Movement Disorder in Copper Toxicity Rat Model: Role of Inflammation and Apoptosis in the Corpus Striatum

Deadly excess copper

Higher eukaryotes' life is impossible without copper redox activity and, literally, every breath we take biochemically demonstrates this. However, this dependence comes at a considerable price to ensure target-oriented copper action. Thereto its uptake, distribution but also excretion are executed by specialized proteins with high affinity for the transition metal. Consequently, malfunction of copper enzymes/transporters, as is the case in hereditary Wilson disease that affects the intracellular copper transporter ATP7B, comes with serious cellular damage. One hallmark of this disease is the progressive copper accumulation, primarily in liver but also brain that becomes deadly if left untreated. Such excess copper toxicity may also result from accidental ingestion or attempted suicide. Recent research has shed new light into the cell-toxic mechanisms and primarily affected intracellular targets and processes of such excess copper that may even be exploited with respect to cancer therapy. Moreover, new therapies are currently under development to fight against deadly toxic copper.

Association of Serum Concentrations of Copper, Selenium, and Zinc with Grip Strength Based on NHANES 2013-2014

Increasing evidence has found metals to be strongly associated with muscle strength, but the correlations between serum copper (Cu), selenium (Se), and zinc (Zn) with grip strength in adult populations have not yet been established. We examined the linear and non-linear associations between these three metals and grip strength via multiple linear regression and restricted cubic spline (RCS) regression using data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014. A higher concentration of serum Cu was monotonically linked with lower grip strength [β = - 0.004 m2 (95% CI: - 0.005, - 0.002)], and serum Zn was positively associated with grip strength [β = 0.004 m2 (95% CI: 0.002, 0.006)]. We observed a positive association between serum Se and grip strength in the unadjusted model but not in covariate-adjusted models. Interestingly, the results of RCS regression showed that serum Cu had an L-shaped non-linear association with grip strength in all participants and subgroups. We further found a linear-increased trend between serum Zn and the grip strength in all participants. There were also non-linear associations that varied across different subgroups. Taken together, serum Cu and Zn were significantly associated with grip strength, while Se was not. This study offers new evidence to help formulate a reference concentration range for serum Cu and Zn.

Involvement of oxidative stress and pro-inflammatory cytokines in copper sulfate-induced depression-like disorders and abnormal neuronal morphology in mice

Epidemiological studies have implicated copper as one of the key environmental risk factors for the pathogenesis of depression. However, the precise mechanism by which copper contribute to the genesis of depression particularly the involvement of oxidative stress-driven neuroinflammation is yet to be fully investigated. Thus, this study was designed to evaluate the effects of copper sulfate (CuSO4) on depression-like behaviors and the role of oxidative stress and pro-inflammatory cytokines in mice. Forty male Swiss mice were distributed into control and three test groups (n = 10), and were treated orally with distilled water (10 mL/kg) or CuSO4 (25, 50 and 100 mg/kg) daily for 28 days. Afterwards, the tail suspension, forced swim, and sucrose splash tests were used for the detection of depression-like effects. The animals were then euthanized and the brains were processed for the estimation of biomarkers of oxidative stress and pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin-6). The histomorphological features and neuronal viability of the prefrontal cortex, hippocampus and striatum were also determined. Mice exposed to CuSO4 displayed depression-like features when compared with controls. The brain concentrations of malondialdehyde, nitrite and pro-inflammatory cytokines were elevated in CuSO4-treated mice. Mice exposed to CuSO4 also had reduced brain antioxidant status (glutathione, glutathione-s-transferase, total thiols, superoxide-dismutase and catalase), as well as altered histomorphological features, and decreased population of viable neuronal cells. These findings suggest that CuSO4 increases oxidative stress and pro-inflammatory cytokines to elicit depression-like effects in mice.

Sex-specific associations of single metal and metal mixture with handgrip strength: a cross-sectional study among Chinese adults

Metallic elements are ubiquitous in the natural environment and always collaborate to affect human health. The relationship of handgrip strength, a marker of functional ability or disability, with metal co-exposure remains vague. In this study, we aimed to investigate the effect of metal co-exposure on sex-specific handgrip strength. A total of 3594 participants (2296 men and 1298 women) aged 21 to 79 years recruited from Tongji Hospital were included in the present study. Urinary concentrations of 21 metals were measured by inductively coupled plasma mass spectrometer (ICP-MS). We used linear regression, restricted cubic spline (RCS) model, and weighted quantile sum (WQS) regression to evaluate the association of single metal as well as metal mixture with handgrip strength. After adjusting for important confounding factors, the results of linear regression showed that vanadium (V), zinc (Zn), arsenic (As), rubidium (Rb), cadmium (Cd), thallium (Tl), and uranium (U) were adversely associated with handgrip strength in men. The results of RCS showed a non-linear association between selenium (Se), silver (Ag), and nickel (Ni) with handgrip strength in women. The results of WQS regression revealed that metal co-exposure was inversely related to handgrip strength for men (β = -0.65, 95% CI: -0.98, -0.32). Cd was the critical metal in men (weighted 0.33). In conclusion, co-exposure to a higher level of metals is associated with lower handgrip strength, especially among men, and Cd may contribute most to the conjunct risk.

The concentration of potentially toxic elements (PTEs) in the coffee products: a systematic review and meta-analysis

Coffee is one of the most consumed products globally, and its contamination with potentially toxic elements (PTEs) occurs throughout the production chain and production. Therefore, the current meta-analysis study aimed to estimate the concentration of essential elements (Cu and Co) and the contamination of PTEs (Ni, Cr, Pb, As, and Cd) in coffee. The recommended databases, including PubMed, Scopus, and ScienceDirect, were investigated to collect data regarding the contamination of PTEs in coffee products from 2010 to 2021. Among 644 retrieved citations in the identification step, 34 articles were included in the meta-analysis. The pooled mean concentration of essential elements in coffee products is much higher than that of toxic elements (Co (447.106 µg/kg, 95% CI: 445.695-448.518 µg/kg) > Ni (324.175 µg/kg, 95% CI: 322.072-326.278 µg/kg) > Cu (136.171 µg/kg, 95% CI: 134.840-137.503 µg/kg) > Cr (106.865 µg/kg, 95% CI: 105.309-108.421 µg/kg) > Pb (21.027 µg/kg, 95% CI: 20.824-21.231 µg/kg) > As (3.158 µg/kg, 95% CI: 3.097-3.219 µg/kg) > Cd (0.308 µg/kg; 95% CI: 0.284-0.332 µg/kg)). Results showed high differences between pooled concentrations of all PTEs in coffee products of different countries.

Oral Administration of Copper Chloride Damages DNA, Lowers Antioxidant Defense, Alters Metabolic Status, and Inhibits Membrane Bound Enzymes in Rat Kidney

Copper (Cu) is a heavy metal that is widely used in industries and is also an essential micronutrient for living beings. However, excess Cu is toxic and human exposure to high levels of this metal results in numerous adverse health effects. We have investigated the effect of oral administration of copper chloride (CuCl₂), a Cu(II) compound, on various parameters of oxidative stress, cellular metabolism, and DNA integrity in the rat kidney. This was done to delineate the molecular mechanism of Cu(II) toxicity. Adult male rats were randomly divided into five groups. Animals in four CuCl₂-treated groups were separately administered single acute oral dose of CuCl₂ at 5, 15, 30, and 40 mg/kg body weight. Animals in the fifth group were not given CuCl₂ and served as the control. All rats were sacrificed 24 h after the dose of CuCl₂ and their kidneys removed. CuCl₂ administration led to significant alterations in enzymatic and non-enzymatic parameters of oxidative stress. It changed the activities of metabolic and membrane bound enzymes and also decreased the activities of brush border membrane enzymes. CuCl₂ treatment dose-dependently enhanced DNA damage and DNA-protein crosslinking in renal cells, when compared to the control group. The administration of CuCl₂ also resulted in marked morphological changes in the kidney, with more prominent alterations at higher doses of CuCl₂. These results clearly show that CuCl₂ impairs the antioxidant defense system resulting in oxidative damage to the kidney.

D-ribose-L-cysteine reduces oxidative stress and inflammatory cytokines to mitigate liver damage, and memory decline induced by copper sulfate in mice

BACKGROUND

Current evidences have implicated copper in amyloid aggregation that trigger the downstream oxidative stress-mediated neuroinflammation that characterized memory deterioration in patients with Alzheimer's disease (AD). Thus, this study was designed to evaluate the effect of D-Ribose-L-Cysteine (DRLC), a potent antioxidant agent, on copper sulfate (CuSO₄)-induced memory deterioration and the biochemical mechanisms underpinning its action in mice.

METHODS

Male Swiss mice were randomly distributed into 5 groups (n = 10/group). Mice in group 1 were given distilled water (control), group 2 CuSO₄ (100 mg/kg) while groups 3-5 were pretreated with CuSO₄ (100 mg/kg) 30 min before administration of DRLC (10, 25 and 50 mg/kg). Treatments were given through oral gavage, daily for 28 days. Memory function was evaluated on day 28 using Y-maze test. The isolated liver and brain tissues were then processed for oxidative stress biomarkers, and proinflammatory cytokines [tumor necrosis factor- α (TNF-α) and interleukin-6)] assays. Brian acetylcholinesterase (AChE) and liver enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were also determined.

RESULTS

DRLC reversed memory impairment and dysregulated levels of malondialdehyde, glutathione, nitrite and glutathione S-transferase in the liver and brain tissues of mice pretreated with CuSO₄. The increased proinflammatory cytokines concentrations in the liver and brain tissues of mice pretreated with CuSO₄ were reduced by DRLC. The elevated brain AChE and liver enzymes activities induced by CuSO₄ were also reduced by DRLC.

CONCLUSION

Taken together, these findings suggest that DRLC attenuates CuSO₄-induced memory dysfunctions in mice through enhancement of antioxidative pathway, inhibition of pro-inflammatory cytokines and augmentation of liver function.

Food Contamination: An Unexplored Possible Link between Dietary Habits and Parkinson’s Disease

Importance of a healthy lifestyle in maintaining the population’s well-being and health, especially in terms of balanced nutrition, is well known. Food choice of and dieting habits could impact disease management, which is especially true for Parkinson’s disease (PD). However, nowadays, it is not that simple to maintain a balance in nutrition, and the idea of a healthy diet tends to fade as the consequence of a western lifestyle. This should not only be dealt with in the context of food choice, but also from an environmental point of view. What we put into our bodies is strictly related to the quality of ecosystems we live in. For these reasons, attention should be directed to all the pollutants, which in many cases, we unknowingly ingest. It will be necessary to explore the interaction between food and environment, since human activity also influences the raw materials destined for consumption. This awareness can be achieved by means of an innovative scientific approach, which involves the use of new models, in order to overcome the traditional scientific investigations included in the study of Parkinson’s disease.

Chrysin and flunixin meglumine mitigate overloaded copper-induced testicular and spermatological damages via modulation of oxidative stress and apoptosis in rats

This study aimed to evaluate the possible protective actions of chrysin and flunixine meglumine on testicular and spermatological injuries experimentally stimulated by copper. We separated 36 male Sprague-Dawley rats into six equal groups: control, chrysin, flunixine meglumine, copper, copper +chrysin and copper +flunixine meglumine. Chrysin (50 mg/kg/bw/po), flunixine meglumine (2.2 mg/kg/bw/ip) and copper (500 mg/kg/bw/po) were administered day to day for 21 days. Copper administration caused significant morphological, physiological and biochemical alterations compared to the control group, which are as follows: production of oxidative stress, thanks to rise in testis lipid peroxidation and fall in antioxidant enzyme concentrations, decrease in sperm quality and increase in morphologic sperm abnormalities, suppression of spermatogenesis and prominent alterations in the testis histomorphology and induction of apoptosis in the testis tissues. On the other hand, compared to the copper group, treatment with chrysin or flunixine meglumine significantly attenuated these alterations. In conclusion, chrysin and flunixine meglumine have benefits such as antioxidant, antiapoptotic and anti-inflammatory against copper-induced testicular and spermatological damages in rats via the modulation of oxidative stress and apoptosis. Consequently, chrysin is a natural product which has comparable therapeutic actions to flunixine meglumine on the male reproductive system.

Neuropsychiatric Manifestations of Wilson Disease: Correlation with MRI and Glutamate Excitotoxicity

This study aims to identify neuropsychiatric manifestations in neurological Wilson disease (NWD), and their correlation with MRI changes and glutamate excitotoxicity. Forty-three consecutive patients with NWD from a tertiary care teaching hospital were evaluated prospectively who fulfilled the inclusion criteria. The neuropsychiatric evaluation was done using Neuropsychiatric Inventory (NPI) battery that assesses 12 domains including delusion, hallucination, agitation/aggression, dysphoria/depression, anxiety, euphoria, apathy, disinhibition, irritability, aberrant motor activity, appetite change, and abnormal nighttime behavior. Cranial MRI was done using a 3 T machine, and locations of signal changes were noted including the total number of MRI lesions. Serum glutamate level was measured by a fluorescence microplate reader. Abnormal NPI in various domains and total NPI scores were correlated with MRI lesions, serum and urinary copper, and glutamate level. The median age of the patients was 16 years. Forty-one (48.8%) patients had cognitive impairment and 37 (86%) had movement disorder. Neurobehavioral abnormality was detected in all-commonest being agitation (90.7%) followed by appetite change (81.4%), elation (74.4%), irritability (69.8%), anxiety (67.4%), depression (65.1%), apathy (44.2%), night time abnormal behavior (32.6%), aberrant motor behavior (20.9%), delusions (16.3%), and hallucination (18.6%). The thalamic lesion was associated with depression, globus pallidus with depression and anxiety, caudate with anxiety and agitation, brainstem with irritability, and frontal cortex with apathy. Serum glutamate level was higher in NWD. NPI sum score correlated with MRI load and glutamate level. Varying severity of neurobehavioral abnormalities are common in the patients with NWD and correlate with the location of MRI lesion and glutamate level.

Copper chloride inhibits brush border membrane enzymes, alters antioxidant and metabolic status and damages DNA in rat intestine: a dose-dependent study

Copper (Cu) is an extensively used heavy metal and an indispensible micronutrient for living beings. However, Cu is also toxic and exerts multiple adverse health effects when humans are exposed to high levels of this metal. We have examined the effect of single acute oral dose of copper chloride (CuCl₂) on parameters of oxidative stress, cellular metabolism, membrane and DNA damage in rat intestine. Adult male Wistar rats were divided into four groups and separately administered a single oral dose of 5, 15, 30 and 40 mg CuCl₂/kg body weight. Rats not administered CuCl₂ served as the control. Oral administration of CuCl₂ led to significant alterations in the activities of metabolic and membrane-bound enzymes; brush border enzymes were inhibited by 45-75% relative to the control set. Inhibition of antioxidant enzymes diminished the metal-reducing and free radical quenching ability of the cells. Oxidative damage caused cellular oxidation of thiols, proteins and lipids. Diphenylamine and comet assays showed that CuCl₂ treatment enhanced DNA damage while DNA-protein crosslinking was also increased in the intestinal cells. Examination of stained sections showed that CuCl₂ treatment led to marked histological changes in the intestine. All the changes seen were in a CuCl₂ dose-dependent manner with more prominent alterations at higher doses of CuCl₂. These results clearly show that oral administration of CuCl₂ results in oxidative damage to the intestine which can impair its digestive and absorptive functions.

Flavonoids: Potential Candidates for the Treatment of Neurodegenerative Disorders

Neurodegenerative disorders, such as Parkinson's disease (PD), Alzheimer's disease (AD), Amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD), are the most concerning disorders due to the lack of effective therapy and dramatic rise in affected cases. Although these disorders have diverse clinical manifestations, they all share a common cellular stress response. These cellular stress responses including neuroinflammation, oxidative stress, proteotoxicity, and endoplasmic reticulum (ER)-stress, which combats with stress conditions. Environmental stress/toxicity weakened the cellular stress response which results in cell damage. Small molecules, such as flavonoids, could reduce cellular stress and have gained much attention in recent years. Evidence has shown the potential use of flavonoids in several ways, such as antioxidants, anti-inflammatory, and anti-apoptotic, yet their mechanism is still elusive. This review provides an insight into the potential role of flavonoids against cellular stress response that prevent the pathogenesis of neurodegenerative disorders.