and Ud on the behavioral (memory and learning), histological (the morphological changes in the dentate gyrus), and transcript aspects of hippocampal tissue.

RESULTS

Aging led to karyopyknosis in the hippocampal tissue, which was alleviated by RT and Ud supplementation. RT and Ud were accompanied by increased GPx, GSH, GAP-43, and decreased CAP-1 levels in the hippocampus. Moreover, RT and Ud led to increased NGF, BDNF, and GAP-43 levels, decreased MDA, and protection of hippocampal tissue from karyopyknosis, which was associated with cognitive improvement. However, these interventions had no significant effect on the hippocampal levels of IL-1β, SOD, and CAT.

CONCLUSIONS

These findings suggest that increasing age decreases hippocampal NGF, BDNF, and GAP-43 levels and impairs cognition, which may be reversed by regular RT and Ud extract.

Combination effect of exercise training and eugenol supplementation on the hippocampus apoptosis induced by chlorpyrifos

The aim of this study was to investigate the combination effect of exercise training and eugenol supplementation on the hippocampus apoptosis induced by CPF. 64 adult male albino rats were randomly selected and devided into eight groups of eight including: control, exercise (EXE), chlorpyrifos (CPF), Control + Oil (Co + Oil), Control + DMSO (Co + DMSO), chlorpyrifos + eugenol (CPF + Sup), chlorpyrifos + exercise (CPF + Exe) and, chlorpyrifos + exercise + eugenol (CPF + Exe + Eu). Four experimental groups received intraperitoneal injection (5 days a week) of 3.0 mg/kg body weight CPF in DMSO for 6 consecutive weeks. The exercise groups performed aerobic 5 days per week over 4 weeks. Eugenol were administered by gavage. Finally, the animals were sacrificed using CO₂ gas (a half of the rats were anesthetized with ketamine and xylazine and then perfused) to evaluate hippocampus histology and parameters. The results of this study showed that CPF injection significantly decreased BDNF, AChE and ATP in CA1 area of the hippocampus (p ˂ 0.05). Also, CA1 apoptosis by tunnel assay, it was found that CPF receiving groups with different dosage, showed a significant increase compared to other groups, which was confirmed by increasing cytochrome C and procaspase-3 in CPF groups (p ˂ 0.05). The result of this study show that 4 weeks of exercise training and eugenol supplementation does not improve the destructive effects of CPF in CA1 area of the hippocampus. As a result, it is recommended that future studies longer periods for treatment with exercise and eugenol supplementation.

The effect of regular exercise on antioxidant enzyme activities and lipid peroxidation levels in both hippocampi after occluding one carotid in rat

Regular exercise has beneficial effects on cerebrovascular diseases; however, its biochemical mechanisms are not fully known. The purpose of this study was to determine antioxidant enzyme activities and lipid peroxidation of both hippocampi after applying exercise followed by occluding one common carotid. Wistar rats were divided into four groups of control, exercise, hypoperfusion and exercise-hypoperfusion (exe-hypo). In the exercise and exe-hypo groups, the rats were forced to run on a treadmill for 1 h a day for 2 months. The right common carotid of the animals in the (exe-hypo) group was occluded after the cessation of exercise. Surgery without occlusion of the carotid was applied on the control (without exercise) and exercise groups. All animals were sacrificed 1 and 24 h after surgery. The levels of malondialdehyde (MDA) and antioxidant enzyme activities in the hippocampi were measured. A significant interaction was observed between the exercise and hypoperfusion in both hippocampi (p<0.05). In comparison with the control group, there was significant elevation of catalase activity in the right and left hippocampus of the hypo group at 24 h (p<0.0001). Regarding the differences between the hemispheres, there was a significant increase in MDA and decrease in catalase activity in the left hippocampus in hypoperfusion group, but the exercise in the exe-hypo group succeeded in abolishing these alterations which were caused by hypoperfusion, This study shows that exercise pre-conditioning prevents some alterations in brain oxidant-antioxidant status which are induced by cerebral hypoperfusion. Further studies are needed in order to clarify the mechanism of exercise.

Exercising the worry away: how inflammation, oxidative and nitrogen stress mediates the beneficial effect of physical activity on anxiety disorder symptoms and behaviours

Regular physical activity exerts positive effects on anxiety disorder symptoms, although the biological mechanisms underpinning this effect are incompletely understood. Numerous lines of evidence support inflammation and oxidative and nitrogen stress (O&NS) as important in the pathogenesis of mood and anxiety disorders, and physical activity is known to influence these same pathways. This paper reviews the inter-relationships between anxiety disorders, physical activity and inflammation and O&NS, to explore whether modulation of inflammation and O&NS may in part underpin the positive effect of physical activity on anxiety disorders. Numerous studies support the notion that physical activity operates as an anti-inflammatory and anti-O&NS agent which potentially exerts positive effects on neuroplasticity, the expression of neurotrophins and normal neuronal functions. These effects may therefore influence the expression and evolution of anxiety disorders. Further exploration of this area may elicit a deeper understanding of the pathogenesis of anxiety disorders, and inform the development of integrated programmes including PA specifically suited to the treatment and prevention of anxiety disorders and symptoms.

Diabetes impairs exercise training-associated thioredoxin response and glutathione status in rat brain

Regular exercise plays an important preventive and therapeutic role in oxidative stress-associated diseases such as diabetes and its complications. Thiol antioxidants including thioredoxin (TRX) and glutathione (GSH) have a crucial role in controlling cellular redox status. In this study, the effects of 8 wk of exercise training on brain TRX and GSH systems, and antioxidant enzymes were tested in rats with or without streptozotocin-induced diabetes. We found that in untrained animals, the levels of TRX-1 (TRX1) protein and activity, and thioredoxin-interacting protein (TXNip) were similar in diabetic and nondiabetic animals. Exercise training, however, increased TRX1 protein in nondiabetic animals without affecting TXNip levels, whereas diabetes inhibited the effect of training on TRX1 protein and also increased TXNip mRNA. In addition, the proportion of oxidized glutathione (GSSG) to total GSH was increased in animals with diabetes, indicating altered redox status and possibly increased oxidative stress. Glutathione peroxidase-1 (GPX1) levels were not affected by diabetes or exercise training, although diabetes increased total GPX activity. Both diabetes and exercise training decreased glutathione reductase (GRD) activity and cytosolic superoxide dismutase (Cu,Zn-SOD) levels. Nevertheless, diabetes or training had no effect on Cu,Zn-SOD mRNA, Mn-SOD protein, total SOD activity, or catalase mRNA, protein, or activity. Our findings suggest that exercise training increases TRX1 levels in brain without a concomitant rise in TXNip, and that experimental diabetes is associated with an incomplete TRX response to training. Increased oxidative stress may be both a cause and a consequence of perturbed antioxidant defenses in the diabetic brain.

Acute exhaustive exercise does not alter lipid peroxidation levels and antioxidant enzyme activities in rat hippocampus, prefrontal cortex and striatum

Although regular physical exercise is beneficial to the body, it is well known that exhaustive exercise causes oxidative stress in muscle. Recent studies suggest that regular moderate physical exercise has the beneficial effects on brain. However, there is little information regarding whether or not exhaustive exercise could generate oxidative stress in brain and the findings are conflicting. The aim of this study was to investigate the effects of exhaustive exercise on thiobarbituric acid reactive substances, as an indicator of lipid peroxidation, in the hippocampus, prefrontal cortex and striatum. Additionally we examined antioxidant enzymes activities, superoxide dismutase and glutathione peroxidase, to assess the effects of reactive oxygen species. Exhaustive exercise did not change superoxide dismutase and glutathione peroxidase enzyme activities and thiobarbituric acid reactive substances levels neither immediately (0 min) nor at 3, 6, 12, 24 and 48 h after the cessation of exercise in the brain. These results indicate that acute exhaustive exercise may not cause significant lipid peroxidation in the hippocampus, prefrontal cortex and striatum during the post-exercise period.

Interaction of pyridostigmine and physical stress on antioxidant defense system in skeletal muscle of mice

Pyridostigmine bromide (PB), a reversible anticholinesterase drug, had been used against possible nerve gas exposure during the Persian Gulf War. The Gulf War veterans used PB and they were under physical stress. This study investigated the delayed and interactive effects of pyridostigmine and physical stress on the antioxidant defense system in triceps muscle of mice. Male NIH Swiss mice were divided into four groups and treated as follows: sedentary control; pyridostigmine (1.2 mg kg(-1) p.o.); exercise; and PB plus exercise. Mice were exercised for 10 weeks, but PB was administered daily during the 5th and 6th weeks. Mice were sacrificed 24 h after the last treatments and the triceps muscle was isolated and analyzed. There was a significant increase in total superoxide dismutase (CuZn-SOD + Mn-SOD) activity (141% of control) with PB plus exercise, suggesting that any influx of superoxide anions was scavenged efficiently. The Mn-SOD enzyme protein levels were reduced significantly (63% of control) by PB plus exercise. Catalase enzyme protein levels were increased significantly by exercise (132% of control) as well as by PB plus exercise (139% of control). Glutathione levels were increased significantly by exercise alone (123% of control). Pyridostigmine bromide plus exercise significantly increased the malondialdehyde concentration (124% of control) in the triceps muscle, indicating an oxidative stress response of the combination. The data indicate that a combination of PB ingestion and exercise training significantly altered the antioxidant enzyme activities, enzyme protein levels and lipid peroxidation, leading to oxidative injury. Physical stress amplified the delayed effects of PB in the skeletal muscle of mice.

Effects of combined exposure to aluminium and ethanol on food intake, motor behaviour and a few biochemical parameters in pubertal rats

Combined daily administration of aluminium chloride (260 mg/kg, oral) and ethanol (2 g/kg, oral), to pubertal male rats for 30 days was found to significantly decrease food intake, body weight gain and serum protein levels. Spontaneous motor activity and rota-rod motor coordination were also significantly impaired. Acetylcholinesterase activity was significantly diminished in the cerebrum and cerebellum. The results obtained in the present study are suggestive of a potentiation of cholinotoxic effects of the two compounds when administered together. Thus, when combined, ethanol may increase pubertal rat's susceptibility to the toxic effects of aluminium.

Interactive and delayed effects of pyridostigmine and physical stress on biochemical and histological changes in peripheral tissues of mice

Gulf War veterans were taking pyridostigmine orally against possible exposure to nerve agents as well as being under physical stress. This study was designed to investigate the delayed effects of pyridostigmine and treadmill exercise on cholinesterase activity, lipid peroxidation and histology of peripheral tissues of mice. Male NIH Swiss mice were divided into four groups of 15 animals each and treated as follows: sedentary control; exercise training for 10 weeks; pyridostigmine (1.2 mg kg(-1), p.o.) for 2 weeks during weeks 5 and 6; and pyridostigmine plus exercise training. The mice were sacrificed 24 h after the last exercise, and blood, triceps muscle and sciatic nerve were isolated and analyzed. The group treated with pyridostigmine alone showed decreased plasma butyrylcholinesterase (BChE) activity (87% of control), whereas pyridostigmine plus exercise significantly decreased the BChE activity (79% of control), indicating an interactive effect of the combination. Acetylcholinesterase (AChE) activity did not alter significantly in red blood cells, platelets or sciatic nerve with either of the treatments. However, AChE activity in triceps muscle decreased significantly (78% of control) in the group treated with pyridostigmine plus exercise. Creatine phosphokinase activity in plasma increased slightly (compared to control, pyridostigmine or exercise group) in mice treated with pyridostigmine plus exercise, which may be indicative of perturbation in the integrity of the skeletal muscle due to combination. However, there were no obvious histological abnormalities in the triceps muscle detected between experimental and control groups. Interaction of pyridostigmine and exercise significantly increased the concentration of the end product of lipid peroxidation (malondialdehyde) (124% of control) in triceps muscle, indicating an oxidative stress response of the combination. These results indicate that physical stress enhanced the delayed toxic effects of a subchronic oral dose of pyridostigmine primarily in the skeletal muscle of mice.

Parallel regional quantification of choline acetyltransferase and cholinesterase activity in the central nervous system of an invertebrate (Sepia officinalis)

The present study describes (i) a procedure to dissect the central nervous system of the cuttlefish (Cephalopod) into ten, functionally distinct, anatomical regions of interest and (ii) the parallel measurement of acetylcholine synthesis (choline acetyltransferase) and degradation (cholinesterase) activities. Both aspects (dissection and parallel quantification of acetylcholine synthesis and degradation) could be of great importance for quantitative regional studies in neurochemistry in this animal model, it is interesting to study the cellular and molecular mechanisms involved in learning and aging processes. The parallel quantification of acetylcholine synthesis and degradation applicable to any animal model is pivotal since both enzymes are essential for the cholinergic neurotransmission and may be differentially modulated by specific functions such as learning and aging processes. Furthermore, since choline acetyltransferase and cholinesterase show different localization into the brain, their parallel quantification may underlie the involvement of cholinesterase in non-cholinergic functions, which remain unclear throughout the animal kingdom.

Effect of exercise training and chronic ethanol ingestion on cholinesterase activity and lipid peroxidation in blood and brain regions of rat

1. This study examines the effects of exercise training and chronic ethanol consumption on cholinesterase activity and its relationship to lipid peroxidation in blood and brain regions of rat. 2. Exercise training (6.5 weeks) decreased acetylcholinesterase (AChE) activity significantly (64% of control) in hypothalamus and increased AChE activity in cerebral cortex (149% of control), whereas, malondialdehyde (MDA) levels increased in hypothalamus (129% of control) and decreased in cortex, striatum, and cerebellum (50%, 69% and 75% of control), respectively. 3. Chronic ethanol ingestion (2.0 gm/kg, p.o. for 6.5 weeks) significantly increased butyrylcholinesterase (BuChE) activity in plasma (136% of control) and decreased AChE activity in hypothalamus (63% of control), whereas, MDA levels increased in hypothalamus, cortex, and plasma (140%, 130% and 220% of control), respectively. 4. The combination significantly increased BuChE activity (173% of control) in plasma and decreased AChE activity (71% of control) in hypothalamus and (57% of control) in cerebellum, whereas, MDA levels increased in hypothalamus, cerebellum, medulla and plasma (134%, 128%, 140% and 309% of control), respectively. 5. Exercise training, chronic ethanol ingestion, and combination selectively inhibited hypothalamic AChE and the inhibition was correlated with increased lipid peroxidation (r = 0.11, 0.41 and 0.45) which may perturb hypothalamic function. The combination enhanced the peripheral stress response by increasing plasma BuChE activity and lipid peroxidation.