Copper Poisoning, a Deadly Hazard for Sheep

Role of copper chelating agents: between old applications and new perspectives in neuroscience

The role of copper element has been an increasingly relevant topic in recent years in the fields of human and animal health, for both the study of new drugs and innovative food and feed supplements. This metal plays an important role in the central nervous system, where it is associated with glutamatergic signaling, and it is widely involved in inflammatory processes. Thus, diseases involving copper (II) dyshomeostasis often have neurological symptoms, as exemplified by Alzheimer's and other diseases (such as Parkinson's and Wilson's diseases). Moreover, imbalanced copper ion concentrations have also been associated with diabetes and certain types of cancer, including glioma. In this paper, we propose a comprehensive overview of recent results that show the importance of these metal ions in several pathologies, mainly Alzheimer's disease, through the lens of the development and use of copper chelators as research compounds and potential therapeutics if included in multi-target hybrid drugs. Seeing how copper homeostasis is important for the well-being of animals as well as humans, we shortly describe the state of the art regarding the effects of copper and its chelators in agriculture, livestock rearing, and aquaculture, as ingredients for the formulation of feed supplements as well as to prevent the effects of pollution on animal productions.

Copper Toxicity in Animals: A Review

Copper is an essential trace element in animals and humans. However, excessive intake of copper can cause copper ions to accumulate in tissues and organs of animals, leading to copper toxicity. Copper ions induce apoptosis and autophagy through oxidative stress-mediated mitochondrial dysfunction. In addition, copper induces cell death by targeting lipoylated tricarboxylic acid (TCA) cycling proteins, termed cuproptosis. In recent years, copper cytotoxicity studies have attracted attention. In addition, the number of cases of copper toxicity in animals has been increasing over the past years due to environmental pollution and overdose from copper feed supplements. Therefore, a comprehensive understanding of copper toxicity and the metabolism of copper ions can aid in devising strategies for preventing copper toxicity. This review introduces the tissue and organ toxicity and cytotoxicity caused by copper toxicity and reviews the metabolism of copper ions in tissues, organs, and cells. The paper also reviews the clinical cases and animal experiments of copper toxicity in recent years. Finally, the preventive and curative measures for copper toxicity and the future challenges are also discussed. The general objective of this paper is to provide a reliable reference for copper toxicity prevention.

Copper-induced pro-apoptotic response and its alleviation by Quercetin through autophagic modulation in HEPG2 cells

BACKGROUND

Recent studies indicated that the liver is susceptible to Cu-induced stress as it stores and distributes the metal to other cellular organelles. To counteract the hepatocytic damage, a known polyphenol, quercetin, was employed for its remarkable antioxidant properties. Thus, the study aimed to assess quercetin's potency against Cu-induced toxicity in HEPG2 cells.

METHODS

The cellular viability of HEPG2 cells was carried out by MTT assay. All the cellular experiments were divided into control, Cu 100 µM, Cu 100 µM (with Q μM), Cu 300 µM, Cu 300 µM (with Q 50 nM), and only quercetin (50 nM). Following this, reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) were evaluated in co-exposure studies. Moreover, rhodamine-123, Hoechst stain, monodansylcadaverine (MDC), and acridine orange (AO) stain were used to visualize the morphological changes under bright field and fluorescent microscopy. Subsequently, western blotting was adopted to determine the expression level of apoptotic and autophagic marker proteins.

RESULTS

Copper increased intracellular ROS, resulted in morphological abnormalities, nuclear condensation, and disrupted MMP. Moreover, Cu caused apoptotic cell deaths characterized by overexpressed pro-apoptotic proteins such as poly (ADP-ribose) polymerase (PARP), cysteine-dependent aspartate-specific proteases 3 (Caspase 3), and Bcl-2-associated X protein (Bax) and downregulated anti-apoptotic proteins such as B-cell lymphoma 2 (Bcl-2), respectively. However, quercetin restored overexpressed pro-apoptotic proteins and induced autophagosome-bound microtubule-associated protein light chain-3 (LC3II) conversion from LC3I. Furthermore, Cu-modulated autophagy marker proteins, including sequestosome-1 (p62), heat shock cognate proteins (Hsc 70, Hsc 90), lysosome-associated membrane protein (LAMP-2A), and AMP-associated protein kinase (AMPK).

CONCLUSION

This study promotes the nutraceutical ability of quercetin to combat Cu-induced hepatotoxicity by understanding the intricate biological signaling pathways within cells.

Discolored urine in sheep and goats: Clinical, etiological, hematobiochemical, sonographic and postmortem findings

Background

Bloody urine is classified in farm animals as hematuria, hemoglobinuria, and myoglobinuria. In small ruminants, discolored urine is reported due to several etiologies which is sometimes fatal. Of these causes are babesiosis, bacillary hemoglobinuria, copper toxicity, and hypophosphatemia.

Aim

This study was designed to investigate the clinical, etiological, hematobiochemical, ultrasonographic, and pathological findings in rams and bucks with red urine syndrome.

Methods

Eighteen male animals (nine rams and nine bucks) of 6 months to 3 years were examined. Parallel, 10 healthy controls were used. They were admitted due to red urine, voiding of only urine drops, straining during the act of urination, grunting during urination, ventral abdominal edema, and abdominal distension. The duration of the disease ranged from 2 to 30 days. A history of chronic copper toxicosis was informed in two bucks and a ram. Two blood samples were collected from diseased as well as from controls in EDTA tubes (for complete blood count testing) and in plain tubes (for serum collection).

Results

Hematuria was found in 11 animals (seven bucks and four rams) while hemoglobinuria was detected in seven animals (five bucks and two rams). Sonographic findings in diseased animals included ruptured urinary bladder in 3, ruptured urethra in 5, penile calculi, uroperitoneum in 6, distended urinary bladder in 7, hydronephrosis in 5, echogenic deposits in the bladder in 3, and ventral urine accumulation in four animals. Laboratory evaluation of a Geimsa-stained blood smear confirmed the infection with Babesia in three bucks and a ram. Hemolytic anemia was marked in two bucks and a ram due to chronic copper toxicity. Biochemical abnormalities included hypoalbuminemia, hyperglobulinemia, increased blood urea nitrogen and creatinine concentration, and hyperglycemia. Postmortem examination was carried out on six animals (four rams and two bucks).

Conclusion

Discolored urine in rams and bucks in this study resulted from hematuria due to urinary calculi and pelvic abscessation or from hemoglobinuria due to Babesia infection or due to copper toxicity. Hemolytic anemia was the outstanding hematological finding and hypoalbuminemia, hyperglobulinemia, increased blood urea nitrogen (BUN) and creatinine, and hyperglycemia were the characteristic biochemical findings. Sonography of the urinary tract was very helpful in assessing the renal parenchyma, urinary bladder, and abdominal cavity for the verification of urolithiasis, hydronephrosis, intact or ruptured urinary bladder, uroperitoneum, and perforated urethra.

Copper Intoxication in South American Camelids-Review of the Literature and First Report of a Case in a Vicuña (Vicugna vicugna)

Copper (Cu), an essential trace element in the metabolism of mammals, plays a central role in various metabolic processes. However, overdosing can lead to severe symptoms and even fatalities. Chronic Cu intoxication continues to be a problem in grazing and domestic animals, with sheep being particularly sensitive. There are few comparative studies on its impact on South American camelids (SACs). Therefore, this work presents the results of literature research combined with a case report on a 3-year-old female vicuña (Vicugna vicugna) presented to the clinic from a zoological garden in northern Germany. The animal showed reduced food intake, recumbency, bruxism, icteric mucous membranes and sclera. Auscultation revealed atony of the third compartment and the digestive tract. Similar to cases described in the literature, the animal showed rapid deterioration of its condition with unspecific symptoms of liver failure and rapid death. However, in contrast to descriptions in sheep, clinical icterus has not been previously reported in cases of other SACs. Laboratory findings from EDTA and serum samples revealed neutrophilia with a left shift, hypoproteinaemia, lymphopaenia, azotaemia, elevated levels of creatine kinase (CK), aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH) in the serum. Hyperbilirubinaemia and significantly elevated serum and liver Cu levels were observed. Subsequent blood samples from the remaining vicuñas and alpacas in the same enclosure showed no remarkable abnormalities. To the best of the authors' knowledge, this case report represents the first documented case of Cu intoxication specifically in vicuñas.

Accumulation of copper and lead in ruminants grazing on a contaminated shooting range in Nordland County, Norway

Shooting ranges contain copper (Cu) and lead (Pb) contamination, which can be a risk for grazing ruminants. This study examines the accumulation of lead and copper in blood of lambs and calves, as well as in the liver of lambs. It compares these results with those of a previous study, which calculated the ingested dose of copper and lead based on soil ingestion and concentration in soil and plants. Blood samples were collected both before and after the grazing period that lasted from late May to mid-September. Liver samples were obtained during the slaughter of the lambs in the fall. Out of 61 liver samples, only one (3.7 mg Pb/kg dw) exceeding the presumed normal level in lamb liver of 3 mg/kg (dw). Copper concentrations exceeding the normal (300 mg/kg dw) concentration was found in 14 of the liver samples (341-1877 mg Cu/kg dw). Among these, two liver samples (1069 and 1877 mg Cu/kg dw) exceeded the level at which sheep are poisoned (1000 mg/kg dw). There was no statistically significant difference in the copper and lead concentration in liver of lambs that did and did not have the shooting range as part of their pasture. The average concentration of copper (lamb: 1.1 ± 0.37 µg Cu/g, calves: 0.6 ± 0.16 µg Cu/g) and lead (lamb: 0.010 ± 0.008 µg Pb/g calves: 0.01 ± 0.014 µg Pb/g) in the blood samples collected from the lambs and calves did not exceed the upper limit of what is considered normal (sheep: 1.35 mg Cu/kg and 0.3 mg Pb/kg, cattle: 1.7 mg Cu/kg and 0.35 mg Pb/kg). Copper concentration in the blood was notably higher in samples collected from the sheep before (1.3 ± 0.35 µg Cu/g) compared to after (0.8 ± 0.22 µg Cu/g) the grazing period. No statistically significant difference was found in lead and copper concentrations in the blood of lambs and calves grazing inside (lamb: 0.7 ± 0.21 µg Cu/g and 0.01 ± 0.008 µg Pb/g, calves: 0.6 ± 0.16 µg Cu/g and 0.02 ± 0.020 µg Pb/g) and outside (lamb: 0.9 ± 0.21 µg Cu/g and 0.13 ± 0.008 µg Pb/g, calves: 0.6 ± 0.17 µg Cu/g and 0.009 µg Pb/g) the shooting range. Grazing on areas contaminated by shooting activity did not appear to have any major implications for the accumulation of copper and lead in blood of cattle and sheep, as well as in the liver of sheep. The findings from this study indicate that employing site specific risk assessments for ruminants incorporating soil ingestion represents a viable approach.

Cuproptosis: emerging biomarkers and potential therapeutics in cancers

The sustenance of human life activities depends on copper, which also serves as a crucial factor for vital enzymes. Under typical circumstances, active homeostatic mechanisms keep the intracellular copper ion concentration low. Excess copper ions cause excessive cellular respiration, which causes cytotoxicity and cell death as levels steadily rise above a threshold. It is a novel cell death that depends on mitochondrial respiration, copper ions, and regulation. Cuproptosis is now understood to play a role in several pathogenic processes, including inflammation, oxidative stress, and apoptosis. Copper death is a type of regulatory cell death(RCD).Numerous diseases are correlated with the development of copper homeostasis imbalances. One of the most popular areas of study in the field of cancer is cuproptosis. It has been discovered that cancer angiogenesis, proliferation, growth, and metastasis are all correlated with accumulation of copper ions. Copper ion concentrations can serve as a crucial marker for cancer development. In order to serve as a reference for clinical research on the product, diagnosis, and treatment of cancer, this paper covers the function of copper ion homeostasis imbalance in malignant cancers and related molecular pathways.

A review of important heavy metals toxicity with special emphasis on nephrotoxicity and its management in cattle

Toxicity with heavy metals has proven to be a significant hazard with several health problems linked to it. Heavy metals bioaccumulate in living organisms, pollute the food chain, and possibly threaten the health of animals. Many industries, fertilizers, traffic, automobile, paint, groundwater, and animal feed are sources of contamination of heavy metals. Few metals, such as aluminum (Al), may be eliminated by the elimination processes, but other metals like lead (Pb), arsenic (As), and cadmium (Ca) accumulate in the body and food chain, leading to chronic toxicity in animals. Even if these metals have no biological purpose, their toxic effects are still present in some form that is damaging to the animal body and its appropriate functioning. Cadmium (Cd) and Pb have negative impacts on a number of physiological and biochemical processes when exposed to sub-lethal doses. The nephrotoxic effects of Pb, As, and Cd are well known, and high amounts of naturally occurring environmental metals as well as occupational populations with high exposures have an adverse relationship between kidney damage and toxic metal exposure. Metal toxicity is determined by the absorbed dosage, the route of exposure, and the duration of exposure, whether acute or chronic. This can lead to numerous disorders and can also result in excessive damage due to oxidative stress generated by free radical production. Heavy metals concentration can be decreased through various procedures including bioremediation, pyrolysis, phytoremediation, rhizofiltration, biochar, and thermal process. This review discusses few heavy metals, their toxicity mechanisms, and their health impacts on cattle with special emphasis on the kidneys.