Effects of Organic Copper on Growth Performance and Oxidative Stress in Mice

Effects of Cu(Ⅱ) stress on embryonic development, oxidative stress response, cholinergic system and energy metabolism in the Sepiella maindroni

In order to investigate the causes of population degradation and resource decline, this thesis investigated the ecotoxicological effects of heavy metal Cu(Ⅱ) on the embryonic development of Sepiella maindroni. Results indicate significant effects of Cu(Ⅱ) concentrations on the developmental toxicity, teratogenicity, and lethality of S. maindroni embryos. Different concentrations of Cu(Ⅱ) caused varying degrees of malformations in embryos, altered developmental rates, reduced hatchability and hatchling quality, and increased malformation and mortality of hatchlings. At the same time, Cu(Ⅱ) exposure led to an increase in the content of the lipid peroxidation product malondialdehyde (MDA) and a significant decrease in the activity of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT]), energy-metabolizing enzymes (adenylate kinase [AK]), and cholinergic-related enzymes (acetylcholinesterase [AChE], choline acetyltransferase [ChAT]). In conclusion, when the concentration of Cu(Ⅱ) in the environment is ≥ 0.01 mg/L, it causes significant lethality toxicity, developmental toxicity and teratogenicity in S. maindroni embryos. These effects are likely related to Cu(Ⅱ)-induced stress impacting the antioxidant capacity, energy metabolism, and cholinergic system. Ultimately, these toxic effects may lead to population degradation and resource decline in fishery organisms by affecting the early replenishment process of fisheries.

Pseudomonas aeruginosa Y12 play positive roles regulating larval gut communities when housefly encountered copper stress

Heavy metal contamination has become a global concern that threatens the lives of animals and insects throughout the food chain. Pseudomonas is a commonly found genus of bacteria that colonizes the intestines of insects and constitutes a necessary part of the insect gut microbiota. This research analyzed the influence of different concentrations of Cu²⁺ on housefly larval development, gut microbial structure and antioxidant defense system, and investigated the regulatory mechanism of P. aeruginosa Y12 on the gut microbiota when houseflies were exposed to Cu²⁺. We found that adding Cu²⁺ to the larval diet inhibited larval growth, while the mixed addition of P. aeruginosa Y12 and Cu²⁺ to the diet reduced the inhibitory effects of Cu²⁺ on larval growth. Oral administration of Cu²⁺ significantly changed the gut community structure and increased larval gut bacterial diversity. In vitro analysis revealed that P. aeruginosa Y12 showed Cu²⁺ adsorption effects and increased Cu²⁺ aggregation. The mixed addition of low concentrations of P. aeruginosa Y12 and Cu²⁺ to the larval diet caused a dynamic shift in the gut microbiota and resulted in a novel gut community structure with an increase in beneficial bacteria and a decrease in pathogenic bacteria. Furthermore, P. aeruginosa Y12 treatment influenced the activity of antioxidant enzymes in housefly larvae, indicating that the addition of P. aeruginosa Y12 to the larval diet could further influence the antioxidant system through P. aeruginosa Y12-Cu²⁺ interactions. In conclusion, our research revealed that intestinal flora dysbiosis was the essential reason why copper inhibits housefly larval growth. However, proper supplementation with P. aeruginosa Y12 played positive roles in regulating larval gut communities and protecting insects from toxic heavy metals.

Latent Benefits and Toxicity Risks Transmission Chain of High Dietary Copper along the Livestock-Environment-Plant-Human Health Axis and Microbial Homeostasis: A Review

The extensive use of high-concentration copper (Cu) in feed additives, fertilizers, pesticides, and nanoparticles (NPs) inevitably causes significant pollution in the ecological environment. This type of chain pollution begins with animal husbandry: first, Cu accumulation in animals poisons them; second, high Cu enters the soil and water sources with the feces and urine to cause toxicity, which may further lead to crop and plant pollution; third, this process ultimately endangers human health through consumption of livestock products, aquatic foods, plants, and even drinking water. High Cu potentially alters the antibiotic resistance of soil and water sources and further aggravates human disease risks. Thus, it is necessary to formulate reasonable Cu emission regulations because the benefits of Cu for livestock and plants cannot be ignored. The present review evaluates the potential hazards and benefits of high Cu in livestock, the environment, the plant industry, and human health. We also discuss aspects related to bacterial and fungal resistance and homeostasis and perspectives on the application of Cu-NPs and microbial high-Cu removal technology to reduce the spread of toxicity risks to humans.

The influence of gastrointestinal pH on speciation of copper in simulated digestive juice

Speciation can provide knowledge about absorption, reactivity to binding sites, bioavailability, toxicity, and excretion of elements. In this study, the speciation of copper in different model solutions under the influence of gastrointestinal (GI) pH was studied by ion selective electrode (ISE) and inductively coupled plasma optical emission spectrometry (ICP OES). It was found that the electrode response (mV) against Cu2+ decreased with the increase in pH and dropped to the lowest point at pH 7.5 in all model solutions. When amino acids and organic acids were present, the ratio of filtered copper (0.45 μm, pH 7.5) was more than 90%. When casein was present, whey protein, pancreatin, and starch were added, and the ratio of filtered copper was 85.6 ± 0.3, 56.7 ± 8.8, 38.5 ± 5.1, and 1.0 ± 0.3%, respectively. When there is not enough organic ligand, excessive copper will form copper hydroxide precipitation with the increase in pH, but it got the highest electrode response (mV) against Cu2+. From this study, it can be concluded that the speciation of copper in GI tract is strongly influenced by the pH and the composition of food. When there are few ligands coexisting in the GI tract, the concentration of copper ion may be relatively high.

Biosorption of Copper in Swine Manure Using Aspergillus and Yeast: Characterization and Its Microbial Diversity Study

Dietary copper supplementation in the feed of piglets generally exceeds 250-800 mg/kg, where a higher quantity (>250 mg/kg) can promote growth and improve feed conversion. Despite the reported positive effects, 90% of copper is excreted and can accumulate and pollute the soil. Data indicate that fungi have a biosorptive capacity for copper. Thus, the objectives of the present experiment were to study the effects of adding different strains of fungi on the biosorptive capacity for copper in swine manure and to evaluate potential effects on microbiota profiles. Aspergillus niger (AN), Aspergillus oryzae (AO), and Saccharomyces cerevisiae (SC) were selected, and each added 0.4% into swine manure, which contain 250 mg/kg of copper. The incubations lasted for 29 days, and biosorption parameters were analyzed on the 8th (D8), 15th (D15), 22nd (D22), and 29th (D29) day. Results showed that after biosorption, temperature was 18.47-18.77°C; pH was 6.33-6.91; and content of aflatoxin B1, ochratoxin A, and deoxynivalenol were low. In addition, residual copper concentration with AN was the lowest on D15, D22, and D29. The copper biosorption rate was also highest with AN, averaging 84.85% on D29. Biosorption values for AO reached 81.12% and for SC were lower than 80%. Illumina sequencing of 16S and ITS rRNA gene revealed that fungal treatments reduced the diversity and richness of fungal abundance, but had no effect on bacterial abundance. Unknown_Marinilabiliaceae, Proteiniphilum, Tissierella, and Curvibacter were the dominant bacteria, while Aspergillus and Trichoderma were the dominant fungi. However, the added strain of S. cerevisiae was observed to be lower than the dominant fungi, which contained less than 0.05%. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment predicted via PICRUSt2 that there were bacterial genes potentially related to various aspects of metabolism and environmental information processing. Overall, data indicated that Aspergillus can provide microbial materials for adsorption of copper.

Chronic tribasic copper chloride exposure induces rat liver damage by disrupting the mitophagy and apoptosis pathways

Despite the fact that copper (Cu) is a vital micronutrient to maintain body function, high doses of Cu through environmental exposure damage various organs, especially the liver, which is the main metabolic organ. To investigate the influence of long-term Cu-induced toxicity on mitophagy and apoptosis in rat liver, 96 seven-month-old male Sprague-Dawley rats were fed TBCC for 24 weeks. The results revealed that exposure to high Cu concentrations could promote oxidative stress liver injury by increasing the hepatic function index (ALT, AST and ALP) and MDA content, while reducing the activity of antioxidant enzymes (T-SOD, GSH-Px and CAT) related to oxidative stress. Consistent with histopathological observations, proper dietary Cu (15-60 mg/kg) could improve antioxidant stress levels and induce a dose-dependent increase in the mRNA expression of mitophagy-related genes, whereas a high Cu concentration (120 mg/kg) could cause severe liver impairment and ultrastructural changes and a reduction in mitophagosomes, accompanied by downregulation of Atg5, Beclin1, Pink1, Parkin, NIX, P62 and LC3B. The expression of apoptosis-related genes (Bax, Bax/Bcl-2, Caspase3, Cytc and p53) and proteins (Caspase3 and p53) was upregulated with the addition of dietary Cu. The results demonstrated that an appropriate dose of TBCC could improve liver function by promoting mitophagy and Cu enzymes that play antioxidative roles, while the accumulation of excess Cu could induce liver lesions by enhancing apoptosis and inhibiting mitophagy pathways.