Investigation of the Protective Role of Selenium in the Changes Caused by Chlorpyrifos in Trace Elements, Biochemical and Hematological Parameters in Rats

Selenium Treatment Alleviates the Inhibition Caused by Nep-L Gene Knockdown in Silkworm (Bombyx mori)

Recent studies have emphasized the beneficial effects of 50 μM selenium (Se) on the growth and development of the silkworm, Bombyx mori; however, less is known about its underlying mechanism. To unravel the effect of 50 μM Se on the silkworms with neutral endopeptidase 24.11-like gene (NEP-L) knockdown, we injected small interfering RNA (siRNA) into the body cavity of silkworms. Phenotypic characteristics, mRNA expression of the Nep-L gene, and enriched Se content were evaluated in silkworms from each treatment group. After injecting Nep-L siRNA, the body weight, cocoon quality (cocoon weight, cocoon shell weight, and cocoon shell ratio), and egg production of silkworms were significantly reduced, without any significant effect on egg laying number. However, Se treatment could significantly alleviate the inhibition of body weight, and cocoon quality, without significant effects on egg laying number and production. In addition, the gene knockdown increased Se content in the B. mori. On the molecular level, the targeted Nep-L gene was inhibited significantly by siRNA interference, essentially with the strongest effect at 24 h after RNAi, followed by steady recovery. Among the three fragments, the siRNA of Nep-L-3 was the most effective in interfering with target gene expression. Nep-L gene showed the highest expression in Malpighian tubules (MTs). Both at the phenotypic and genotypic levels, our results show that Nep-L knockdown can exert a significant inhibitory effect on silkworms, and 50 μM Se can reverse the negative effect, which provides a practical prospect for strengthening the silkworm food industry.

Study on Soil Selenium-Induced Copper Deficiency in Yudong Black Goats

Due to the degradation of pasture and strict restrictions on grazing ranges in recent years, copper (Cu) deficiency in Yudong black goats has been occurring, mainly manifested as emaciation, anemia, loss of appetite and lack of spirit. To explore the main causes of Cu deficiency in Yudong black goats, 40 black goats (1 year old, 25.11 ± 0.52 kg) were selected for this experiment; among them, 20 Yudong black goats with Cu deficiency from the experimental pasture were used as the experimental group, and 20 healthy Yudong black goats from the control pasture were used as the control group. In the pre-experiment, the mineral contents of the soil, forage, blood, and liver of black goats in both groups were determined, and in formal experiments, blood hematological, biochemical, antioxidant, and hemorheological parameters were analyzed. An experiment on the treatment of Cu deficiency in black goats was also conducted. This study showed that selenium (Se) levels in the soil, forage, blood, and liver from the experimental group were significantly lower than those from the control group (p < 0.01). The content of sulfur (S) in the forage was considerably higher than that of the control group (p < 0.01). The contents of Cu in the blood and liver from the experimental group were significantly lower than that from the control group (p < 0.01), and the content of S was considerably higher than that from the control group (p < 0.01). The blood hematology of the experimental group was affected, as evidenced by a decrease in hemoglobin, hematocrit value, mean corpuscular volume and mean corpuscular hemoglobin. The immunity and antioxidant capacity of black goats in the experiment group were impaired to varying degrees, with significant decreases in ceruloplasmin, immunoglobulin M, immunoglobulin G, glutathione peroxidase, and superoxide dismutase, and substantial increases in malondialdehyde. In addition, the experimental group showed a decrease in blood viscosity as evidenced by the rise in high shear viscosity, low shear viscosity, erythrocyte rigidity index, erythrocyte aggregation index, and erythrocyte deformation index, and a decrease in plasma viscosity. In the treatment experiment, oral administration of copper sulfate solution was carried out on 10 black goats with Cu deficiency. All the Cu deficiency goats were cured, and the Cu content in their bodies rebounded. In summary, low Se soil caused an increase in S content in the forage, and Yudong black goats feeding on high S forage resulted in a decrease in Cu absorption, which led to a secondary Cu deficiency.

Abnormal Phenylalanine Metabolism of Procapra przewalskii in Chronic Selenosis in Selenium-Enriched Habitats

Selenium (Se)-enriched habitats have led to chronic selenosis, seriously affecting the health and survival of Procapra przewalskii (P. przewalskii). Our targets were to explore the molecular mechanisms of chronic selenosis and to look for a new way to protect endangered species. The mineral contents of soils, grass, blood, and muscle were analyzed. The biochemical indices, antioxidant capability, and immune function were also investigated. The analyses of proteomics and metabolomics were also carried out. The results showed that the Se contents in the muscle and blood of P. przewalskii, and the soil and grass in the Se-enriched habitats were significantly higher than those in healthy pastures. The P. przewalskii in the Se-enriched habitats showed symptoms of anemia, decreased antioxidant capability, and low immune function. A total of 44 differential proteins and 36 differential metabolites were screened by analyzing their proteomics and metabolomics. These differential proteins and metabolites were involved in glycolysis pathway, amino acid biosynthesis, carbon metabolism, phenylalanine metabolism, and energy metabolism. In particular, phenylalanine metabolism was the common pathway of proteomics and metabolomics, which was an important finding in studying the mechanism of chronic selenosis in animals. This study will help us to further understand the mechanism of chronic selenosis in P. przewalskii, and it provides a scientific basis for the protection of endangered species in Se-enriched habitats.

Comparative Effect of the Active Substance of Thyme with N-Acetyl Cysteine on Hematological Parameters and Histopathological Changes of Bone Marrow and Liver in Rat Models of Acetaminophen Toxicity

Acetaminophen has always been at the center of attention as a non-steroidal anti-inflammatory drug, which is generally associated with the serious side effects on liver and the hematological parameters. This study aimed to compare the effect of N-acetyl cysteine (NAC) and thyme extract on rat models of acetaminophen-induced toxicity. The present experimental study was conducted on 48 Wistar rats randomized into six groups, including the control group (no treatment); the Ac group (470 mg/kg of acetaminophen); the Ac + 100Ex, Ac + 200Ex, and Ac + 400Ex groups (acetaminophen + thyme extract at doses of 100, 200, 400 mg/kg); and Ac + NA group (acetaminophen + NAC). After weighing, a blood sample was taken from heart at the end of the period. The measured parameters were hematological, liver biochemical, and oxidative stress profiles. A part of the liver tissue was also fixed for the pathological examinations. The bone marrow was aspirated to check for cellular changes as well. The lowest mean of the final weight and liver weight to body weight ratio was observed in the Ac group. Weight loss was compensated in Ac + NA and Ac + 200Ex groups (P = 0.035). White blood cell (WBC), red blood cell (RBC), Hemoglobin (Hgb), and Hematocrit (HCT) in Ac and Ac + 400Ex groups showed significant differences from those of the other test groups (P < 0.001). Aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) enzymes in Ac + 200Ex and Ac + NA groups showed a significant decrease compared to those of the other treatment groups (P = 0.043). Total antioxidant capacity (TAC) and glutathione peroxidase (GPx) had the lowest levels in Ac and Ac + 400Ex groups, while malondialdehyde (MDA) had the highest content. In this regard, the liver histopathological indices (necrosis, hyperemia, and hemorrhage) in the Ac + 200Ex and Ac + NA groups reached their lowest grades in the treatment groups. The mean number of erythroid and myeloid cells in the Ac group reached the lowest (17.40 ± 3.48). The microscopic appearance of the bone marrow cells was different from normocytosis in the control group to hypocytosis in the Ac and Ac + 400Ex groups. Thymol, as an effective ingredient in thyme extract at a dose of 200 mg/kg compared to NAC, had a unique effect on reducing bone marrow and liver cell-tissue changes due to the acetaminophen toxicity.

Selenium Heals the Chlorpyrifos-Induced Oxidative Damage and Antioxidant Enzyme Levels in the Rat Tissues

Chlorpyrifos (CPF), mainly exposed by oral, dermal, or inhalation, is a broad-spectrum organophosphate pesticide used in pest control, increasing agricultural productivity, and being considered toxic to living things. Selenium (Se), an essential component of selenoenzymes and selenoproteins, is an essential element that protects cells from oxidative stress and has antioxidant properties. The study aimed to examine the oxidative stress caused by different doses of CPF exposure in brain, liver, and kidney tissues while observing the healing effect of Se application on tissue damage and antioxidant levels. A total of 56 rats were divided into seven different groups: 1st group control (water); 2nd group sham (corn oil); the 3rd group was CPF-L (5.4 mg/kg CPF); the 4th group was CPF-H (13.5 mg/kg CPF); the 5th group was Se (3 mg/kg Se); 6th group was CPF-L + Se (5.4 mg/kg CPF + 3 mg/kg Se); the 7th group was CPF-H + Se (13.5 mg/kg CPF + 3 mg/kg Se). The brain, liver, and kidney tissues were obtained from rats sacrificed 6 weeks later. Acetylcholinesterase (AChE), oxidant, and antioxidant parameters were examined in the tissues. The results suggest that CPF causes neurotoxicity, hepatotoxicity, and renal toxicity by altering AChE levels, inducing lipid peroxidation, and decreasing antioxidant systems. Se treatment increased the activities of AChE and, antioxidant defense system and reduced the malondialdehyde (MDA) levels in the brain, liver, and kidney tissues of rats. Se was found to heal and also protect these tissues against these changes resulting from CPF exposure.

Chitosan oligosaccharide alleviates and removes the toxicological effects of organophosphorus pesticide chlorpyrifos residues

The abuse of chlorpyrifos (CHP), a commonly used organophosphorus pesticide, has caused many environmental pollution problems, especially its toxicological effects on non-target organisms. First, CHP enriched on the surface of plants enters ecosystem circulation along the food chain. Second, direct inflow of CHP into the water environment under the action of rainwater runoff inevitably causes toxicity to non-target organisms. Therefore, we used rats as a model to establish a CHP exposure toxicity model and studied the effects of CHP in rats. In addition, to alleviate and remove the injuries caused by residual chlorpyrifos in vivo, we explored the alleviation effect of chitosan oligosaccharide (COS) on CHP toxicity in rats by exploiting its high water solubility and natural biological activity. The results showed that CHP can induce the toxicological effects of intestinal antioxidant changes, inflammation, apoptosis, intestinal barrier damage, and metabolic dysfunction in rats, and COS has excellent removal and mitigation effects on the toxic damage caused by residual CHP in the environment. In summary, COS showed significant biological effects in removing and mitigating blood biochemistry, antioxidants, inflammation, apoptosis, gut barrier structure, and metabolic function changes induced by residual CHP in the environment.

3-Indolepropionic acid prevented chlorpyrifos-induced hepatorenal toxicities in rats by improving anti-inflammatory, antioxidant, and pro-apoptotic responses and abating DNA damage

The application of chlorpyrifos (CPF), an organophosphorus pesticide to control insects, is associated with oxidative stress and reduced quality of life in humans and animals. Indole-3-propionic acid (IPA) is a by-product of tryptophan metabolism with high antioxidant capacity and has the potential to curb CPF-mediated toxicities in the hepatorenal system of rats. It is against this background that we explored the subacute exposure of CPF and the effect of IPA in the liver and kidney of thirty rats using five cohort experimental designs (n = 6) consisting of control (corn oil 2 mL/kg body weight), CPF alone (5 mg/kg), IPA alone (50 mg/kg), CPF + IPA₁ (5 mg/kg + 25 mg/kg), and CPF + IPA₂ (5 mg/kg + 50 mg/kg). Subsequently, we evaluated biomarkers of hepatorenal damage, oxidative and nitrosative stress, inflammation, DNA damage, and apoptosis by spectrophotometric and enzyme-linked immunosorbent assay methods. Our results showed that co-treatment with IPA decreased CPF-upregulated serum hepatic transaminases, creatinine, and urea; reversed CPF downregulation of SOD, CAT, GPx, GST, GSH, Trx, TRx-R, and TSH; and abated CPF upregulation of XO, MPO, RONS, and LPO. Co-treatment with IPA decreased CPF-upregulated IL-1β and 8-OHdG levels, caspase-9 and caspase-3 activities, and increased IL-10. In addition, IPA averts CPF-induced histological changes in the liver and kidney of rats. Our results demonstrate that co-dosing CPF-exposed rats with IPA can significantly decrease CPF-induced oxidative stress, pro-inflammatory responses, DNA damage, and subsequent pro-apoptotic responses in rats' liver and kidneys. Therefore, supplementing tryptophan-derived endogenous IPA from exogenous sources may help avert toxicity occasioned by inadvertent exposure to harmful chemicals, including CPF-induced systemic perturbation of liver and kidney function.

Effects of Selenium in Different Valences on the Community Structure and Microbial Functions of Biofilms

With the wide application of selenium (Se) in industrial production, different Se-based compounds (selenate and selenite) are produced and released into aquatic environments. The potential impacts of such Se compounds on the biofilms (a complex microbial aggregate in aquatic systems) need to be substantially explored. Herein, we investigated the responses of bacterial community diversity, composition and structure, and function of biofilms after 21 days of exposure to low concentrations (100 µg/L) and high concentrations (1 mg/L) of sodium selenate and sodium selenite, respectively. Distinct effects of selenium in different valences on the community structure and microbial functions of biofilms were observed. Compared with the controls, the addition of selenate and selenite solutions altered the richness of biofilms but not the diversity, which is dependent on the concentration and valences, with sodium selenite (1 mg/L) exhibiting a strong inhibition effect on community richness. Significant changes of community composition and structure were observed, with a significant increase in Proteobacteria (31.08–58.00%) and a significant decrease in Bacteroidetes (32.15–11.45%) after exposure to sodium selenite with high concentration. Also, different responses of gamma-Proteobacteria and alpha-Proteobacteria were observed between the sodium selenite and sodium selenate treatments. Moreover, results showed that sodium selenite could strengthen the function of the metabolism of biofilms, and the higher the concentration is, the more apparent the enhancement effect is. All these results suggested that the effects of different valence states of selenium were obvious, and sodium selenite with high concentration strongly changed the diversity, structure and function of biofilms.