The effect of lead acetate on oxidative stress and antioxidant status in rat bronchoalveolar lavage fluid and lung tissue

Dietary Nannochloropsis oculata ameliorates lead acetate induced reproductive toxicity in Barki rams: NF-κB and cytokines pathways

The study aimed to explore the protective effect of Nannochloropsis oculata (N.oculata) on lead induced reproductive toxicity in rams. Sixteen Barki rams were divided equally in to 4 groups; group A: control, group B: was administered 3 % dietary N. oculate, group C: was gavaged 5 mg/kg/day lead acetate and group D: was supplemented with 3 % dietary N. oculata and gavaged with 5 mg/kg/day lead acetate. The experiment lasted 180 days. Semen and blood samples were obtained. Ejaculates were examined for semen criteria besides, analysis of testosterone. Testicular oxidant/antioxidant markers, cytokines, gene expression of interleukin-6 (IL-6) and nuclear factor Kappa B (NF-κB) were estimated. Alga-treated rams revealed significant upgrades in semen criteria, serum testosterone and reduced glutathione (GSH); meanwhile, downregulation in malondialdehyde (MDA), IL-4, IL-2 as well as gene expressions of IL-6 and NF-κB as compared to other treated groups. However, lead-treated rams showed significant deteriorations in semen criteria and reduced GSH while significant elevations in MDA, IL-4, IL-2 as well as gene expression of IL-6 and NF-κB were noticed than control. Alga supplementation to lead-intoxicated rams significantly upgraded the lead induced alterations that were manifested by improvement in testicular histopathology. In conclusion, the addition of alga mitigated lead induced reproductive toxicity in rams via improving testosterone, oxidant/antioxidant status, semen criteria and reducing inflammatory cytokines.

Involvement of Nrf2 Signaling in Lead-induced Toxicity

Nuclear factor erythroid 2-related factor 2 (Nrf2) is used as one of the main protective factors against various pathological processes, as it regulates cells resistant to oxidation. Several studies have extensively explored the relationship between environmental exposure to heavy metals, particularly lead (Pb), and the development of various human diseases. These metals have been reported to be able to, directly and indirectly, induce the production of reactive oxygen species (ROS) and cause oxidative stress in various organs. Since Nrf2 signaling is important in maintaining redox status, it has a dual role depending on the specific biological context. On the one hand, Nrf2 provides a protective mechanism against metal-induced toxicity; on the other hand, it can induce metalinduced carcinogenesis upon prolonged exposure and activation. Therefore, the aim of this review was to summarize the latest knowledge on the functional interrelation between toxic metals, such as Pb and Nrf2 signaling.

Role of Nrf2 in bisphenol effects: a review study

Bisphenols (BPs), the main endocrine-disrupting chemicals used in polycarbonate plastics, epoxy-phenol resins, and some other manufacturers, have been interestingly focused to find their toxic effects in recent years. Due to the strong relation between bisphenols and some crucial receptors such as ERs, AR, glucocorticoid receptor, THRs, ERRs, hPXR, AhR, and etcetera, the disrupting and oncogenic role of these chemicals on reproductive, respiratory, and circulatory systems and a broad group of body tissues have been investigated. BPs induce oxidant enzymes, exert antioxidant enzymes from body cells, and result in the expression of proinflammatory genes, leading to cell apoptosis and inflammation. To maintain the homeostasis of human body cells, Nrf2, the key regulator of oxidative stress (Ashrafizadeh et al., 2020a; Ashrafizadeh et al., 2020c; Boroumand et al., 2018), confronts BP-induced ROS and RNS through the activation of antioxidant enzymes such as SOD1/2, CAT, GSH, GPX, HO-1, and etcetera. Chemicals and drugs such as LUT, NAC, GEN, L-NMMA, Ph₂Se₂, and GE can regulate the interactions between BPs and Nrf2. Despite the vital role of controlled levels of Nrf2 as an anti-inflammatory and antiapoptotic element, the uncontrolled activity of this transcription factor could lead to cell proliferation and tumorigenesis through NQO1, SLC7a11, Gclm, HMOX1, NQO1 gene activation, and some other genes. To avoid the excessive activity of Nrf2, some protein complexes like CUL3-RBX1-Keap1 (as the primary regulator), β-TrCP, and WDR23 regulate Nrf2's function. It is necessary to note that BPA, as the most famous member, is further reviewed due to its resemblance to the bisphenol family to each other.

Intrauterine exposure of mice to arsenite induces abnormal and transgenerational glycometabolism

The adverse, transgenerational effects on health caused by environmental pollutants are receiving increasing attention. For humans and mice, inorganic arsenic (iAs), a widespread environmental contaminant, is associated with diabetic phenotypes. However, the transgenerational effects of arsenite-induced changes in glucose metabolism in mice have not been fully investigated. In the present study, F0 pregnant mice were exposed to arsenite via drinking water (0, 0.5, 5, or 50 ppm NaAsO₂) from gestational day 0 (GD0) until parturition. We examined the effects of arsenite exposure on the metabolic phenotypes and the levels of proteins and genes related to glucose metabolism of dams and their offspring (F1∼F4). Arsenite exposure altered the glucose tolerance of offspring. Notably, glucose transporter-2 (GLUT2) and insulin receptor substrate-1 (IRS1), which are related to the maintenance of glucose homeostasis, were also changed. The homeostasis assessment-insulin resistance (HOMA-IR), an indicator of insulin resistance, was higher in the offspring from the F0 female mice exposed to arsenite. Furthermore, imprinted genes, insulin-like growth factor 2 (IGF2) and potassium voltage-gated channel subfamily Q member 1 (KCNQ1), related to glycometabolism across multiple generations, were lower in the offspring. In sum, arsenite exposure during pregnancy transgenerationally affects glucose metabolism, which is related to altered levels of IGF2 and KCNQ1.

Pb and Cd exposure linked with Il-10 and Il-13 gene polymorphisms in asthma risk relevant immunomodulation in children

Genetic variants and environmental factor of heavy metal exposure accelerate the risk of immune-mediated respiratory diseases, including asthma in children. This study aims to investigate the effects and interaction of Pb, Cd exposure from e-waste and interleukin (IL)-10, IL-13 gene polymorphisms on interleukin expressions in children. Pb, Cd levels, Il-10 (rs1800871, rs1800872, rs1800896) and Il-13 (rs20541, rs1800925) polymorphisms were determined in blood or urine of 155 children (75 from e-waste-exposed area, Guiyu and 80 from reference area, Haojiang). Blood Pb and urine Cd levels of e-waste-exposed children were both higher (mean: 5.89 vs. 3.35 μg/dL; 6.04 vs. 1.82 μg/g, both P < 0.05). Exposed children had a larger proportion of high blood Pb level (> 5.00 μg/dL) (66.67% vs. 4.11%, P < 0.001), but they had no statistically different proportion of high urine Cd level (> 1.00 μg/g creatinine). Median levels of IL-13 decreased (3.674 vs. 4.410 ng/L, P < 0.01), but of IL-10 did not vary in serum of exposed children. The analyses revealed no significant associations of Pb or Cd with Il-10 or Il-13 gene polymorphisms. The high blood Pb and urine Cd level were respectively associated with the low IL-13 ( < 3.696 ng/L) and low IL-10 ( < 0.361 ng/L) level, after adjustment for children's age, gender, and BMI (both P ≤ 0.05). Children homozygous carrying major allele for Il-13 (rs20541 and rs1800925) had additive interactions with high blood Pb level on low IL-13 expression (OR = 5.37, 95% CI: 1.96, 14.73 and OR = 8.45, 95% CI: 2.61, 27.32; both P ≤ 0.001). In contrast, no interaction was observed amongst Pb or Cd with Il-10 gene polymorphisms on its expression. Our findings suggest that Pb exposure interacting with Il-13 gene polymorphisms negatively regulates IL-13 expression, which may pose a risk to abnormal asthma-relevant immunomodulation in preschool children.

A review study on the modulation of SIRT1 expression by miRNAs in aging and age-associated diseases

Sirtuin-1 (SIRT1) as a NAD + -dependent Class III protein deacetylase, involves in longevity and various cellular physiological processes. SIRT1 via deacetylating transcription factors regulates cell growth, inflammation, metabolism, hypoxic responses, cell survival, senescence, and aging. MicroRNAs (miRNAs) are short non-coding RNAs that modulate the expression of target genes in a post-transcriptional manner. Recent investigations have exhibited that miRNAs have an important role in regulating cell growth, development, stress responses, tumor formation and suppression, cell death, and aging. In the present review, we summarize recent findings about the roles of miRNAs in regulating SIRT1 and SIRT1-associated signaling cascade and downstream effects, like apoptosis and aging. Here we introduce and discuss how activity and expression of SIRT1 are modulated by miRNAs and further review the therapeutic potential of targeting miRNAs for age-associated diseases that involve SIRT1 dysfunction. Although at its infancy, research on the roles of miRNAs in aging and their function through modulating SIRT1 may provide new insights in deciphering the key molecular pathways related to aging and age-associated disorders.

Anti-Inflammatory Activity of Melatonin: a Focus on the Role of NLRP3 Inflammasome

Melatonin is a hormone of the pineal gland that contributes to the regulation of physiological activities, such as sleep, circadian rhythm, and neuroendocrine processes. Melatonin is found in several plants and has pharmacological activities including antioxidant, anti-inflammatory, hepatoprotective, cardioprotective, and neuroprotective. It also has shown therapeutic efficacy in treatment of cancer and diabetes. Melatonin affects several molecular pathways to exert its protective effects. The NLRP3 inflammasome is considered a novel target of melatonin. This inflammasome contributes to enhanced level of IL-1β, caspase-1 activation, and pyroptosis stimulation. The function of NLRP3 inflammasome has been explored in various diseases, including cancer, diabetes, and neurological disorders. By inhibiting NLRP3, melatonin diminishes inflammation and influences various molecular pathways, such as SIRT1, microRNA, long non-coding RNA, and Wnt/β-catenin. Here, we discuss these molecular pathways and suggest that melatonin-induced inhibition of NLRP3 should be advanced in disease therapy.

Curcumin Activates the Nrf2 Pathway and Induces Cellular Protection Against Oxidative Injury

Curcumin is a naturally occurring polyphenol that is isolated from the rhizome of Curcuma longa (turmeric). This medicinal compound has different biological activities, including antioxidant, antibacterial, antineoplastic, and anti-inflammatory. It also has therapeutic effects on neurodegenerative disorders, renal disorders, and diabetes mellitus. Curcumin is safe and well-tolerated at high concentrations without inducing toxicity. It seems that curcumin is capable of targeting the Nrf2 signaling pathway in protecting the cells against oxidative damage. Besides, this strategy is advantageous in cancer therapy. Accumulating data demonstrates that curcumin applies four distinct ways to stimulate the Nrf2 signaling pathway, including inhibition of Keap1, affecting the upstream mediators of Nrf2, influencing the expression of Nrf2 and target genes, and finally, improving the nuclear translocation of Nrf2. In the present review, the effects of curcumin on the Nrf2 signaling pathway to exert its therapeutic and biological activities has been discussed.

Ameliorative effect of L-carnitine on chronic lead-induced reproductive toxicity in male rats

Lead toxicity is one of the causative agents of male infertility that raised concern from environmental contamination worldwide. L‐carnitine, a biologically active amino acid, present in high concentration in the reproductive organs such as the epididymis, is involved in sperm maturation. The possible protective effect of L‐carnitine in experimentally lead‐induced male reproductive toxicity in rats was evaluated in this study. Thirty adult male Wistar rats were divided into three groups. Group 1: the negative control group was treated with normal saline; Group 2: exposed to 50 mg/kg lead acetate (2% solution in saline); and Group 3: treated with lead acetate 50 mg/kg (2% solution in saline) + L‐carnitine 100 mg/kg. At the end of the experimental period, body and testicular weights were determined, blood samples were withdrawn for hormonal assays of FSH, LH and testosterone. Sperm parameters as sperm count, morphology, viability and motility were measured. Testicular tissue homogenates were prepared for enzymatic assays and for measuring oxidative stress parameters. Lead significantly increased both oxidative stress and the concentration of lactate dehydrogenase‐C in the testicular tissues with a decrease in sperm count, motility and viability. Lead acetate treatment, induced alteration in sperms with normal morphology together with reductions in the serum FSH, LH, testosterone, body and testicular weights. The concentration of 17β‐hydroxysteroid dehydrogenase was significantly reduced. Co‐administration of L‐carnitine significantly reduced testicular oxidative stress, improved sperm parameters, elevated serum FSH, LH and testosterone with an insignificant reduction in the testicular weight. The concentrations of 17β‐hydroxysteroid dehydrogenase and lactate dehydrogenase‐C were significantly improved by L‐carnitine. The overall results indicate that L‐carnitine is expected to improve the lead acetate‐induced male reproductive toxicity.

New insights into the role of the Nrf2 signaling pathway in green tea catechin applications

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a transcriptional signaling pathway that plays a crucial role in numerous clinical complications. Pivotal roles of Nrf2 have been proved in cancer, autoimmune diseases, neurodegeneration, cardiovascular diseases, diabetes mellitus, renal injuries, respiratory conditions, gastrointestinal disturbances, and general disorders related to oxidative stress, inflammation, apoptosis, gelatinolysis, autophagy, and fibrogenesis processes. Green tea catechins as a rich source of phenolic compounds can deal with various clinical problems and manifestations. In this review, we attempted to focus on intervention between green tea catechins and Nrf2. Green tea catechins especially epigallocatechin gallate (EGCG) elucidated the protective role of Nrf2 and its downstream molecules in various disorders through Keap-1, HO-1, NQO-1, GPx, GCLc, GCLm, NF-kB cross-link, kinases, and apoptotic proteins. Subsequently, we compiled an updated expansions of the Nrf2 role as a gate to manage and protect different disorders and feasible indications of green tea catechins through this signaling pathway. The present review highlighted recent evidence-based data in silico, in vitro, and in vivo studies on an outline for future clinical trials.

Anti-tumor activity of resveratrol against gastric cancer: a review of recent advances with an emphasis on molecular pathways

Gastric cancer (GC) is one of the most common cancers with high malignancy. In spite of the great development in diagnostic tools and application of anti-tumor drugs, we have not witnessed a significant increase in the survival time of patients with GC. Multiple studies have revealed that Wnt, Nrf2, MAPK, and PI3K/Akt signaling pathways are involved in GC invasion. Besides, long non-coding RNAs and microRNAs function as upstream mediators in GC malignancy. GC cells have acquired resistance to currently applied anti-tumor drugs. Besides, combination therapy is associated with higher anti-tumor activity. Resveratrol (Res) is a non-flavonoid polyphenol with high anti-tumor activity used in treatment of various cancers. A number of studies have demonstrated the potential of Res in regulation of molecular pathways involved in cancer malignancy. At the present review, we show that Res targets a variety of signaling pathways to induce apoptotic cell death and simultaneously, to inhibit the migration and metastasis of GC cells.

Arsenite-induced transgenerational glycometabolism is associated with up-regulation of H3K4me2 via inhibiting spr-5 in caenorhabditis elegans

Arsenic (As) is a toxic element that is highly abundant in the environment. However, there has not been sufficient research into the mechanisms of arsenic-induced transgenerational effects. In biomedical and environmental toxicology research field, C. elegans are often used as the ideal model. In this study, F0 generation animals were cultured with arsenite, while subsequent generations animals (F1 - F6) were cultured in the absence of arsenic. Experiments were performed to examine the transgenerational glycometabolism and the associated mechanisms in all seven generations (F0 - F6) of C. elegans. Results show that arsenite exposure increased total glucose content but reduced glucose metabolites in F0 generation C. elegans. The total glucose content was also elevated in subsequent generations probably due to transgenerational downregulation of fgt-1. In addition, arsenite exposure induced transgenerational downregulation of histone demethyltransferase spr-5 and elevated histone dimethylation in F0 generation. This study highlights that single generation exposure to arsenite causes transgenerational changes in glycometabolism in C. elegans, which may be caused by downregulation of spr-5 and elevation of H3K4me2.

The effect of diosmin against lead exposure in rats‡

In this study, the effect of diosmin against the adverse effects of lead exposure in rats was investigated. Wistar Albino race 40 male rats weighing 150-200 g 2-3 months were used. A total of 4 groups were assigned, one of which was control and the other 3 were trial groups. The rats in the control group were treated with dimethyl sulfoxide, which was used only as a vehicle in diosmin administration. Groups 2, 3, and 4 from the experimental group were given diosmin at a dose of 50 mg/kg.bw, lead acetate at the dose of 1000 ppm, lead acetate at the dose of 1000 ppm, and diosmin at a dose of 50 mg/kg.bw for 6 weeks, respectively. Application of lead acetate with drinking water and also diosmin was performed by oral catheter. At the end of the experimental period, blood was taken to dry and with heparin by puncture to the heart under light ether anesthesia. Following the blood samples, some organs of the rats (the liver, kidney, brain, heart, and testis) were removed. Some biochemical parameters (glucose, triglyceride, cholesterol, BUN, creatinine, uric acid, LDH, AST, ALT, ALP, total protein, albumin) were measured in serum. Some oxidative stress parameters in tissue samples and blood (MDA, NO, SOD, CAT, GSH-Px, GSH) were evaluated. Body and organ (the liver, kidney, brain, heart, and testis) weights were also evaluated at the end of the study. No significant change was observed in the parameters examined in the diosmin alone-treated group by comparison to control group. On the other hand, significant changes were found in the values ​​of lead acetate-treated group comparing control group. It was observed that the values approached the values of the control group in the combination of lead and diosmin. Exposure to lead acetate at a dose of 1000 ppm for 6 weeks causes organ damage; however the diosmin application at a dose of 50 mg/kg.bw had a positive effect on the regression of tissue damage.

The role of NF-κB and AhR transcription factors in lead-induced lung toxicity in human lung cancer A549 cells

Lead (Pb) is recognized as the first heavy metal of the top six toxic air pollutants threatening human health and the second hazardous substance. Pb exposure is associated with lung impairment and high incidences of lung cancer. Nuclear factor kappa B (NF-κB) and aryl hydrocarbon receptor (AhR) signaling pathways are known to be expressed and play an important role in the lung. However, the link between Pb lung toxicity and NF-κB and/or AhR pathways remains unclear. This study was established to explore the role of NF-κB and AhR modulation in Pb-induced lung toxicity in human lung cancer A549 cells. In the current study, treatment of A549 cells with Pb significantly induced cell apoptosis as evidenced by increasing a) the percentage of cells underwent apoptosis determined by flow cytometry and b) p53 mRNA level. Pb treatment induced oxidative stress by a) increasing the formation of reactive oxygen species and b) decreasing GSTA1 mRNA levels. The toxic effects of Pb on the lung was associated with significant increases in NF-κB and AhR levels which was accompanied with increases in downstream targets genes, iNOS and CYP1A1, respectively. Inhibition of NF-κB or AhR either chemically using resveratrol or genetically using small interfering RNA (siRNA) significantly rescued A549 cells from Pb-mediated lung toxicity. The results clearly indicate that Pb-mediated lung toxicities are NF-κB and AhR-dependent mechanism.

The role of arsenic in obesity and diabetes

As many individuals worlwide are exposed to arsenic, it is necessary to unravel the role of arsenic in the risk of obesity and diabetes. Therefore, the present study reviewed the effects of arsenic exposure on the risk and potential etiologic mechanisms of obesity and diabetes. It has been suggested that inflammation, oxidative stress, and apoptosis contribute to the pathogenesis of arsenic-induced diabetes and obesity. Though arsenic is known to cause diabetes through different mechanisms, the role of adipose tissue in diabetes is still unclear. This review exhibited the effects of arsenic on the metabolism and signaling pathways within adipose tissue (such as sirtuin 3 [SIRT3]- forkhead box O3 [FOXO3a], mitogen-activated protein kinase [MAPK], phosphoinositide-dependant kinase-1 [PDK-1], unfolded protein response, and C/EBP homologous protein [CHOP10]). Different types of adipokines involved in arsenic-induced diabetes are yet to be elucidated. Arsenic exerts negative effects on the white adipose tissue by decreasing adipogenesis and enhancing lipolysis. Some epidemiological studies have shown that arsenic can promote obesity. Nevertheless, few studies have indicated that arsenic may induce lipodystrophy. Arsenic multifactorial effects include accelerating birth and postnatal weight gains, elevated body fat content, glucose intolerance, insulin resistance, and increased serum lipid profile. Arsenic also elevated cord blood and placental, as well as postnatal serum leptin levels. The data from human studies indicate an association between inorganic arsenic exposure and the risk of diabetes and obesity. However, the currently available evidence is insufficient to conclude that low-moderate dose arsenic is associated with diabetes or obesity development. Therefore, more investigations are needed to determine biological mechanisms linking arsenic exposure to obesity and diabetes.

The Neuroprotective Effects of Thymoquinone: A Review

Thymoquinone (TQ), one of the main components active of Nigella sativa, exhibited very useful biomedical effects such as anti-inflammatory, antioxidant, antimicrobial, antiparasitic, anticancer, hypoglycemic, antihypertensive, and antiasthmatic effects. There are several studies about pharmacological activities of TQ but its neuroprotection effects are not fully described. The literature search has indicated many studies pertaining to the effects of TQ in neurological problems such as epilepsy, parkinsonism, anxiety, and improvement of learning and memory, and so on. In addition, TQ protected brain cells from various injuries due to its antioxidant, anti-inflammatory, and apoptotic effects in cell line and experimental animal models. The present study has been designed to review the scientific literature about the pharmacological activities of TQ to the neurological diseases. This study purposed that although experimental studies indicated the beneficial effects of TQ against nervous system problems, better designed clinical trials in humans are needed to confirm these effects.

The Hepato-protective Effects of Portulaca oleracea L. extract: Review

BACKGROUND

Portulaca oleracea L. (Purslane) has been used in traditional medicine against hepatic injury, although its actual efficacy has not been fully understood. The present study aimed to critically review the recent literature data from 1990 to 2017 regarding the hepato-protective effects of Portulaca oleracea L. and its underlying mechanisms.

METHODS

Online literature resources were checked using different search engines such as Medline, PubMed, Iran Medex, Scopus, and Google Scholar to identify articles, editorials, and reviews about antidotal effects of Portulaca oleracea L. against hepatotoxic agents.

RESULTS

Few studies have indicated that Portulaca oleracea L. shows protective effects against hepatotoxic agents. However, due to lack of information in humans, more studies are needed to confirm the efficacy of Portulaca oleracea L. as a hepato-protective agent.

CONCLUSION

The study found that Portulaca oleracea L. may be effective on hepatotoxicity by modulating oxidative stress and inflammation.

Evaluation of oxidative stress in caprine bronchoalveolar lavage fluid of pneumonic and normal lungs

Research in the area of oxidative stress in pneumonic pathology still requires attention in small ruminants especially with the use of bronchoalveolar lavage (BAL) which may be a more sensitive indicator of respiratory diseases than blood. This investigation evaluates the role of oxidative stress in the pathogenesis of caprine pneumonia using BAL fluid (BALf) from healthy and pneumonic goats. A BALf from 192 goats (whose pneumonic histopathology had been characterized using standard techniques) was biochemically assayed for anti-oxidants and pro-oxidants. Malondialdehyde (MDA), hydrogen peroxide generation (H₂O₂), myeloperoxidase (MPO) and reduced glutathione (GSH) contents were measured to assess free radical activity in the BALf. Superoxide dismutase (SOD), Glutathione transferase (GST) and Glutathione peroxidase (GPx) activity were also determined colourimetrically. There were significant increases in the BALf supernatant of MDA, H₂O₂ and MPO with decreases in GSH level and SOD activity in the pneumonic goats (P < 0.05). There was also significant correlation of BALf oxidative assay to the type and severity of pneumonia. The levels of MDA, H₂O_2, and MPO increased significantly (P < 0.05) in bronchopneumonia and bronchointerstitial pneumonia than other pneumonic conditions and normal lungs. The management of caprine pneumonia should often incorporate antioxidant supplementation to correct the imbalance in pro-oxidant and anti-oxidant levels.

Anti-apoptotic role of spermine against lead and/or gamma irradiation-induced hepatotoxicity in male rats

Exposure to either lead (Pb) or γ-irradiation (IR) results in oxidative stress in biological systems. Herein, we explored the potential anti-apoptotic effect of spermine (Spm) against lead and/or γ-irradiation-induced hepatotoxicity in male albino rats. Rats were divided into eight experimental groups of ten rats each: groups including negative control, whole body γ-irradiated (6 Gray (Gy)), lead acetate (PbAct) trihydrate orally administered (75 mg/kg bw ≡ 40 mg/kg bw Pb for 14 consecutive days), and Spm intraperitoneally dosed (10 mg/kg bw for 14 consecutive days) rats and groups subjected to combinations of Pb + IR, Spm + IR, Spm + Pb, and Spm + Pb followed by IR on day 14 (Spm + Pb + IR). A significant decrease in arginase activity as well as mRNA and protein levels of Bcl-2 and p21 was observed in rats intoxicated with Pb and/or γ-irradiation compared to controls, whereas Bax mRNA and protein levels were significantly increased. Also, an increased level of nitric oxide (NO) with a reduced arginase activity was observed in liver tissues of intoxicated rats. Spm co-treatment with lead and/or γ-irradiation attenuated the increase in Bax mRNA and protein expression, while it restored those of Bcl-2 and p21 together with NO levels and arginase activity to control values. Altogether, we suggest that Spm may be useful in combating free radical-induced apoptosis in Pb-intoxicated and/or γ-irradiated rats.

Effect of LA on the Growth and Development of the Main Organs in Female Mice

Effects of lead acetate (LA) on the growth and development of major organs in female mice were studied. Female mice were divided randomly into four treatment groups and one control group. In treatment groups, mice were injected with different concentrations of LA solution every 2 days; whereas control-group mice received equal volumes of sterile normal saline. Body weight (BW) and symptoms were recorded every 2 days. After LA exposure, mice were executed by cervical dislocation and main organs (heart, liver, spleen, lung, kidney) collected for evaluation of morphologic and histologic changes. LA could greatly affect increases in BW, and BW decreased with increasing dose and time of exposure to LA. Compared with the control group, organ coefficients in treatment groups were of the order kidney and spleen > liver and lung > heart and demonstrated obvious dose-time effects. LA exposure could damage the heart, liver, spleen, lung, and kidney. Damage to the kidney and spleen was the most severe, followed by that to the liver, heart, and lung. Damage was aggravated with increasing doses and exposure time to LA in an obvious dose-time relationship; when LA dose was ≥20 mg/kg, the growth and development of mice were obviously inhibited. These results suggest that long-term exposure to low-dose LA can result in universal pathologic damage to mouse organs and that severity is dependent on the dose and duration of LA exposure.

Lead aggravates the diabetic-induced reproductive toxicity in male Wistar rats

Diabetes, an unresolved metabolic disorder, and lead contamination are prevalent problems in contemporary society. Previously, we have reported that either diabetes or lead exposure resulted in reproductive toxicity in male Wistar rats. The aim of this study was to evaluate whether diabetic rats exposed to lead demonstrate a higher degree of reproductive toxicity when compared with lead-exposed control rats. Diabetes was induced by injecting a single dose of streptozotocin (50 mg per kg body weight). Control and diabetic rats were exposed to lead at a concentration of 819 mg L-1 (0.15% lead acetate) through drinking water for a period of 30 days and assessed for reproductive and oxidative end points. The relative weights of the testes, epididymis, seminal vesicles, and the prostate gland were significantly decreased in diabetic rats. Daily sperm production, epididymal sperm count, motile, viable and HOS-tail swelled sperms, serum testosterone levels and testicular 3β- and 17β-hydroxysteroid dehydrogenase activity levels were significantly decreased in diabetic rats. Significant reductions in testicular and epididymal antioxidant enzyme activity levels and glutathione levels were observed in diabetic rats with an elevation in the levels of superoxide anions, hydrogen peroxides, and lipid peroxidation. A significant reduction in the number of implantations associated with elevated pre- and post-implantation losses was observed in females mated with diabetic males. Mild histopathological malformations were observed in the testis of the diabetic rats. Similar reproductive and oxidative toxicities were observed in lead-exposed control rats. Furthermore, lead exposed diabetic rats showed additional deterioration in reproductive end points and a noteworthy elevation in oxidative toxicity, suggesting that treatment with lead exacerbates reproductive toxicity in streptozotocin-induced diabetic rats.

Effect of crocin on aged rat kidney through inhibition of oxidative stress and proinflammatory state

This study evaluated whether crocin, a bioactive component of saffron, has a protective effect on kidney through reducing the oxidative stress and inflammatory response in aged rats. In this study the changes in activities of antioxidant enzymes, lipid peroxidation, glutathione (GSH) levels and the expression of pro-inflammatory cytokines in the serum and renal tissue were evaluated by ELISA and RT-PCR, respectively. The middle and aged rats were given intraperitoneal injections of crocin (10, 20, 30 mg/kg/day) for 4 weeks. After 4 weeks, animals were anesthetized with diethyl ether. The kidney samples were taken for biochemical analysis. The results revealed the aging was associated with a significant decrease in the activities of antioxidant enzymes, and GSH content with increase in lipid peroxidation level in kidney of the aged rats (p < 0.001). The increased levels of serum renal functional parameter, oxidative parameters (p < 0.01) and also pro-inflammatory cytokine levels were significantly reduced by crocin administration (p < 0.05). The aged rats exhibited a dysregulation of the oxidative stress, and inflammation in the kidneys, but crocin treatment significantly reduced the expression of the inflammatory genes. These results provide pivotal documentation that crocin has a renoprotective effects against the development of oxidative stress and inflammation in the kidney of old rats. Copyright © 2016 John Wiley & Sons, Ltd.

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.

Effect of chronic exposure to cadmium on serum lipid, lipoprotein and oxidative stress indices in male rats

Cadmium (Cd) is an environmental toxic metal implicated in lipid abnormalities. The present study was designed to elucidate the possible association between chronic exposure to Cd concentration and alterations in plasma lipid, lipoprotein, and oxidative stress indices in rats. Sixteen male rats were assigned to 2 groups of 8 rats each (test and control). The Cd-exposed group obtained drinking water containing cadmium chloride (CdCl2) in the concentration of 2.0 mg Cd/L in drinking water for 3 months. At the end of the experimental period, blood samples were obtained to determine the changes of serum triglycerides (TG), total cholesterol (TC), highdensity lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), reduced glutathione (GSH), malondialdehyde (MDA) and also serum Cd contents. The results of the present study indicated that Cd administration significantly increased the serum levels of TG, TC, LDL-C, MDA and Cd with reduction in the HDL-C and GSH levels. In conclusion, evidence is presented that chronic exposure to low Cd concentration can adversely affect the lipid and lipoprotein profile via lipid peroxidation.

Probit analysis of comparative assays on toxicities of lead chloride and lead acetate to in vitro cultured human umbilical cord blood lymphocytes

This work describes that cytotoxicity of lead chloride and lead acetate to in vitro cultured lymphocytes from human umbilical cord blood, using four monitoring methods namely, trypan blue staining, acridine orange/ethidium bromide staining, 3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyl tetrazolium bromide (MTT) and neutral red uptake assays; lead genotoxicity to lymphocytes was monitored by comet assay. The MIC value in each method was invariably 300 mg/L for PbCl₂. Lethal concentration₂₅ (LC₂₅) values were almost in an agreeable range: 691.83 to 831.76 mg/L; LC₅₀ values in each method were almost in the range: 1174.9 to 1348.9 mg/L; LC₁₀₀ values were in the range: 3000 to 3300 mg/L, for lead chloride. Similarly, The MIC value in each method were invariably 150 mg/L; LC₂₅ values were almost in the range: 295.12 to 371.53 mg/L; LC₅₀ values were in the range: 501.18 to 588.84 mg/L; LC₁₀₀ value was 1500 mg/L in all assays, for lead acetate. The comet assay also indicated that the LC₁₀₀ values were 3300 mg/L lead chloride and 1500 mg/L lead acetate. Thus, both cytotoxicity and genotoxicity were recorded at 3300 mg/L lead chloride and 1500 mg/L lead acetate with lymphocytes.

Associations of cadmium and lead exposure with leukocyte telomere length: findings from National Health and Nutrition Examination Survey, 1999-2002

Cadmium and lead are ubiquitous environmental contaminants that might increase risks of cardiovascular disease and other aging-related diseases, but their relationships with leukocyte telomere length (LTL), a marker of cellular aging, are poorly understood. In experimental studies, they have been shown to induce telomere shortening, but no epidemiologic study to date has examined their associations with LTL in the general population. We examined associations of blood lead and cadmium (n = 6,796) and urine cadmium (n = 2,093) levels with LTL among a nationally representative sample of US adults from the National Health and Nutrition Examination Survey (1999-2002). The study population geometric mean concentrations were 1.67 µg/dL (95% confidence interval (CI): 1.63, 1.70) for blood lead, 0.44 µg/L (95% CI: 0.42, 0.47) for blood cadmium, and 0.28 µg/L (95% CI: 0.27, 0.30) for urine cadmium. After adjustment for potential confounders, the highest (versus lowest) quartiles of blood and urine cadmium were associated with -5.54% (95% CI: -8.70, -2.37) and -4.50% (95% CI: -8.79, -0.20) shorter LTLs, respectively, with evidence of dose-response relationship (P for trend < 0.05). There was no association between blood lead concentration and LTL. These findings provide further evidence of physiological impacts of cadmium at environmental levels and might provide insight into biological pathways underlying cadmium toxicity and chronic disease risks.

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.