Antioxidant effects of N-acetylcysteine and succimer in red blood cells from lead-exposed rats

Temporal and spatial trends in lead levels in the blood and down of Black Stork nestlings in central Europe

Young birds at an intensive growth stage are especially vulnerable to the deleterious effects of contaminants such as lead (Pb). This element negatively influences organs, development and even behavior, which can consequently lead to lower survival and reproductive success of the population. There was a suspicion that these mechanisms, along with other factors, retarded population growth of the Black Stork - still a heavily understudied species in respect to pollution, especially Pb. Therefore, we undertook a study concerning Pb concentrations in the down and blood of Black Stork nestlings from breeding grounds in central and southern Poland (Europe). To investigate the effects of Pb exposure on nestling condition, scale mass index and reduced glutathione levels were also studied, but results indicated that Pb did not influence either of these parameters. The highest blood Pb concentration reached 0.247 μg/g, while the highest down Pb concentrations was significantly higher reaching 4.95 μg/g. Concentrations in blood and down were not correlated with each other. Nest location and year of sampling were not influential for blood but were influential for down Pb concentrations. Relationships between Pb concentrations, habitat characteristics and proximity to emitters were not significant. Overall Pb concentrations in Black Stork nestlings were below the toxicity threshold and did not have negative effects on specimens studied. They were probably related to maternal exposure during migration, on stopover and breeding grounds as well as with food provided by parents.

Aronia melanocarpa Flavonol Extract-Antiradical and Immunomodulating Activities Analysis

The study of Aronia melanocarpa's (A. melanocarpa) biological activity is focused on obtaining the crude extract and separation of the flavonol compounds. The extraction and fractionation of A. melanocarpa fruits, followed by quantitative analysis, were accomplished using high-performance liquid chromatography and Darco G-60 filtering. This approach enabled the quantification of flavonoids within each fraction. The antioxidative, immunomodulating activities and cytotoxicity with respect to the lymphoblast cell line RPMI-1788 were studied. The flavonol extract of A. melanocarpa has been shown to have a high capacity to neutralize free DPPH and AAPH radicals in vitro. It also caused an accelerated 'respiratory burst' formation of neutrophils and an increase in the metabolic reserves of cells in rats exposed to cyclophosphamide. The reference solution (an equivalent quercetin-rutin blend) contributed to a decrease in lipid peroxidation, intensifying phagocytosis processes. The studied compounds demonstrated their low influence on the leukocyte blood profile in animals.

Curcumin and cinnamon mitigates lead acetate-induced oxidative damage in the spleen of rats

Lead toxicity is a common occupational and environmental health hazard that exerts many toxic effects on animals and humans, including immunotoxicity. Curcumin (CUR) and cinnamon (CIN) are common medicinal herbs with immunostimulatory and antioxidant properties. Therefore, this study investigated the protective effect of curcumin and cinnamon against lead acetate (LA)-induced splenotoxicity in rats via hemato-biochemical, immunological, oxidative stress marker, CYP-2E1 expression, histological, and immunohistological evaluations. Four groups of seven rats each were used: the control group received corn oil as a vehicle; the lead acetate group received (100 mg/kg), the CUR + LA group received curcumin (400 mg/kg) plus lead acetate, and the CIN + LA group received cinnamon (200 mg/kg) plus lead acetate orally for 1 month. LA exposure induced macrocytic hypochromic anemia, leukocytosis, neutrophilia, monocytosis, and lymphopenia. Additionally, significant elevations in serum iron, ferritin levels, and transferrin saturation percentage with significant decline of total and unsaturated iron binding capacities (TIBC and UIBC), transferrin, and immunoglobulin G and M levels were recorded. In addition, lead acetate significantly upregulated splenic CYP-2E1 expression, that was evident by significant depletion of reduced glutathione (GSH) activity and elevation of malondihyde (MDA), nitric oxide (NO), and protein carbonyl (PC) concentrations in the spleen. Histologically, hyperplasia of lymphoid follicles, hemosiderin deposition, and disturbance of CD3 and CD68 immuno-expressions were evident in the spleen from the lead acetate group. However, curcumin and cinnamon administration restored the hemato-biochemical, immunological, and oxidative stress parameters as well as histological and immunohistological pictures toward normalcy. In conclusion, curcumin and cinnamon can partially ameliorate LA-induced oxidative damage in the spleen, possibly through their antioxidant, immunomodulatory, and gene-regulating activities.

Effects of Long-Term Lead Exposure on Antioxidant Enzyme Defense System in Organs of Brown Hare (Lepus europaeus Pallas) as a Bioindicator of Environmental Pollution in Croatia

In Croatia, Podravina is a well-known lead-polluted region due to the intensive exploitation of natural gas, a highly developed agricultural industry, and a traffic hub with several heavily traveled roads. It represents a natural environment with a great variety of wildlife, especially hares (Lepus europaeus Pallas), which may serve as an indicator for environmental quality assessment. This study was conducted to estimate the bioaccumulation of lead in hare liver, kidney, muscle, and brain during long-term exposure and its impact on the oxidative status of the organism and to investigate a possible lead exchange ionic mechanism in the brain. In the organs of two hare groups (experimental from polluted area and control from the island of Krk), Ca, Fe, Mg, Na, lead concentrations, and antioxidant enzyme defense system were analyzed. The accumulation of lead was highest in the brain (3.7-fold higher compared to the control group) and lowest in the liver (1.6-fold higher compared to the control group). Kendall-Tau and multiple regression analysis showed that the increased lead content caused a stronger exchange of Ca and Na ions in the brain. We proposed that lead either mobilizes intracellular cation stores or causes competitive displacement of Ca from the binding site in intoxicated cells. A linear predictive model for cell intoxication by lead was proposed, where GPx and SOD were predominantly influenced by long-term lead exposure. The presented results showed that long-term lead exposure in hares negatively affected their oxidative status and caused the strongest toxicity in the brain and muscles, making their survival and/or population vulnerable.

Spatial, temporal and environmental differences in concentrations of lead in the blood of Mute swans from summer and winter sites in Poland

Lead (Pb) is a highly toxic pollutant and represents a serious threat to wildlife, affecting various systems in animal bodies. Especially prone to Pb poisoning are waterbirds, which may inadvertently ingest spent gunshot, fishing sinkers and contaminated sediments. This research thus focused on evaluating Pb concentrations in the blood of 170 Mute swans (Cygnus olor; a widespread species of waterbirds) at their summer (urban locations in Małopolskie and rural locations in Świętokrzyskie regions) and winter (the urban section of Wisła River in Krakow) sites in Poland (Europe). The study concentrated on comparing blood Pb concentrations according to sites and locations, verifying the influence of sex and age factors, examining the impact on hematocrit (Ht), glutathione (GSH) levels and body condition. Mean blood Pb concentrations (measured with ICP-OES) differed significantly between summer and winter sites (Regression by Maximum Likelihood Estimation (RML), p < 0.001) reaching higher values at winter sites. Concentrations did not differ from year to year (RML, p = 0.028). At summer sites, concentrations differed from location to location: swans from urban locations in Małopolskie had higher blood Pb concentrations (0.055 μg/g) than from rural Świętokrzyskie (0.008 μg/g; RML, p < 0.001). In summer and winter birds, neither sex nor age groups differed significantly the concentrations (RML, p > 0.231). Pb concentrations correlated weakly with Ht and GSH levels (Spearman test) and had no influence on body condition (proxied by scaled mass index; GLM, p = 0.246). We concluded that differences between summer and winter sites were dictated mainly by the type of habitat (rural vs. urban) that birds occupied in different seasons.

Glycine Betaine Relieves Lead-Induced Hepatic and Renal Toxicity in Albino Rats

Lead (Pb) is a widespread and nondegradable environmental pollutant and affects several organs through oxidative mechanisms. This study was conducted to investigate the antioxidant protective effect of glycine betaine (GB) against Pb-induced renal and hepatic injury. Male albino rats (n = 45) were divided into three groups: G1 untreated control, G2 Pb-acetate (50 mg/kg/day), and G3 Pb-acetate (50 mg/kg/day) plus GB (250 mg/kg/day) administered for 6 weeks. For G3, Pb-acetate was administered first and followed by GB at least 4 h after. Pb-acetate treatment (G2) resulted in a significant decrease in renal function, including elevated creatinine and urea levels by 17.4% and 23.7%, respectively, and nonsignificant changes in serum uric acid levels. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphates (ALP) activities were significantly increased with Pb treatment by 37.6%, 59.3%, and 55.1%, respectively. Lipid peroxidation level was significantly increased by 7.8 times after 6 weeks of Pb-acetate treatment. The level of reduced glutathione (GSH-R) significantly declined after Pb-acetate treatment. Pb-acetate treatment also reduced the activities of superoxide dismutase (SOD), glutathione-S-transferase (GST), and glutathione peroxidase (GSH-PX) by 74.1%, 85.0%, and 40.8%, respectively. Treatment of Pb-intoxicated rats with GB resulted in a significant reduction in creatinine, urea, ALT, AST, and lipid peroxidation, as well as a significant increase in the level of GSH-R and in the activities of ALP, SOD, GST, and GSH-PX. The molecular interaction between GB and GSH-PX indicated that the activation of GSH-PX in Pb-intoxicated rats was not the result of GB binding to the catalytic site of GSH-PX. The affinity of GB to bind to the catalytic site of GSH-PX is lower than that of H₂O₂. Thus, GB significantly mitigates Pb-induced renal and liver injury through the activation of antioxidant enzymes and the prevention of Pb-induced oxidative damage in the kidney and liver.

Possible Treatment Approaches of Sulfur Mustard-Induced Lung Disorders, Experimental and Clinical Evidence, an Updated Review

Sulfur mustard (SM) is one of the major potent chemical warfare that caused the death of victims in World War I and the Iraq-Iran conflict (1980-1988). The respiratory system is the main target of SM exposure and there are no definitive therapeutic modalities for SM-induced lung injury. The effects of the new pharmaceutical drugs on lung injury induced by SM exposure were summarized in this review. Literature review on PubMed, ScienceDirect, and Google Scholar databases was performed to find papers that reported new treatment approach on SM-exposure-induced injury in the respiratory system until October 2019. The search was restricted to sulfur mustard AND induced injury (in vitro studies, animal experiments, and clinical trials) AND respiratory system OR lung, AND treatment in all fields. Two hundred and eighty-three relevant articles were identified that 97 retrieved articles were eligible and were included in the review. Some new pharmaceutical drugs have shown therapeutic potential in controlling various characteristics of lung injury due to SM exposure. Recent studies showed therapeutic effects of mucolytic drugs, non-steroidal drugs, and antibiotics on reducing lung inflammation, oxidative stress responses, and modulating of the immune system as well as improving of respiratory symptoms and pulmonary function tests. Studies on the therapeutic effects of new agents with amelioration or treatment of SM-induced lung injury were reviewed and discussed.

8-Formylophiopogonanone B induces ROS-mediated apoptosis in nasopharyngeal carcinoma CNE-1 cells

Cancer is one of the leading causes of death in the world. It is very important to find drugs with high efficiency, low toxicity, and low side effects for the treatment of cancer. Flavonoids and their derivatives with broad biological functions have been recognized as anti-tumor chemicals. 8-Formylophiopogonanone B (8-FOB), a naturally existed homoisoflavonoids with rarely known biological functions, needs pharmacological evaluation. In order to explore the possible anti-tumor action of 8-FOB, we used six types of tumor cells to evaluate in vitro effects of this agent on cell viability and tested the effects on clone formation ability, scratching wound-healing, and apoptosis. In an attempt to elucidate the mechanism of pharmacological action, we examined 8-FOB-induced intracellular oxidative stress and -disrupted mitochondrial function. Results suggested that 8-FOB could suppress tumor cell viability, inhibit cell migration and invasion, induce apoptosis, and elicit intracellular ROS production. Among these six types of tumor cells, the nasopharyngeal carcinoma CNE-1 cells were the most sensitive cancer cells to 8-FOB treatment. Intracellular ROS production played a pivotal role in the anti-tumor action of 8-FOB. Our present study is the first to document that 8-FOB has anti-tumor activity in vitro and increases intracellular ROS production, which might be responsible for its anti-tumor action. The anti-tumor pharmacological effect of 8-FOB is worthy of further investigation.

Flavonoid fractions of diosmin and hesperidin mitigate lead acetate-induced biochemical, oxidative stress, and histopathological alterations in Wistar rats

This study aims at investigating the protective effects of flavonoid fractions of diosmin and hesperidin in mitigating sub-chronic lead acetate-induced biochemical, oxidative stress, and histopathological alterations in adult male Wistar rats. Forty animals were randomly assigned into five groups, each consisting of eight animals. Group I animals was treated with deionised water only, group II, IV, and V were administered lead acetate 90 mg/Kg body weight (1/20th of the LD50), groups III, and IV was administered Daflon (100 mg/Kg), while group V was administered Daflon (200 mg/Kg), 30 min prior treatment with lead acetate. All treatments lasted for 42 days. Blood lead levels, electrolyte parameters, zinc protoporphyrin (ZPP) levels, activities of antioxidant enzymes, and histopathology of vital organs, were evaluated following standard practice. Sub-chronic lead acetate exposure induced a decrease in levels of serum electrolytes, and activities of antioxidant enzymes, while blood lead levels, ZPP, and malondialdehyde levels were increased. Lead exposure also instigated marked variation in histopathology of vital organs. Conversely, co-treatment with graded doses of daflon improved the levels of blood lead, electrolytes, ZPP, activities of antioxidant enzymes, and histopathology of vital organs. Data obtained from the current study indicate that rats exposed to sub-chronic doses of lead acetate show increased blood lead levels, electrolyte imbalance, alongside impairment in ZPP levels, activities of antioxidant enzymes, and histopathology, while pretreatment using daflon mitigated the ensued perturbations. This, therefore, suggests that consumption of foods enriched with flavonoid fractions of diosmin and hesperidin may be beneficial for individuals inhabiting lead-polluted environments.

Quercetin and Allicin Can Alleviate the Hepatotoxicity of Lead (Pb) through the PI3K Signaling Pathway

Lead (Pb) is a common toxic heavy metal pollutant in the environment that seriously endangers the health of animals. The liver is a key target organ affected by Pb toxicity. Plant extracts allicin and quercetin have a strong antioxidant capacity that can promote the excretion of heavy metals by improving the body's antioxidant defense and chelating heavy metal ions. To explore the preventive and therapeutic effects of allicin and quercetin on Pb poisoning in chickens, 96 chickens were randomly divided into eight groups: control, Pb, allicin, quercetin, allicin + quercetin, Pb + allicin, Pb + quercetin, and Pb + allicin + quercetin groups. The chickens were given feed containing the above treatments for 90 days. The results indicated that Pb can affect the growth and development of the liver, damage the circulatory system, destroy the structure of mitochondria and nuclei in liver cells, cause an imbalance in the oxidation system, inhibit PI3K protein, and activate the mitochondrial apoptotic pathway. Allicin and quercetin, alone or in combination, can improve the antioxidant capacity of the liver and alleviate liver tissue damage caused by Pb. In summary, allicin and quercetin could alleviate oxidative damage and apoptosis in the Pb-poisoned chicken liver through the PI3K signaling pathway, with stronger effects achieved by their combination.

Protective Effects of Chrysin Against Oxidative Stress and Inflammation Induced by Lead Acetate in Rat Kidneys: a Biochemical and Histopathological Approach

In this study, the protective effects of chrysin (CR) on lead acetate (PbAc)-induced renal toxicity in Sprague-Dawley rats were investigated with biochemical, histopathological, and immunohistochemical methods. In the study, rats were given orally at 30 mg/kg/body weight (BW) PbAc after CR of 25 and 50 mg/kg/BW was administered to them orally (a total of 7 administrations for 7 days). The results showed that CR reduced urea and creatinine levels by alleviating PbAc-induced kidney damage. It was determined that CR decreases PbAc-induced lipid peroxidation due to its antioxidant properties and increases catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, and glutathione (GSH) levels. It was also detected that CR protects DNA from the toxic effects of PbAc and reduces 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. Biochemical and immunohistochemical findings demonstrated that CR had anti-inflammatory and antiapoptotic effects and reduced nuclear factor kappa-B (NF-κB), interleukin-33 (IL-33), prostaglandin-E2 (PGE-2), tumor necrosis factor-α (TNF-α), p53 levels, and the activities of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), which were increased with PbAc administration. Moreover, CR was found to increase the levels of aquaporin-1 (AQP-1) and nephrine in PbAc-induced kidney tissue. CR decreased the contents of lead (Pb), zinc (Zn), iron (Fe), sodium (Na), and copper (Cu) and increased those of potassium (K) calcium (Ca) in renal tissue. These results indicated that CR considerably alleviates kidney toxicity caused by PbAc.

MOLECULAR MECHANISMS OF LEAD NEUROTOXICITY

Lead (Pb2+) is a non-essential metal with numerous industrial applications that have led to ts ubiquity in the environment. Thus, not only occupational-exposed individuals' health is compromised, but also that of the general population and in particular children. Notably, although the central nervous system is particularly susceptible to Pb2+, other systems are affected as well. The present study focuses on molecular mechanisms that underlie the effects that arise from the presence of Pb2+ in situ in the brain, and the possible toxic effects that follows. As the brain barriers represent the first target of systemic Pb2+, mechanisms of Pb2+ entry into the brain are discussed, followed by a detailed discussion on neurotoxic mechanisms, with special emphasis on theories of ion mimicry, mitochondrial dysfunction, redox imbalance, and neuroinflammation. Most importantly, the confluence and crosstalk between these events is combined into a cogent mechanism of toxicity, by intertwining recent and old evidences from humans, in vitro cell culture and experimental animals. Finally, pharmacological interventions, including chelators, antioxidants substances, anti-inflammatory drugs, or their combination are reviewed as integrated approaches to ameliorate Pb2+ harmful effects in both developing or adult organisms.

Developmental toxicity of carbon nanoparticles during embryogenesis in chicken

Nanoparticles (NPs) are very small particles present in a wide range of materials. There is a dearth of knowledge regarding their potential secondary effects on the health of living organisms and the environment. Increasing research attention, however, has been directed toward determining the effects on humans exposed to NPs in the environment. Although the majority of studies focus on adult animals or populations, embryos of various species are considered more susceptible to environmental effects and pollutants. Hence, research studies dealing mainly with the impacts of NPs on embryogenesis have emerged recently, as this has become a major concern. Chicken embryos occupy a special place among animal models used in toxicity and developmental investigations and have also contributed significantly to the fields of genetics, virology, immunology, cell biology, and cancer. Their rapid development and easy accessibility for experimental observance and manipulation are just a few of the advantages that have made them the vertebrate model of choice for more than two millennia. The early stages of chicken embryogenesis, which are characterized by rapid embryonic growth, provide a sensitive model for studying the possible toxic effects on organ development, body weight, and oxidative stress. The objective of this review was to evaluate the toxicity of various types of carbon black nanomaterials administered at the beginning of embryogenesis in a chicken embryo model. In addition, the effects of diamond and graphene NPs and carbon nanotubes are reviewed.

Docosahexaenoic Acid (DHA, C22:6, ω-3) Composition of Milk and Mammary Gland Tissues of Lactating Mother Rats Is Severely Affected by Lead (Pb) Exposure

Docosahexaenoic acid (DHA, C22:6, ω-3), an ω-3 polyunsaturated fatty acid (PUFA), is critical for brain growth, development, and cognitive ability. It is consumed by offspring via milk during lactation. However, the toxic heavy metal lead (Pb) readily passes into the mammary glands of mother animals and then to offspring through milk. Here, we investigated whether DHA composition of milk and mammary gland tissues is affected by Pb exposure. Mother rats were exposed to Pb via drinking water (0.1%). The fatty acid profile and levels of reduced glutathione (GSH), lipid peroxide (LPO), and pro-inflammatory TNF-α in milk and mammary tissues were measured. Levels of DHA and antioxidant GSH decreased (P < 0.05), while LPO and TNF-α levels increased (P < 0.05) both in milk and mammary tissues. Our results suggest that toxic Pb exposure can upset the level of milk DHA, which may affect brain growth and development, and hence cognitive ability in adulthood and later life.

A Pilot Study to Evaluate the Effects of Oral N-Acetyl Cysteine on Inflammatory and Oxidative Stress Biomarkers in Rheumatoid Arthritis

BACKGROUND

Rheumatoid Arthritis (RA) is a common inflammatory disease of the joints. Due to the importance of inflammation and oxidative stress in the pathogenesis of RA, drugs that have anti-oxidant and anti-inflammatory properties, such as N-acetyl Cysteine (NAC), can be used as adjunctive therapy in patients with RA.

AIMS

The aim of this study was to evaluate the effects of oral NAC on inflammatory cytokines and oxidative stress in patients with RA.

METHODS

Adjunct to standard treatment, the NAC group (23 patients) received 600 mg of NAC twice daily and the placebo group (19 patients) received identical placebo twice daily for 12 weeks. Serum levels of Total Oxidant Status (TOS), Total Antioxidant Capacity (TAC), nitric oxide (NO), Total Thiol Groups (TTG), Malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), interleukin- 6 (IL-6), C-reactive Protein (CRP), and Erythrocyte Sedimentation Rate (ESR) were measured at baseline and at the end of the study.

RESULTS

Results showed that in the NAC group, the serum levels of MDA, NO, IL-6, TNF-α, ESR and CRP were significantly lower than the baseline. Also, the serum level of TAC and TTG, as antioxidant parameters, increased significantly. However, only NO, MDA and TTG showed a significant difference in the NAC group as compared to the placebo group at the end of study.

CONCLUSION

According to the results of this study, oral NAC can significantly reduce the several oxidative stress factors and inflammatory cytokines. These results need to be confirmed in larger studies while considering clinical outcomes of RA patients.

Medicinal Thiols: Current Status and New Perspectives

The thiol (-SH) functional group is found in a number of drug compounds and confers a unique combination of useful properties. Thiol-containing drugs can reduce radicals and other toxic electrophiles, restore cellular thiol pools, and form stable complexes with heavy metals such as lead, arsenic, and copper. Thus, thiols can treat a variety of conditions by serving as radical scavengers, GSH prodrugs, or metal chelators. Many of the compounds discussed here have been in use for decades, yet continued exploration of their properties has yielded new understanding in recent years, which can be used to optimize their clinical application and provide insights into the development of new treatments. The purpose of this narrative review is to highlight the biochemistry of currently used thiol drugs within the context of developments reported in the last five years. More specifically, this review focuses on thiol drugs that represent the standard of care for their associated conditions, including N-acetylcysteine, 2,3-meso-dimercaptosuccinic acid, British anti-Lewisite, D-penicillamine, amifostine, and others. Reports of novel dosing regimens, delivery strategies, and clinical applications for these compounds were examined with an eye toward emerging approaches to address a wide range of medical conditions in the future.

Changes in tissue gadolinium biodistribution measured in an animal model exposed to four chelating agents

PURPOSE

This study investigated the potential to reduce gadolinium levels in rodents after repetitive IV Gadodiamide administration using several chelating agents.

MATERIALS AND METHODS

The following six groups of rats were studied. Group 1: Control; Group 2: Gadodiamide only; Group 3: Meso-2,3-Dimercaptosuccinic acid (DMSA) + Gadodiamide; Group 4: N-Acetyl-L-cysteine (NAC) + Gadodiamide; Group 5: Coriandrum sativum extract + Gadodiamide; and Group 6: Deferoxamine + Gadodiamide. Brain, kidney, and blood samples were evaluated via inductively coupled plasma mass spectrometry. The brain was also evaluated histologically.

RESULTS

Kidney gadolinium levels in Groups 4 and 5 were approximately double that of Group 2 (p = 0.033 for each). There was almost no calcification in rat hippocampus for Group 4 rodents when compared with Groups 2, 3, 5 and 6.

CONCLUSION

Our preliminary study shows that excretion to the kidney has a higher propensity in NAC and Coriandrum sativum groups. It may be possible to change the distribution of gadolinium by administrating several agents. NAC may lower Gadodiamide-induced mineralization in rat hippocampus.

Cobalt chloride toxicity elicited hypertension and cardiac complication via induction of oxidative stress and upregulation of COX-2/Bax signaling pathway

Cobalt is a ferromagnetic metal with extensive industrial and biological applications. To assess the toxic effects of, and mechanisms involved in cobalt chloride (CoCl₂)-induced cardio-renal dysfunctions. Male Wistar rats were exposed orally, daily through drinking water to 0 ppm (control), 150 ppm, 300 ppm, and 600 ppm of CoCl₂, respectively. Following exposure, results revealed significant ( p < 0.05) rise in markers of oxidative stress, but decreased activities of catalase, glutathione peroxidase, glutathione-S-transferase, and reduced glutathione content in cardiac and renal tissues. There were significant increases in systolic, diastolic, and mean arterial blood pressure at the 300- and 600-ppm level of CoCl₂-exposed rats relative to the control. Prolongation of QT and QTc intervals was observed in CoCl₂ alone treated rats. Also, there were significant increases in the heart rates, and reduction in P wave, and PR duration of rats administered CoCl₂. Histopathology of the kidney revealed peritubular and periglomerular inflammation, focal glomerular necrosis following CoCl₂ exposure. Further, cyclooxygenase-2 and B-cell associated protein X expressions were upregulated in the cardiac and renal tissues of CoCl₂-exposed rats relative to the control. Combining all, results from this study implicated oxidative stress, inflammation, and apoptosis as pathologic mechanisms in CoCl₂-induced hypertension and cardiovascular complications of rats.

The Effect of Chitosan on the Erythrocyte Antioxidant Potential of Lead Toxicity-Induced Rats

In the present study, the effects of chitosan on erythrocyte malondialdehyde (MDA) and glutathione (GSH) levels and glutathione peroxidase (GSH-Px), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PDH) enzyme activities in lead toxicity-induced rats were investigated. Twenty-eight male Wistar albino rats were divided into four groups of control (C), lead group (Pb group), lead + chitosan group (Pb + CS group), and chitosan group (CS group). Lead groups were administered 50 mg/kg lead acetate intraperitoneally (ip) for 5 days and chitosan groups were administered 200 mg/kg chitosan for 28 days via gavage. At the end of the study, lead levels were measured in the blood; MDA and GSH levels and GPx, GR, and G6PDH activities were measured in the erythrocyte. It was determined that, in parallel with the increase of full blood lead levels in the Pb group, erythrocyte MDA levels increased significantly, while GSH levels and GSH-Px, GR, and G6PDH activities decreased when compared to those in the C and CS groups (p ˂ 0.05). There was a statistically significant decrease in lead and MDA levels and GSH level and GSH-Px activity increased (p ˂ 0.05) in the Pb + CS group, where chitosan was administered as a protective agent in addition to lead, when compared to the Pb group. There were no differences between the Pb + CS group and the other three groups based on GR and G6PDH activities (p ˃ 0.05). No statistically significant difference was found between the C and CS groups based on the parameters of analysis (p ˃ 0.05). The findings of the present study demonstrated that lead increased oxidative stress by increasing free radical production in erythrocytes, and chitosan was effective in removing the lead from the circulation and enforced the antioxidant defense system.

The consequence of NAC on sodium arsenite-induced uterine oxidative stress

Arsenic consumption through drinking water is a worldwide major health problem. Management of arsenic intoxication with invasive, painful therapy using metal chelators is usually used as a conventional treatment strategy in human. In this present study, we examined the efficacy of oral administration of N-acetyl l-cysteine (NAC) in limiting arsenic-mediated female reproductive disorders and oxidative stress in female Wistar rats. The treatment was continued for 8 days (2 estrus cycles) on rats with sodium arsenite (10 mg/Kg body weight) orally. We examined the electrozymographic imprint of three different enzymatic antioxidants in uterine tissue. Rats fed with sodium arsenite exhibited a significant lessening in the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx). Uterine DNA breakage, necrosis, ovarian and uterine tissue damage, disruption in steroidogenesis were also found in arsenic treated rats. Co-administration of NAC at different doses (50 mg/kg body weight, 100 mg/kg body weight, respectively) significantly reversed the action of uterine oxidative stress markers like malondialdehyde (MDA), conjugated dienes (CD) and non protein soluble thiol (NPSH); and noticeably improved antioxidant status of the arsenic fed rats. This ultimately resulted in the uterine tissue repairing followed by improvement of ovarian steroidogenesis. However, this effective function of NAC might be crucial for the restoration of arsenic-induced female reproductive organ damage in rats.

Erythrocytes as a biological model for screening of xenobiotics toxicity

Erythrocytes are the main cells in circulation. They are devoid of internal membrane structures and easy to be isolated and handled providing a good model for different assays. Red blood cells (RBCs) plasma membrane is a multi-component structure that keeps the cell morphology, elasticity, flexibility and deformability. Alteration of membrane structure upon exposure to xenobiotics could induce various cellular abnormalities and releasing of intracellular components. Therefore the morphological changes and extracellular release of haemoglobin [hemolysis] and increased content of extracellular adenosine triphosphate (ATP) [as signs of membrane stability] could be used to evaluate the cytotoxic effects of various molecules. The nucleated RBCs from birds, fish and amphibians can be used to evaluate genotoxicity of different xenobiotics using comet, DNA fragmentation and micronucleus assays. The RBCs could undergo programmed cell death (eryptosis) in response to injury providing a useful model to analyze some mechanisms of toxicity that could be implicated in apoptosis of nucleated cells. Erythrocytes are vulnerable to peroxidation making it a good biological membrane model for analyzing the oxidative stress and lipid peroxidation of various xenobiotics. The RBCs contain a large number of enzymatic and non-enzymatic antioxidants. The changes of the RBCs antioxidant capacity could reflect the capability of xenobiotics to generate reactive oxygen species (ROS) resulting in oxidative damage of tissue. These criteria make RBCs a valuable in vitro model to evaluate the cytotoxicity of different natural or synthetic and organic or inorganic molecules by cellular damage measures.

Prevalence of exposure of heavy metals and their impact on health consequences

Even in the current era of growing technology, the concentration of heavy metals present in drinking water is still not within the recommended limits as set by the regulatory authorities in different countries of the world. Drinking water contaminated with heavy metals namely; arsenic, cadmium, nickel, mercury, chromium, zinc, and lead is becoming a major health concern for public and health care professionals. Occupational exposure to heavy metals is known to occur by the utilization of these metals in various industrial processes and/or contents including color pigments and alloys. However, the predominant source resulting in measurable human exposure to heavy metals is the consumption of contaminated drinking water and the resulting health issues may include cardiovascular disorders, neuronal damage, renal injuries, and risk of cancer and diabetes. The general mechanism involved in heavy metal-induced toxicity is recognized to be the production of reactive oxygen species resulting oxidative damage and health related adverse effects. Thus utilization of heavy metal-contaminated water is resulting in high morbidity and mortality rates all over the world. Thereby, feeling the need to raise the concerns about contribution of different heavy metals in various health related issues, this article has discussed the global contamination of drinking water with heavy metals to assess the health hazards associated with consumption of heavy metal-contaminated water. A relationship between exposure limits and ultimate responses produced as well as the major organs affected have been reviewed. Acute and chronic poisoning symptoms and mechanisms responsible for such toxicities have also been discussed.

Mixture risk assessment due to ingestion of arsenic, copper, and zinc from milkfish farmed in contaminated coastal areas

Human health risks associated with the consumption of metal-contaminated fish over extended periods have become a concern particularly in Taiwan, where fish is consumed on a large scale. This study applied the interaction-based hazard index (HI) to assess the mixture health risks for fishers and non-fishers who consume the arsenic (As), copper (Cu), and zinc (Zn) contaminated milkfish from As-contaminated coastal areas in Taiwan, taking into account joint toxic actions and potential toxic interactions. We showed that the interactions of As-Zn and Cu-Zn were antagonistic, whereas As-Cu interaction was additive. We found that HI estimates without interactions considered were 1.3-1.6 times higher than interactive HIs. Probability distributions of HI estimates for non-fishers were less than 1, whereas all 97.5%-tile HI estimates for fishers were >1. Analytical results revealed that the level of inorganic As in milkfish was the main contributor to HIs, indicating a health risk posed to consumers of fish farmed in As-contaminated areas. However, we found that Zn supplementation could significantly decrease As-induced risk of hematological effect by activating a Zn-dependent enzyme. In order to improve the accuracy of health risk due to exposure to multiple metals, further toxicological data, regular environmental monitoring, dietary survey, and refinement approaches for interactive risk assessment are warranted.

Branched polyethylenimine-functionalized carbon dots as sensitive and selective fluorescent probes for N-acetylcysteine via an off–on mechanism

A novel fluorescence (FL) analytical method to determine N-acetylcysteine (NAC) was established by using a branched polyethyleneimine-functionalized carbon dot fluorescent system involving FL quenching by Cu²⁺ and subsequent FL recovery upon addition of NAC.

Circulating oxidative stress caused by Psoroptes natalensis infestation in Indian water buffaloes

The present study reports the circulating oxidative stress associated with Psoroptes natalensis infestation in Indian water buffaloes. Three non-descriptive water buffaloes, age ranging between 4 and 9 years, presented to Referral Veterinary Polyclinic, IVRI, for treatment served as clinical subject. The infested animals were treated with Ivermectin subcutaneously and Amitraz topically along with antioxidant like ascorbic acid, Vitamin E and selenium. The level of lipid peroxidase was significantly higher (3.94 ± 0.34) in Psoroptes infested buffalo and was reduced significantly (P ≤ 0.05) after treatment (1.56 ± 0.40). The significantly higher levels of MDA before treatment signify the role of lipid peroxide mediated skin lesions in P. natalensis infested buffaloes. Similarly the activities of the body antioxidant like GSH and CAT were significantly higher (P ≤ 0.05) after treatment. The less level of the body antioxidant (GSH) and reduced activities of the antioxidant enzymes like CAT and SOD before treatment imply that Psoroptes mite-infested buffaloes were in a state of significant oxidative stress. The study provides information on oxidative stress indices in P. natalensis infested buffaloes and gives additional insight regarding the pathogenesis of the disease and its management.

Prophylactic Effects of Garlic Oil and Onion Oil Fractions as Compared to Vitamin E on Rats Orally Fed with Lead Acetate Solution

Heavy metal pollution is a global public health challenge due to its stable and persistent environmental contamination. Of these lead is considered to be one of the most common ubiquitous and industrial pollutants and at low concentration it exerts extensive damages to the tissues. Daily feeding of lead acetate solution (Dose: 10 mg/kg/day) to normal rats for a month adversely altered the parameters of blood, serum and tissues, viz; RBC, WBC, Hb, ɗ- ALAD (Delta amino levulinic acid dehydratase), Pb content, lipids, oxidized lipids (TBARS), vitamins C and E and GSH levels and activities of AST, ALT and antioxidant enzymes viz; catalase, GR, Gpx and SOD. In order to study whether antioxidants have any effect to counteract the toxicity of lead we have selected comparatively better active allium fractions for the study viz: polar fraction of garlic (PFG) and polar fraction of onion (PFO). On feeding of these active fractions of garlic and onion oils i.e. their polar fractions and vitamin E (Dose 100 mg/kg/day) separately for a month along with or without lead acetate to rats each nutraceutical and vitamin E counteracted the adverse effects of Pb significantly (p ≤ 0.05). Their effects are in the order of PFG > PFO > Vitamin E. All these results point out that garlic and onion oils contain natural disulfoxide compounds which act as antioxidant and anti toxic to lead compounds. Their comparative differences in action may be due to the presence and position of double bonds and disulfide oxide bonds in their molecules. i.e., in PFG the allyl disulfide oxide group is present and in PFO saturated methyl and propyl groups and unsaturated propenyl group are present in place of allyl groups. The former group confers a better antioxidant activity on PFG, while the latter groups confer a lesser activity on PFO.

Severe Abdominal Pain Caused by Lead Toxicity without Response to Oral Chelators: A Case Report

A 19-year-old woman was referred to the Emergency Surgery Department with severe abdominal pain, icterus, and anemia. The patient’s clinical and paraclinical findings in addition to her occupational and social history, convinced us to assay blood lead level (BLL), which was 41/5 μg/dL. Therefore toxicology consult was performed to treat lead toxicity.

Recheck of the BLL showed the level as 53/7 μg/dL. So oral chelator with succimer was started. Despite consumption of oral chelator, there was no response and the pain continued. Because our repeated evaluations were negative, we decided to re-treat lead poisoning by intravenous and intramuscular chelators. Dimercaprol (BAL) + calcium EDTA was started, and after 5 days, the pain relieved dramatically and the patient was discharged.

We recommend more liberal lead poisoning therapy in symptomatic patients, and also suggest parenteral chelator therapy, which is more potent, instead of oral chelators in patients with severe symptoms.

Honey prevents neurobehavioural deficit and oxidative stress induced by lead acetate exposure in male Wistar rats- a preliminary study

This research sought to investigate the possible neuroprotective effects of honey against lead (Pb)-induced neurotoxicity. Twenty four male Wistar rats were divided into four groups: Control group that received 1 ml/kg distilled orally for 28 days; while groups II-IV received 0.2% lead in drinking water and 1 ml/kg of distilled water, 1 ml/kg of honey, 1.5 ml/kg of honey respectively for 28 days. Anxiety and exploratory activities were determined in the open field test. Memory function was determined using Morris water maze after which the animals were sacrificed. The brains were then excised, homogenized and Lipid peroxidation (MDA), Superoxide dismutase (SOD), Catalase, Glutathione (GSH) and Glutathione -S- Transferase (GST) activities were determined in the brains. Results showed that lead exposure causes decrease in locomotor and exploratory activities; increase anxiety, memory impairment, lipid peroxidation and decrease antioxidant activities. However, co-administration of honey with lead inhibited neurotoxicity as indicated by the improvement in memory function as evidenced by decreased latency period and increased in time spent in target quadrant in honey-fed rats compared to the lead-exposed animals. Furthermore, honey increased locomotion, exploration and decreased anxiety in lead-exposed rats as indicated by the frequency of rearing, freezing duration and the number of line crossed by animals. Also administration of honey improves antioxidant activities as shown by increased brain SOD, GST and GSH activities compared to the lead-treated groups but no significant effect on MDA level. It can be concluded that honey has neuroprotective effects against lead-induced cognitive deficit probably by enhancing antioxidant activities.

The lead accumulation and hematological findings in juvenile rock fish Sebastes schlegelii exposed to the dietary lead (II) concentrations

Juvenile rockfish (mean length 14.2 ± 1.9 cm, and mean weight 57.3 ± 5.2g) were exposed for 4 weeks with the different levels of dietary lead (Pb(2+)) at 0, 30, 60, 120 and 240 mg/L. The exposure concentration and period of Pb have induced significant amount of it the specific tissues of rockfish. The highest Pb accumulation was observed in the kidney tissue by the dietary lead exposure. The growth rate and hepatosomatic index were considerably inhibited over 120 mg/kg. The hematological parameters such as red blood cell (RBC) counts, hematocrit (Ht) value, and hemoglobin (Hb) concentration were significantly decreased over 60 mg/kg Pb concentration. In the inorganic components, the values of calcium and magnesium in plasma were significantly decreased. The glucose and cholesterol values were notably increased, whereas total protein was decreased. The enzyme components, glutamic oxalate transaminase (GOT) and glutamic pyruvate transaminase (GPT), were significantly elevated by the dietary lead exposure, but no change was observed in alkaline phosphatase (ALP).

Assessment of oxidative stress in hippocampus, cerebellum and frontal cortex in rat pups exposed to lead (Pb) during specific periods of initial brain development

Epidemiological studies in children have proved that lead (Pb) exposure causes deficits in neural and cognitive functions. The present study assessed the oxidative stress on postnatal day 30, in the hippocampus, cerebellum and frontal cortex of rat pups exposed to Pb during specific periods of early brain development. Five groups of rat pups were investigated, and 0.2% Pb acetate in drinking was the dosage used. (i) Gestation and lactation (GL) group (n = 9) of rat pups was exposed to Pb during gestation and lactation through their mother, (ii) gestation (G) group (n = 9) of rat pups was exposed to Pb during gestation only, (iii) lactation (L) group (n = 9) of rat pups was exposed to Pb during lactation only, (iv) pre-gestation (PG) group (n = 9) of rat pups was born to mothers who were exposed to Pb for 1 month before conception, and (v) normal control (NC) (n = 9) group of rats pups had no exposure to Pb during gestation and lactation period. From the present study, it is evident that Pb exposure during different periods of early brain development (GL, G, L and PG groups) causes oxidative stress and lactation period (postnatal period) of Pb exposure produces maximum oxidative stress.

Effect of N-acetylcysteine administration on homocysteine level, oxidative damage to proteins, and levels of iron (Fe) and Fe-related proteins in lead-exposed workers

N-Acetylcysteine (NAC) could be included in protocols designed for the treatment of lead toxicity. Therefore, in this study, we decided to investigate the influence of NAC administration on homocysteine (Hcy) levels, oxidative damage to proteins, and the levels of iron (Fe), transferrin (TRF), and haptoglobin (HPG) in lead (Pb)-exposed workers. The examined population (n = 171) was composed of male employees who worked with Pb. They were randomized into four groups. Workers who were not administered any antioxidants, drugs, vitamins, or dietary supplements were classified as the reference group (n = 49). The remaining three groups consisted of workers who were treated orally with NAC at three different doses (1 × 200, 2 × 200, or 2 × 400 mg) for 12 weeks. After the treatment, blood Pb levels significantly decreased in the groups receiving NAC compared with the reference group. The protein concentration was not affected by NAC administration. In contrast, Hcy levels significantly decreased or showed a strong tendency toward lower values depending on the NAC dose. Levels of the protein carbonyl groups were significantly decreased in all of the groups receiving NAC. Conversely, glutamate dehydrogenase activity was significantly elevated in all of the groups receiving NAC, while the level of protein thiol groups was significantly elevated only in the group receiving 200 mg of NAC. Treatment with NAC did not significantly affect Fe and TRF levels, whereas HPG levels showed a tendency toward lower values. Treatment with NAC normalized the level of Hcy and decreased oxidative stress as measured by the protein carbonyl content; this effect occurred in a dose-dependent manner. Moreover, small doses of NAC elevated the levels of protein thiol groups. Therefore, NAC could be introduced as an alternative therapy for chronic Pb toxicity in humans.

Chronic effects of environmentally-relevant concentrations of lead in Pelophylax nigromaculata tadpoles: Threshold dose and adverse effects

Lead (Pb) is a common heavy metal in the natural environment, but its concentration has been increasing alongside widespread industrial and agricultural development in China. The dark-spotted frog Pelophylax (formerly Rana) nigromaculata (Anura: Ranidae) is distributed across East Asia and inhabits anthropogenic habitats such as farmland. Here, P. nigromaculata tadpoles (Gosner stage 19-46) were exposed to Pb at different concentrations (0, 40, 80, 160, 320, 640 and 1280µg/L) and Pb-induced survival, metamorphosis time, development, malformations, mobility and gonad structure were monitored. The results showed that above the threshold concentration of Pb, adverse effects were obvious. As the concentration of Pb increased, the adverse effects on different traits followed different patterns: the effects on hindlimb length, survival rate, metamorphosis rate, total malformation rate, swimming speed and jumping speed largely exhibited a linear pattern; the effects on snout-vent length, body mass and forelimb length largely exhibited a bimodal pattern. Sex ratio and gonadal histology were not affected by Pb, suggesting that Pb is not strongly estrogenic in P. nigromaculata.

Effect of N-acetylcysteine administration on the expression and activities of antioxidant enzymes and the malondialdehyde level in the blood of lead-exposed workers

We investigated whether treatment with N-acetylcysteine (NAC) reduces oxidative stress intensity and restores the expression and activities of superoxide dismutase (Sod1, SOD), catalase (Cat, CAT) and glutathione peroxidase (Gpx1, GPx) in lead-exposed workers. The exposed population was divided randomly into two groups. Workers in the first group (reference group, n=49) were not administered any drugs, while workers in the second group (n=122) were treated with NAC at three doses for 12 weeks (200 mg, 400 mg, 800 mg/day). NAC administered orally to lead-exposed workers normalized antioxidant enzyme activities in blood cells. Oxidative stress intensity measured as malondialdehyde (MDA) levels in serum, leukocytes and erythrocytes significantly decreased after NAC administration. NAC may be an alternative therapy for chronic lead intoxication.

Effects of heavy metals on biomarkers for oxidative stress in Griffon vulture (Gyps fulvus)

Metals are involved in the formation of reactive oxygen species (ROS) which may result in metal-related oxidative stress that can lead to oxidative damage to lipids, DNA and proteins. It is necessary to understand the mechanisms of metal toxicity in wild birds, and the concentrations that cause effects on oxidative stress biomarkers. The aim of this study is to assess the concentrations of lead (Pb), cadmium (Cd), mercury (Hg), copper (Cu) and zinc (Zn) with regards to oxidative stress in blood samples of 66 Griffon vultures (Gyps fulvus) from two areas of the Autonomous Community of Valencia (East of Spain). The two study areas (Alcoy n=36 and Cinctorres n=30) were selected as random locations of interest that had not yet been studied, and are feeding stations where supplementary food, mainly of pork origin, is provided for vultures. Given that the two study areas are not considered polluted sites, we expected to find low metal concentrations. However, there are no known threshold concentrations at which metals can affect antioxidant systems, and low metal levels may have an effect on antioxidant biomolecules. In this study, since sampling was done at the beginning of the hunting season, the low Pb levels found in most Griffon vultures from Alcoy and Cinctorres (median=12.37 and 16.26μg/dl, respectively) are suggestive of background levels usually found in vultures that feed on pork carcasses all year round. The ingestion of game meat with bullet fragments in carcasses or with Pb shots embedded in the flesh could be the cause of the high blood Pb concentrations found in three vultures from Cinctorres (83, 290 and 362μg/dl). Griffon vultures feeding in Cinctorres had enhanced CAT and GST activities and tGSH concentrations, which may be interpreted as protective response against the higher TBARS levels. This study provides threshold concentrations at which metals affect antioxidant system derived from 66 samples of Griffon vulture. Blood Cd concentrations greater than 0.05μg/dl produced an induction of 33% in GPx and of 44% in CAT activity in erythrocytes of vultures from Alcoy. Hg concentrations in blood higher than 3μg/dl produced an induction of 10% in SOD activity. Concentrations of Pb above 15µg/dl in blood produced an inhibition of 12.5% in GPx and 11.3% in CAT activity, and a TBARS induction of 10.7% in erythrocytes of Griffon vultures.

Cholestasis and seizure due to lead toxicity: a case report

INTRODUCTION

Lead poisoning is a major public health risk which may involve major organs. Recently, there have been reports of opioid adulteration with lead in Iran. The following case report is the first of its kind in that intrahepatic cholestasis due to lead toxicity has been described.

CASE PRESENTATION

A 65-year-old man presented to the emergency department with abdominal pain, abnormal liver function tests (cholestatic pattern), and normocytic anemia. He had been an opium user for 20 years. Clinical and preclinical findings including the bluish discoloration of periodontal tissues, or Burton's sign, and generalized ileus on abdominal x-ray led us to the possibility of lead poisoning. Lead levels were higher than normal (150 μg/dL). Magnetic resonance cholangiopancreatography (MRCP) and abdominal ultrasound were performed to rule out extra hepatic causes of cholestasis. To evaluate the possibility of lead-induced hepatotoxicity, a liver biopsy was performed. Histological features of lead-induced hepatotoxity have rarely been described in humans. In this patient, focal canalicular cholestasis and mild portal inflammation were confirmed. Thus, treatment with ethylenediaminetetraacetic acid (EDTA) and British anti-lewisite (BAL) were initiated and continued for five days. The patient's liver function tests returned to their normal values, clinical findings including nausea, vomiting, and abdominal pain subsided, and the patient was discharged from the hospital in good condition.

CONCLUSIONS

Lead toxicity should always be taken into account in cases of intrahepatic cholestasis with an unknown etiology, especially in a setting where opium abuse is common.

Evaluation of protective effect of N-acetyl cysteine on arsenic-induced hepatotoxicity

OBJECTIVE

The present study was aimed to study protective role of N-acetyl cysteine (NAC) was assessed against arsenic (As)-induced hepatotoxicity in rats.

METHODS

Twenty four male Wistar rats were divided into 4 groups of 6 animals each and treated as follows: Group 1: sham control, 2: arsenic control (sodium arsenite @ 10 mg/kg b. wt orally for 4 wks), 3: Pre-treatment with NAC (@ 300 mg/kg orally for 2 wks) followed by sodium arsenite along with NAC (as per above doses) and 4: Sodium arsenite + NAC (as per above doses for 4 wks).

RESULTS

The concentration of thiobarbituric acid reacting substances (TBARS) and protein carbonyls was significantly (P<0.05) increased, while the concentration of reduced glutathione (GSH), and the activity of CYP450, Na+ - K+ ATPase and Mg2+ ATPase in liver were significantly (P<0.05) reduced in group 2 as compared to control. Groups 3 and 4 revealed improvement in the parameters in study.

CONCLUSION

The study revealed that arsenic induces hepatotoxicity by inducing oxidative stress and supplementation of NAC is beneficial in countering the adverse effects.

Protective effects of N-acetylcysteine on acetic acid-induced colitis in a porcine model

Background

Ulcerative colitis is a chronic inflammatory disease and involves multiple etiological factors. Acetic acid (AA)-induced colitis is a reproducible and simple model, sharing many characteristics with human colitis. N-acetylcysteine (NAC) has been widely used as an antioxidant in vivo and in vitro. NAC can affect several signaling pathways involving in apoptosis, angiogenesis, cell growth and arrest, redox-regulated gene expression, and inflammatory response. Therefore, NAC may not only protect against the direct injurious effects of oxidants, but also beneficially alter inflammatory events in colitis. This study was conducted to investigate whether NAC could alleviate the AA-induced colitis in a porcine model.

Methods

Weaned piglets were used to investigate the effects of NAC on AA-induced colitis. Severity of colitis was evaluated by colon histomorphology measurements, histopathology scores, tissue myeloperoxidase activity, as well as concentrations of malondialdehyde and pro-inflammatory mediators in the plasma and colon. The protective role of NAC was assessed by measurements of antioxidant status, growth modulator, cell apoptosis, and tight junction proteins. Abundances of caspase-3 and claudin-1 proteins in colonic mucosae were determined by the Western blot method. Epidermal growth factor receptor, amphiregulin, tumor necrosis factor-alpha (TNF-α), and toll-like receptor 4 (TLR4) mRNA levels in colonic mucosae were quantified using the real-time fluorescent quantitative PCR.

Results

Compared with the control group, AA treatment increased (P < 0.05) the histopathology scores, intraepithelial lymphocyte (IEL) numbers and density in the colon, myeloperoxidase activity, the concentrations of malondialdehyde and pro-inflammatory mediators in the plasma and colon, while reducing (P < 0.05) goblet cell numbers and the protein/DNA ratio in the colonic mucosa. These adverse effects of AA were partially ameliorated (P < 0.05) by dietary supplementation with NAC. In addition, NAC prevented the AA-induced increase in caspase-3 protein, while stimulating claudin-1 protein expression in the colonic mucosa. Moreover, NAC enhanced mRNA levels for epidermal growth factor and amphiregulin in the colonic mucosa.

Conclusion

Dietary supplementation with NAC can alleviate AA-induced colitis in a porcine model through regulating anti-oxidative responses, cell apoptosis, and EGF gene expression.

Release of N-acetylcysteine and N-acetylcysteine amide from contact lenses

OBJECTIVE

To investigate the use of contact lenses to release N-acetylcysteine (NAC) and N-acetylcysteine amide (NACA) that have frequently used for the treatment of some eye diseases.

METHODS

Three commercial contact lenses were used: Soflens Multi-Focal, 1-Day ACUVUE TruEye, and Frequency 55. All contact lenses were individually kept for 3 days in 10 mL of 3 mM NAC or NACA solutions in phosphate-buffered saline (PBS). After the loading period, the lenses were removed from the solution and put into 5 mL of PBS for 3 days (static mode). During this period, samples were taken at specified times and analyzed by high-pressure liquid chromatography.

RESULTS

From the release profiles of NAC and NACA, it was found that both NAC and NACA could be released from the lenses within 72 hours. Frequency 55 released 95.9%±2.7% of loaded NAC and 60.0%±2.1% of loaded NACA in 24 hours, whereas 1-Day ACUVUE TruEye released 80.9%±1.2% of loaded NAC and 54.0%±1.9% of loaded NACA and Soflens Multi-Focal released 72.8%±2.8% of loaded NAC and 51.9%±2.3% of loaded NACA during that same period.

CONCLUSIONS

The lenses could achieve the appropriate delivery of drugs during their intended time of wear. The amount of released NACA was less than that of NAC because of the more hydrophobic structure of NACA. According to the power law, the values of the exponential constant n were found to be below 0.5, indicating that the behavior observed was "less Fickian".

Trace minerals status and antioxidative enzyme activity in dogs with generalized demodecosis

The present study was aimed to determine the levels of trace elements zinc, copper, iron, erythrocyte oxidant/anti-oxidant balance, vitamin C and β-carotene in dogs with generalized demodecosis. A total of 24 dogs with clinically established diagnosis of generalized demodecosis and 6 dogs as control were included in the study. In comparison to healthy control, zinc and copper levels were significantly (P<0.01) lower in dogs with generalized demodecosis, whereas iron levels were significantly (P<0.01) higher. Malondialdehyde (MDA) levels were significantly (P<0.01) higher in diseased dogs whereas activity of superoxide dismutase (SOD) and catalase were significantly (P<0.01) lower. β-carotene and vitamin C levels were significantly (P<0.05) lower in diseased dogs when compared to healthy control. SOD activity was positively correlated with zinc (rs=0.65, rs=0.71 and P<0.05) and copper (rs=0.51, rs=0.63 and P<0.05) in both healthy and diseased dogs. MDA levels were negatively correlated with iron (rs=-0.49, rs=-0.78 and P<0.05), β-carotene (rs=-0.26, P>0.05; rs=-0.54, P<0.05, respectively) in both healthy and diseased dogs and with SOD activity in diseased dogs only (rs=-0.68, P<0.05). From the present study, it was concluded that generalized demodecosis in dogs is associated with significant alteration in trace elements and oxidant/anti-oxidant imbalance and this imbalance might be secondary to changes caused by demodectic mange.

The metabolism of carbohydrates and lipid peroxidation in lead-exposed workers

The present study was undertaken to estimate the effect of occupational exposure to lead on the blood concentration of glucose and several enzymes involved in glycolysis, the citric acid cycle, and the pentose phosphate pathway. To estimate the degree of lipid peroxidation, the concentrations of conjugated dienes were determined.

The examined group included 145 healthy male employees of lead–zinc works. Taking into account the mean blood lead levels, the examined group was divided into two subgroups. The control group was composed of 36 healthy male administrative workers.

The markers of lead exposure were significantly elevated in both subgroups when compared with the controls. There were no significant changes in fasting glucose concentration and fructose-1,6-bisphosphate aldolase activity in the study population. The concentration of conjugated dienes was significantly higher in both subgroups, whereas the activity of malate dehydrogenase was significantly higher only in the group with higher exposure. The activities of lactate dehydrogenase and sorbitol dehydrogenase were significantly decreased in the examined subgroups. The activity of glucose-6-phosphate dehydrogenase decreased significantly in the group with higher exposure and could be the cause of the elevated concentrations of conjugated dienes.

It is possible to conclude that lead interferes with carbohydrate metabolism, but compensatory mechanisms seem to be efficient, as glucose homeostasis in lead-exposed workers was not disturbed.

The administration of N-acetylcysteine reduces oxidative stress and regulates glutathione metabolism in the blood cells of workers exposed to lead

CONTEXT AND OBJECTIVE

The aim of the study was to investigate whether treatment with N-acetylcysteine (NAC) is able to restore erythrocyte glutathione (GSH) content in workers exposed to lead. Additionally, we measured the leukocyte and erythrocyte activities of GSH-related enzymes, such as glutathione reductase (GR), glutathione-S-transferase (GST), and glucose-6-phosphate dehydrogenase (G6PD), and estimated the influence of NAC administration on oxidative stress intensity, which was measured as the lipofuscin (LPS) level in erythrocytes.

METHODS

The exposed population consisted of 171 healthy males randomly divided into four groups. Workers in the first group (n = 49) were not administered any antioxidants, drugs, vitamins, or dietary supplements, while workers in the remaining groups were treated with NAC at three doses for 12 weeks (1 × 200 mg per day, 2 × 200 mg per day, and 2 × 400 mg per day). All workers continued to work during the study. The blood of all examined workers was drawn two times: at the beginning of the study and after 12 weeks of treatment.

RESULTS AND CONCLUSION

Blood lead levels decreased significantly in all groups receiving NAC compared to those in baseline. Erythrocyte GSH concentrations were significantly elevated in workers receiving 400 and 800 mg of NAC compared to those in baseline by 5% and 6%, respectively. Erythrocyte G6PD activity was significantly elevated in workers receiving 200, 400, and 800 mg of NAC compared to those in baseline by 24%, 14%, and 14%, respectively. By contrast, there were no significant differences in leukocyte G6PD or leukocyte and erythrocyte glutathione reductase (GR) activities before and after treatment. Leukocyte GST activities decreased significantly after treatment in workers receiving 200 mg of NAC by 34%, while LPS levels decreased significantly in workers receiving 200, 400, and 800 mg of NAC compared to those in baseline by 5%, 15%, and 13%, respectively. In conclusion, NAC decreases oxidative stress in workers exposed to lead via stimulating GSH synthesis.

Optical nanosphere sensor based on shell-by-shell fabrication for removal of toxic metals from human blood

Because toxic heavy metals tend to bioaccumulate, they represent a substantial human health hazard. Various methods are used to identify and quantify toxic metals in biological tissues and environment fluids, but a simple, rapid, and inexpensive system has yet to be developed. To reduce the necessity for instrument-dependent analysis, we developed a single, pH-dependent, nanosphere (NS) sensor for naked-eye detection and removal of toxic metal ions from drinking water and physiological systems (i.e., blood). The design platform for the optical NS sensor is composed of double mesoporous core-shell silica NSs fabricated by one-pot, template-guided synthesis with anionic surfactant. The dense shell-by-shell NS construction generated a unique hierarchical NS sensor with a hollow cage interior to enable accessibility for continuous monitoring of several different toxic metal ions and efficient multi-ion sensing and removal capabilities with respect to reversibility, longevity, selectivity, and signal stability. Here, we examined the application of the NS sensor for the removal of toxic metals (e.g., lead ions from a physiological system, such as human blood). The findings show that this sensor design has potential for the rapid screening of blood lead levels so that the effects of lead toxicity can be avoided.