Effects of Cadmium, Lead, and Mercury on the Structure and Function of Reproductive Organs

Unveiling microplastic and metal pollution in giant armadillos (Priodontes maximus) from areas impacted by human activities in the Rio Doce Basin, Brazil

The giant armadillo (Priodontes maximus) is the largest armadillo species, inhabiting vast areas of South America, including forests, savannas, and grasslands. The Rio Doce State Park (RDSP) is an important conservation unit that harbors P. maximus individuals. The largest environmental disaster in Brazil occurred in 2015 when a dam collapse released tons of iron ore tailings into the Rio Doce basin. In addition to this tragedy, plastic pollution is a growing concern for the conservation of this area and raises an alert for microplastic pollution. In the present study, we investigated the presence of microplastics and heavy metals (Al, Cd, Fe, Pb, Cr, Cu, Ni, Mn, Ti, and Zn) in the feces of the giant armadillo from Rio Doce State Park to understand the invisible threats to which this species is susceptible in two areas (North and South) of RDSP. All feces samples were positive for the tested heavy metals and microplastics. Cr, Mn, and Pb levels were significantly higher in the North area, while microplastics were more abundant in the South area. The most common microplastic types identified were polypropylene (PP, 32.5 %), polyethylene terephthalate (PET, 22.5 %), and polyethylene (PE, 15.0 %). Several studies have reported the harmful effects of heavy metals and microplastics on mammals. The simultaneous presence of both contaminants highlights significant concerns for conserving this species and underscores the need for greater attention to the human impacts on RDSP's biota. This study represents an initial approach seeking to understand the exposure levels of a threatened mammal species to two relevant pollutants allowing it to offer support for new strategies for mammal conservation.

10-Hydroxy Decanoic Acid and Zinc Oxide Nanoparticles Retrieve Nrf2/HO-1 and Caspase-3/Bax/Bcl-2 Signaling in Lead-Induced Testicular Toxicity

There has been a significant increase in human exposure to heavy metals (HMs) over the course of the previous century, primarily due to the extensive industrial processes. Male infertility is a prominent complication associated with lead exposure, wherein lead has the potential to accumulate within the testes, resulting in oxidative stress and inflammation. In addition, 10-hydroxydecanoic acid (10-HDA) is a component found in the secretions of worker bees and possesses the capacity to mitigate oxidative stress and prevent inflammation. Due to their advantageous properties, zinc oxide nanoparticles (ZnO-NPs) possess a wide range of applications in the field of biomedicine. This study aimed to assess the therapeutic effect of 10-HDA and ZnO-NPs on testicular toxicity in rats induced by lead acetate (PbAc). PbAc was administered orally for a period of 3 months. Following that, 10-HDA and/or ZnO-NPs were administrated for 1 month. PbAc deformed seminal analysis, decreased seminal fructose and sex hormonal levels, and resulted in the development of histopathological complications. Additionally, PbAc increased MDA and decreased Nrf2 and HO-1 expression, confirmed by the declined antioxidant defense system. Furthermore, an increase in testicular inflammatory markers and the Bax/Bcl-2 ratio was observed subsequent to the administration of PbAc. The administration of 10-HDA and ZnO-NPs demonstrated significant efficacy in the restoration of semen quality, pituitary/gonadal hormones, antioxidants, and  testicular histoarchitecture. Moreover, 10-HDA and ZnO-NPs decreased testicular inflammatory markers and apoptotic proteins (caspase-3 and Bax expression levels). In conclusion, combining 10-HDA and ZnO-NPs demonstrated synergistic potential in treating PbAc-induced testicular toxicity, thereby presenting a promising approach in nanomedicine and natural drugs.

Alpha-Lipoic Acid Alleviates Lead-Induced Testicular Damage in Roosters by Reducing Oxidative Stress and Modulating Key Pathways

(1) Background: This study aimed to detect whether alpha-lipoic acid (ALA) supplementation could reduce lead (Pb)-induced testicular toxicity in roosters. (2) Methods: A total of 48 roosters, aged 20 weeks, were selected and randomly allocated to six treatment groups: basic diet (CON); CON + 150 mg/kg (CH3OO)2Pb (LPB); CON + 300 mg/kg (CH3OO)2Pb (HPB); CON + 300 mg/kg ALA (ALA); LPB + 300 mg/kg ALA (ALP); and HPB + 300 mg/kg ALA (AHP). (3) Results: The testicular Pb content was obviously higher in the LPB and HPB groups than in the CON group, while ALA supplementation reduced the testicular Pb content (p < 0.05). Roosters showed a significant increase in serum testosterone, sperm viability, sperm concentration, and testicular score in the AHP group compared with the HPB group. Pb exposure caused a remarkable increase in sperm abnormality and testicular malondialdehyde level, which were down-regulated by ALA supplementation (p < 0.05). RNA sequencing identified 227 differentially expressed genes (DEGs) between the HPB and CON groups and 220 DEGs between the HPB and AHP groups. (4) Conclusions: ALA supplementation mitigated Pb-induced testicular damage, suggesting its potential as a therapeutic agent for Pb toxicity in birds and potentially other species.

Assessment of Oxidative Stress and Associated Biomarkers in Wild Avian Species

Reactive oxygen species (ROS) are natural by-products of cellular metabolism and are also formed in response to environmental stressors such as pollution, extreme temperatures, and ultraviolet radiation exposure. Physiological factors such as intense activity, growth, reproduction, nutrient deficiency, captivity, and disease also contribute to ROS production. While ROS, including free radicals, play a key role in cell physiology, including immune defense, their excessive accumulation can damage cellular components and cause oxidative stress when antioxidant defenses are overwhelmed. To regulate ROS levels, wild birds rely on enzymatic (e.g., catalase, superoxide dismutase, glutathione peroxidase) and non-enzymatic antioxidants (e.g., vitamins C and E, carotenoids). Oxidative stress affects important aspects of wild bird biology, including health, reproduction, and survival, and is closely linked to overall fitness. It is also linked to physiological challenges such as migration and the progression of various diseases affecting wild bird populations. The study of oxidative stress in wild birds requires the use of appropriate biomarkers to assess its role in disease development. A deeper understanding of the balance between ROS production and antioxidant defenses is essential to determine how wild birds cope with environmental and physiological challenges. In this review, we summarize the mechanisms of oxidative stress in wild birds and the role of antioxidants in maintaining health and promoting longevity in wild bird populations.

Content of Biogenic Elements in Sheep Wool by the Regions of Slovakia

The quality of nutrition and environmental pollution are crucial chemical indicators influencing animal health, reflected in element concentrations in animal tissues and coats. This study investigates the concentrations of biogenic elements (calcium, potassium, magnesium, sodium, copper, and iron) in sheep wool from various regions of Slovakia to compare concentrations and identify possible correlations between individual elements. Samples were collected from six different regions, and concentrations of elements were measured using flame atomic absorption spectrometry. Statistical analysis revealed significant differences in element levels among the examined regions. Calcium concentrations ranged from 729.2 to 4065 ppm, with the highest concentrations in the Kysuce region and the lowest in the Šariš region. Potassium concentrations ranged from 2315 to 3282 ppm, with the lowest values in the Zemplín region and the highest in the Liptov region. Magnesium, sodium, copper, and iron also exhibited varying concentrations across the regions. Correlation analysis identified significant associations between several elements. The findings suggest that regional environmental differences influence element concentrations in sheep wool, highlighting the importance of monitoring biogenic elements for assessing environmental pollution and animal health. Further research is warranted to explore the underlying mechanisms driving element accumulation in wool and its implications for animal welfare and environmental management.

Concentrations of arsenic (As), cadmium (Cd) and lead (Pb) in blood, hair and semen of stallions in Finland

Heavy metal contamination poses significant environmental and health risks to both humans and animals. This study investigates the concentrations of arsenic (As), cadmium (Cd), and lead (Pb) in blood, hair, and semen samples collected from 16 breeding stallions in Western Finland to assess whether concentrations in hair and serum samples represent concentrations in semen. The analysis was conducted using an inductively coupled plasma mass spectrometry (ICP-MS) system. Results showed that hair samples exhibited the highest concentrations of heavy metals, particularly Pb and As, while semen showed the lowest levels. No significant correlations were found between the concentrations of heavy metals in blood and semen, or between hair and semen, indicating that blood and hair may not reliably predict metal content in semen. This study is the first to compare Pb, As, and Cd levels in hair, blood, and semen of Finnish stallions and highlights hair as a promising non-invasive biomarker of heavy metal exposure. The results underline hair's potential as a reliable long-term biomarker due to its ability to accumulate metals over time.

Fucoxanthin mitigates mercury-induced mitochondrial toxicity in the human ovarian granulosa cell line

Mercury (Hg) is known to be a hazardous toxin with a significant negative impact on female reproduction through mechanisms that remain unclear. The carotenoid fucoxanthin (FX) is an antioxidant with several positive effects on human health. This study aimed to examine the potential protective role of FX in reducing the Hg-induced bioenergetic disturbances in a human ovarian granulosa cell line model. (methods briefly) Hg was found to reduce the viability of granulosa cells in a concentration-dependent manner, with an estimated 72-hour EC50 of 10 µM. In contrast, FX (10 and 20 µM) improved cell viability. Hg (1 and 10 µM) significantly reduced cellular ATP levels, mitochondrial membrane potential, oxygen consumption rates, and lactate production. Additionally, Hg impaired the activities and kinetics of mitochondrial complexes I and III and reduced the expression of mitochondrial genes ND1, ND5, cytochrome B, cytochrome C oxidase, and ATP synthase subunits 6 and 8. According to tests on mitochondrial membranes, Hg increased membrane fluidity by reducing saturated fatty acid levels and increasing those of unsaturated fatty acids. Hg also promoted mitochondrial swelling and enhanced the inner mitochondrial membrane permeability to hydrogen and potassium ions. FX (10 µM) was shown to mitigate the negative effects of Hg on the viability of treated granulosa cells, bioenergetics parameters, and mitochondrial membrane integrity in a concentration-dependent manner. Based on these findings, bioenergetic disruption may be a key underlying cause of Hg-induced ovarian dysfunction. Furthermore, FX may have a potential therapeutic role in treating ovarian disorders caused by Hg-induced disruption of granulosa cell bioenergetics.

Determination of Electrolytes and Trace Elements in Biological Samples from Patients with Altered Semen Parameters: a Correlational Analysis

The effects of important nutrients such as calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), selenium (Se), and zinc (Zn) have been investigated in relation to male fertility due to their roles in proper spermatogenesis, sperm maturation, motility, and optimal sperm function. An imbalance between these elements has been associated with several pathologic conditions and male reproductive issues. The purpose of this study was to determine the essential trace and electrolytes elements, such as Ca, Cu, Fe, Mg, Se, and Zn, in human biological samples (blood, serum, and semen) from patients with male infertility. This study used correlational analysis to determine the potential associations between these elements and male fertility. Imbalances in these elements have been linked to various pathological conditions and male reproductive issues. One hundred eighty referent male adults and two hundred twenty-nine patients diagnosed with subtypes of infertility were included in the study, divided into two age groups. Acid digestion was controlled using a microwave oven, and the essential trace elements and electrolytes in the oxidized biological samples were determined using atomic absorption spectrometry. Certified reference materials of blood and serum were used to validate the accuracy of the methodology. The results showed that the concentrations of Ca, Cu, Fe, Mg, Se, and Zn in the blood, serum, and seminal plasma of male adults in all age groups were higher than those in patients with different infertility phenotypes. Essential element deficiency in all biological fluid samples may significantly negatively affect human reproductive health and lead to male infertility. Through a multidimensional approach, our study sought to unravel the intricate biochemical signatures associated with OAT, providing insights that may shape the landscape of diagnostic and therapeutic strategies for male reproductive health.

Exploring the impact of environmental factors on male reproductive health through epigenetics

Male infertility has become an increasingly severe global health issue, with its incidence significantly rising over the past few decades. This paper delves into the crucial role of epigenetics in male reproductive health, focusing particularly on the effects of DNA methylation, histone modifications, chromatin remodeling and non-coding RNAs regulation on spermatogenesis. Exposure to various environmental factors can cause sperm DNA damage, leading to epigenetic abnormalities. Among these factors, we have discussed heavy metals (including Zinc, Cadmium, Arsenic, Copper), phthalates, electromagnetic radiation, and temperature in detail. Notably, aberrations in DNA methylation are closely associated with various symptoms of male infertility, and histone modifications and chromatin remodeling are essential for sperm maturation and function. By synthesizing existing literature and experimental data, this narrative review investigates how environmental factors influence male reproductive health through epigenetic mechanisms, thus providing new theoretical foundations and practical guidelines for the early diagnosis and treatment of male infertility.

Using transcriptomics data and Adverse Outcome Pathway networks to explore endocrine disrupting properties of Cadmium and PCB-126

Omics-technologies such as transcriptomics offer valuable insights into toxicity mechanisms. However, integrating this type of data into regulatory frameworks remains challenging due to uncertainties regarding toxicological relevance and links to adverse outcomes. Furthermore, current assessments of endocrine disruptors (EDs) relevant to human health require substantial amounts of data, and primarily rely on standardized animal studies. Identifying EDs is a high priority in the EU, but so are efforts to replace and reduce animal testing. Alternative methods to investigate EDs are needed, and so are health risk assessment methods that support uptake of novel mechanistic information. This study aims to utilize Adverse Outcome Pathways (AOPs) to integrate transcriptomics data for identifying EDs, by establishing a link between molecular data and adverse outcomes. Cadmium (Cd) and 3,3',4,4',5-pentachlorobiphenyl (PCB126) were used as model compounds due to their observed effects on the endocrine system. An AOP network for the estrogen, androgen, thyroid, and steroidogenesis (EATS)-modalities was constructed. RNA sequencing (RNA-Seq) was conducted on zebrafish (Danio rerio) embryos exposed to Cd or PCB126 for 4 days. RNA-Seq data were then linked to the AOP network via Gene Ontology (GO) terms. Enrichment Maps in Cytoscape and the QIAGEN Ingenuity Pathway Analysis (IPA) software were also used to identify potential ED properties and to support the assessment. Potentially EATS-related GO Biological Process (BP) terms were identified for both compounds. A lack of accurate standardized terms in KEs of the AOP network hindered a data-driven mapping approach. Instead, manual mapping of GO BP terms onto the AOP network revealed more connections, underscoring the need for harmonizing AOP development for regulatory use. Both the Enrichment Maps and the IPA results further supported potentially EATS-related effects of both compounds. While AOP networks show promise in integrating RNA-Seq data, several challenges remain.

Role of epigenetic regulation in diminished ovarian reserve

Diminished ovarian reserve (DOR) is characterized by a decrease in the number and quality of oocytes, with its incidence increasing annually. Its pathogenesis remains unclear, making it one of the most challenging problems in the field of assisted reproduction. Epigenetic modification, a molecular mechanism affecting genomic activity and expression without altering the DNA sequence, has been widely studied in reproductive medicine and has attracted considerable attention regarding DOR. This review comprehensively examines the various epigenetic regulatory changes in ovarian granulosa cells (OGCs) and oocytes during DOR. DNA methylation plays a crucial role in regulating granulosa cell function, hormone production, and oocyte development, maturation, and senescence. Histone modifications are involved in regulating follicular activation, while non-coding RNAs, such as long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), regulate granulosa cell function and oocyte development. N6-methyladenosine (m6A) modifications are associated with age-related oocyte senescence. Epigenetic clocks based on DNA methylation show potential in predicting ovarian reserve in DOR. Furthermore, it discusses the potential for utilizing epigenetic mechanisms to better diagnose and manage DOR.

HBM4EU E-waste study - An untargeted metabolomics approach to characterize metabolic changes during E-waste recycling

E-waste contains hazardous chemicals that may be a direct health risk for workers involved in recycling. We conducted an untargeted metabolomics analysis of urine samples collected from male e-waste processing workers to explore metabolic changes associated with chemical exposures in e-waste recycling in Belgium, Finland, Latvia, Luxembourg, the Netherlands, Poland, and Portugal. Questionnaire data and urine samples were obtained from workers involved in the processing of e-waste (sorting, dismantling, shredding, pre-processing, metal, and non-metal processing), as well as from controls with no known occupational exposure. Pre- and post-shift urine samples were collected and analysed using ultrahigh-performance liquid chromatography-mass spectrometry (UPLC-MS). A total of 32 endogenous urinary metabolites were annotated with a Variable Importance in Projection (VIP) above 2, indicating that e-waste recycling is mainly associated with changes in steroid hormone and neurotransmitter metabolism, energy metabolism, bile acid biosynthesis, and inflammation. The highest VIP was observed for dopamine-o-quinone, which is linked to Parkinson's disease. These and other changes in metabolism in workers employed in the processing of e-waste need further verification in targeted studies.

Detrimental effects of cadmium on male infertility: A review

Infertility has become a serious health and socio-economic-psychological problem globally. The harmful role of trace metals in male infertility is recognized but still not sufficiently explained. Herein, a comprehensive review was conducted to elucidate the detrimental role of cadmium (Cd) on male infertility, particularly on infertility with unknown (idiopathic) causes. Peer-reviewed studies from 2000 to 2024 dealing with seminal plasma and blood Cd levels of fertile and infertile men were retrieved were interrogated with regard to strict inclusion/exclusion criteria, and then were thoroughly reviewed and analyzed. Another aim of this review was to indicate the potential effects of Cd on changes in seminogram findings. A median range of seminal plasma Cd levels from 0.2 to 1.5 µg/L can be considered safe for men's fertility. This review strongly implies that Cd levels were notably higher in seminal plasma of infertile cases than controls. The review's data also indicate that exposure to tobacco smoke is a major source of elevated seminal and blood Cd levels in infertile men. Newer research points to the importance of Cd in lower levels from the environment on changes in seminogram findings, primarily count, motility of spermatozoa, and their morphology. Overall, this review implies that seminal plasma Cd levels could be a good indicator of semen quality. However, new, in-depth studies are needed to confirm or reject the causal relationship of Cd with male infertility.

Associations of Essential and Non-Essential Trace Elements' Levels in the Blood, Serum, and Urine in Women with Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is poorly understood, with causes identified in only 25% of cases. Emerging evidence suggests links between trace elements (TEs) and POI. This study is the first to compare concentrations of manganese (Mn), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) across urine, serum, and whole blood in women with POI compared to healthy controls (HC), aiming to explore their distribution and potential associations with POI. This cross-sectional-case-control study enrolled 81 participants (40 POI patients and 41 healthy controls) at the University Medical Centre Ljubljana, Slovenia. Blood and urine samples were collected to quantify basic biochemical parameters using standard clinical chemistry methods and concentrations of Mn, Cu, Zn, Se, Mo, As, Cd, Hg, and Pb using inductively coupled plasma-mass spectrometry (ICP-MS). Participants also completed questionnaires on socio-demographics, medical history, lifestyle, and nutrition. Data was analyzed using the Mann-Whitney U test, Student's t-tests, Fisher exact test, logistic regression models adjusted on body mass index (BMI), age, hematocrit, and Kendall's tau correlation. Women with POI had significantly higher BMI and red blood cell (RBC) indices, including hemoglobin, hematocrit, and red cell distribution width (RDW), compared to controls. A larger proportion of POI patients resided in rural agricultural areas. Liver and kidney function assessments showed no significant differences between the groups. Adjusted models revealed that POI patients had significantly lower urinary levels of Cu, Zn, Se, Mo, Cd, Hg, and Pb than controls, while whole blood Mn levels were higher. Serum Cu levels were significantly elevated in POI patients, whereas Pb, Cd, and Hg were lower. No significant differences were observed for As. Correlation analysis showed several strong to moderate associations among TEs across biofluids, but only weak correlations were found between TEs and demographic or biochemical factors. This study suggests potential associations between TEs and POI in women. Notably, most TEs (Zn, Se, Cu, Mo, Cd, Hg, Pb) were significantly lower in the urine of the POI group, while Cu, Cd, Hg, and Pb showed significant differences in both urine and serum.

Nanostructured biloalbuminosomes loaded with berberine and berberrubine for Alleviating heavy Metal-Induced male infertility in rats

Despite the remarkable biological effects of berberine (BBR), particularly on fertility, its bioavailability is low. This study aims to test the effectiveness of novel nanostructured biloalbuminosomes (BILS) of BBR and its metabolite berberrubine (M1) in treatment of testicular and prostatic lesions. M1 was semi-synthesized from BBR using microwave-assisted reaction. The solvent evaporation method was used to prepare BBR-BILS and M1-BILS by three different concentrations of sodium cholate (SC) or glycocholate (SG), along with the incorporation of bovine serum albumin (BSA). The prepared BILS were fully characterized. Male infertility was induced by cadmium (Cd) at 5 mg/kg and lead (Pb) at 20 mg/kg contaminated water for 90 days, followed by treatment with BBR, M1, and their BILS (BBR-BILS and M1-BILS) for 45 days. Blood male infertility markers, testicular and prostatic oxidative stress status, autophagy, inflammation, along with testicular and prostatic concentrations of Cd and Pb, and histopathology of both tested tissues were determined using standardized protocols. The optimal BBR-BILS and M1-BILS nano-preparations, containing 30 mg SC, were chosen based on the best characterization properties of the preparations. Both nano-preparations improved heavy metals-induced testicular and prostatic deformities, as they reduced Bax and elevated Bcl-2 expressions in both tissues. Moreover, they activated the mTOR/PI3K pathway with a marked reduction in AMPK and activated LC-3II protein levels. Consequently, testicular and prostatic architecture and functions were improved. This study is the first to report the preparation of BBR and M1 BILS nano-preparations and proved their superior efficacy compared to free drugs against testicular and prostatic deformities by attenuating oxidative stress-induced excessive autophagy, offering a new hope to manage male infertility.

Epigenetic Mechanisms of Endocrine-Disrupting Chemicals in Breast Cancer and Their Impact on Dietary Intake

Addressing the consequences of exposure to endocrine-disrupting chemicals (EDCs) demands thorough research and elucidation of the mechanism by which EDCs negatively impact women and lead to breast cancer (BC). Endocrine disruptors can affect major pathways through various means, including histone modifications, the erroneous expression of microRNA (miRNA), DNA methylation, and epigenetic modifications. However, it is still uncertain if the epigenetic modifications triggered by EDCs can help predict negative outcomes. Consequently, it is important to understand how different endocrine disrupters or signals interact with epigenetic modifications and regulate signalling mechanisms. This study proposes that the epigenome may be negatively impacted by several EDCs, such as cadmium, arsenic, lead, bisphenol A, phthalates, polychlorinated biphenyls and parabens, organochlorine, and dioxins. Further, this study also examines the impact of EDCs on lifestyle variables. In breast cancer research, it is essential to consider the potential impacts of EDC exposure and comprehend how EDCs function in tissues.

Acute and sub-acute toxicity study of aqueous and methanol root extract of Tetracera alnifolia in male albino rats

The aim of this study was to assess the acute and sub-acute toxicity of aqueous and methanol extracts of the root of Tetracera alnifolia as well as the effects on some biochemical parameters in albino rats as many plants used in traditional medicine lack scientific and clinical evidence to support a better understanding of their safety and efficacy. Phytochemical screening and proximate analysis of the pulverised root of Tetracera alnifolia was carried out using previously reported protocol. Sub-acute toxicity study of each extract was done for 28 days followed by organs function tests and histopathology studies of the liver, kidney and heart. Evaluation of lipid profile and oxidative stress marker to ascertain the effect of each extract on lipid peroxidation and their antioxidant property was done after administration of 200 mg/Kg body weight of each extract for a period of thirty-five days. Acute toxicity study of each extract gave oral LD50 (rat) of greater than 5000 mg/kg body weight with no signs of toxicity. Sub-acute toxicity study showed both extracts were non-toxic to the liver, kidney, heart and blood at doses between 200 and 3000 mg/Kg body weight assessed by the respective organ function tests, hematological parameters, and histopathology study. However, higher doses seem toxic to the liver particularly at 5000 mg/kg B. W due to increase in plasma AST, ALT and ALP activities accompanied with reduced protein and albumin concentrations. Effects of each extracts at 200 mg/Kg body weight on some biochemical parameters revealed no significant difference in lipid profile parameters and no lipid peroxidation. Each extract may possess antioxidant property due to increase in catalase activity. The result from this research may help validate the safety of the oral use of this plant in traditional medicine.

The Mechanisms of Cadmium Toxicity in Living Organisms

Cadmium (Cd) is a toxic metal primarily found as a by-product of zinc production. Cd was a proven carcinogen, and exposure to this metal has been linked to various adverse health effects, which were first reported in the mid-19th century and thoroughly investigated by the 20th century. The toxicokinetics and dynamics of Cd reveal its propensity for long biological retention and predominant storage in soft tissues. Until the 1950s, Cd pollution was caused by industrial activities, whereas nowadays, the main source is phosphate fertilizers, which strongly contaminate soil and water and affect human health and ecosystems. Cd enters the human body mainly through ingestion and inhalation, with food and tobacco smoke being the primary sources. It accumulates in various organs, particularly the kidney and liver, and is known to cause severe health problems, including renal dysfunction, bone diseases, cardiovascular problems, and many others. On a cellular level, Cd disrupts numerous biological processes, inducing oxidative stress generation and DNA damage. This comprehensive review explores Cd pollution, accumulation, distribution, and biological impacts on bacteria, fungi, edible mushrooms, plants, animals, and humans on a molecular level. Molecular aspects of carcinogenesis, apoptosis, autophagy, specific gene expression, stress protein synthesis, and ROS formation caused by Cd were discussed as well. This paper also summarizes how Cd is removed from contaminated environments and the human body.

Selenized Yeast Protects Against Cadmium-Induced Follicular Atresia in Laying Hens by Reducing Autophagy in Granulosa Cells

Cadmium (Cd) exposure can induce follicular atresia and laying performance reduction in hens, which is linked to autophagy within the granulosa cells. Selenium (Se) can influence autophagy and counteract Cd toxicity. This study aimed to investigate the protective effect of Se on Cd-induced follicular atresia in laying hens. Sixty-four laying hens were randomly allocated into 4 treatments: control group: basal diet; Se group: basal diet + 0.4 mg/kg Se from selenized yeast; Cd group: basal diet + 25 mg/kg Cd from CdCl2; and Cd+Se group: basal diet + 25 mg/kg Cd + 0.4 mg/kg Se. Compared to the Cd group, Se supplementation alleviated the ovarian pathological changes and oxidative stress in the follicles, serum, liver, and ovary, increased daily laying production, ovarian weight and F5-F1 follicle amounts, serum levels of progesterone and oestradiol, and up-regulated mTOR expression (p < 0.05), while decreasing the count of autophagic vacuoles, ovarian atresia follicle numbers, and Cd deposition, and down-regulated expression levels of autophagy-related mRNAs, including ATG5, LC3-I, and LC3-II, Beclin1, and Dynein in the follicles (p < 0.05). In conclusion, 0.4 mg/kg Se supplementation protected against Cd-induced laying performance reduction and follicular atresia, which were achieved via decreasing oxidative stress and inhibiting mTOR pathways of autophagy.

PFAS Exposure is Associated with a Lower Spermatic Quality in an Arctic Seabird

Several studies have reported an increasing occurrence of poly- and perfluorinated alkyl substances (PFASs) in Arctic wildlife tissues, raising concerns due to their resistance to degradation. While some research has explored PFAS's physiological effects on birds, their impact on reproductive functions, particularly sperm quality, remains underexplored. This study aims to assess (1) potential association between PFAS concentrations in blood and sperm quality in black-legged kittiwakes (Rissa tridactyla), focusing on the percentage of abnormal spermatozoa, sperm velocity, percentage of sperm motility, and morphology; and (2) examine the association of plasma levels of testosterone, corticosterone, and luteinizing hormone with both PFAS concentrations and sperm quality parameters to assess possible endocrine disrupting pathways. Our findings reveal a positive correlation between the concentration of longer-chain perfluoroalkyl carboxylates (PFCA; C11-C14) in blood and the percentage of abnormal sperm in kittiwakes. Additionally, we observed that two other PFAS (i.e., PFOSlin and PFNA), distinct from those associated with sperm abnormalities, were positively correlated with the stress hormone corticosterone. These findings emphasize the potentially harmful substance-specific effects of long-chain PFCAs on seabirds and the need for further research into the impact of pollutants on sperm quality as a potential additional detrimental effect on birds.

Leek (Allium ampeloprasum var. kurrat) aqueous extract loaded on selenium nanoparticles protects against testis and brain injury induced by mercuric chloride in rats

BACKGROUND

Mercuric chloride (HgCl2) is poisonous to humans and animals and typically damages the nervous system and other organs. Mercuric chloride exposition disclosed to initiation of oxidative stress pathway can result in a defect in male fertility and testis tissue. Synthesized selenium nanoparticles (SeNPs) were characterized with a diameter range minimal than 100 nm, having the effective sets of the biological matter. The present study aimed to evaluate the effect of biosynthesized SeNPs, prepared by leek extract on Wistar rats' testicles and brain.

METHODS

Thirty-five Wistar male rats (120-150 g) were randomly split into five groups (n = 7), orally ingested with leek aqueous extract loaded on SeNPs, and then the animals were administered with mercury II chloride (HgCl2) to induce testis injury and damage the nervous system.

RESULTS

The used dose of mercuric chloride led to oxidative stress damage in the testis of the rats which was evidenced by a decrease in testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and proliferating cell nuclear antigen (PCNA) levels, and an increase in nuclear factor-kappa B (NF-κB) and caspase-3. Also, HgCl2 decreased the levels of dopamine (DA), serotonin (5-HT), norepinephrine (NE) and brain-derived neurotrophic factor (BDNF) in the brains of rats. In addition, A decrease was observed in the levels of antioxidant markers, B-cell lymphoma-2 (Bcl-2), as well as an increase in malondialdehyde (MDA), nitric oxide (NO), NF-κB, tumor necrosis factor (TNF)-α, interleukin (IL)-1β and Bax in both testes and brains. Pre-treatment with leek extract loaded on SeNPs significantly ameliorated testosterone, LH, FSH, PCNA and caspase-3 levels in the testis and DA, 5-HT, NE and BDNF in brains. Although the contents of MDA, NO, TNF-α, IL-1β, NF-κB and Bax decreased significantly in both. glutathione, glutathione peroxidase, glutathione reductase, catalase, superoxide dismutase and Bcl-2 levels were significantly improved in both organs.

CONCLUSION

Our findings suggest that treatment with aqueous leek extract loaded on SeNPs may offer promising prospects for the advancement of anti-inflammation activity against testis injury and also have a very key role in neurobehavioral alterations as a result of mercury toxicity. © 2024 Society of Chemical Industry.

Protective effects of resveratrol on the expression of catalase, glutathione peroxidase, and superoxide dismutase genes in the ovary and their activity in the serum of rats exposed to lead acetate: An experimental study

Background

Lead (Pb) could be toxic to the female reproductive system, and resveratrol (Res) may overcome this toxicity.

Objective

To investigate the Res impact on the catalase (Cat), glutathione peroxidase (Gpx), and superoxide dismutase (Sod) gene expression in the ovary and on the Cat and Gpx enzyme activity in the serum of rats exposed to lead acetate.

Materials and Methods

In this experimental study, 33 female Wistar rats (8-10 wk, 180-200 gr) were divided into 6 groups: a control group (normal saline), a Res group (40 mg/kg), and a Pb group (lead acetate 30 mg/kg). 3 additional groups received lead acetate (30 mg/kg) with Res at 20, 40, and 80 mg/kg for 21 days. Gene expression of Cat, Gpx, and Sod was measured via qPCR, and serum Cat and Gpx activity was assessed using standard methods. Bioinformatics tools were used to evaluate Res effects on gene and protein function.

Results

Lead acetate significantly downregulates Cat, Gpx, and Sod gene expression, but Res significantly upregulates gene expression, especially at doses of 40 mg/kg for Cat, 20 mg/kg and 40 mg/kg for Gpx, and 80 mg/kg for Sod. Cat and Gpx enzyme activity increased and decreased in the lead acetate group, respectively. However, Res in all doses decreased only the Cat enzyme activity. Bioinformatics analysis indicates that Res can interact with the promoter regions and cavities of all 3 enzymes.

Conclusion

Pb can dysregulate the expression and activity of the studied enzymes. However, the impact of Res is influenced by the dose, with 40 mg/kg frequently being the most effective.

Heavy Metals and Trajectories of Anti-Müllerian Hormone During the Menopausal Transition

BACKGROUND

Experimental and epidemiological studies have linked metals with women's reproductive aging, but the mechanisms are not well understood. Disrupted ovarian folliculogenesis and diminished ovarian reserve could be a pathway through which metals impact reproductive hormones and outcomes.

OBJECTIVE

The study aimed to evaluate the associations of heavy metals with anti-Müllerian hormone (AMH), a marker of ovarian reserve.

METHODS

The study included 549 women from the Study of Women's Health Across the Nation with 2252 repeated AMH measurements from 10 to 0 years before the final menstrual period (FMP). Serum AMH concentrations were measured using picoAMH ELISA. Urinary concentrations of arsenic, cadmium, mercury, and lead were measured using high-resolution inductively coupled plasma mass spectrometry. Multivariable linear mixed regressions modeled AMH as a function of time before the FMP interaction terms between metals and time to the FMP were also included.

RESULTS

Adjusting for confounders, compared with those in the lowest tertile, women in the highest tertile of urinary arsenic or mercury concentrations had lower AMH concentrations at the FMP (percent change: -32.1%; 95% CI, -52.9 to -2.2, P-trend = .03 for arsenic; percent change: -40.7%; 95% CI, -58.9 to -14.5, P-trend = .005 for mercury). Higher cadmium and mercury were also associated with accelerated rates of decline in AMH over time (percent change per year: -9.0%; 95% CI, -15.5 to -1.9, P-trend = .01 for cadmium; -7.3%; 95% CI, -14.0 to -0.1, P-trend = .04 for mercury).

CONCLUSION

Heavy metals including arsenic, cadmium, and mercury may act as ovarian toxicants by diminishing ovarian reserve in women approaching the FMP.

Analysis of Differential Gene Expression under Acute Lead or Mercury Exposure in Larval Zebrafish Using RNA-Seq

This study was first conducted to investigate the effects of acute lead exposure on developing zebrafish embryos or larvae from 24 to 120 h post-fertilization (hpf). Our data showed that treatment with 50-200 μM lead significantly affected larval survivability and morphology compared to the respective control. Second, we chose 120 hpf larvae treated with 12.5 μM lead for RNA sequencing due to its exposure level being sufficient to produce toxic effects with minimum death and lead bioaccumulation in developing zebrafish. A total of 137.45 million raw reads were obtained, and more than 86% of clean data were mapped to the zebrafish reference genome. Differential expression profiles generated 116 up- and 34 down-regulated genes upon lead exposure. The most enriched GO terms for representative DEGs were ion transport and lipid metabolism. Third, a comparison with the dataset of mercury-regulated gene expression identified 94 genes (64 up-regulated and 30 down-regulated) for exposure specific to lead, as well as 422 genes (338 up-regulated and 84 down-regulated) for exposure specific to mercury. In addition, 56 genes were co-regulated by micromolar mercury and lead treatment, and the expression of thirteen genes, including mt2, ctssb.1, prdx1, txn, sqrdl, tmprss13a, socs3a, trpv6, abcb6a, gsr, hbz, fads2, and zgc:92590 were validated by qRT-PCR. These genes were mainly associated with metal ion binding, proteolysis, antioxidant activity, signal transduction, calcium ion or oxygen transport, the fatty acid biosynthetic process, and protein metabolism. Taken together, these findings help better understand the genome-wide responses of developing zebrafish to lead or mercury and provide potential biomarkers for acute exposure to toxic metals.

Natural mercury exposure of European insectivorous bats may exceed a recognized toxicity threshold

Heavy metals are an important group of toxic substances harmful for many organisms. Of these, mercury is one of the most monitored in the environment. Several matrices are used for the monitoring of environmental load, including a range of organisms; bats, however, have only been examined rarely. Insectivorous bats are apex predators threatened by several human interventions in their natural environment, including heavy metal pollution. The aim of this study was to analyze the content of total mercury in the fur, flight membrane, and pectoral muscle of greater mouse-eared bats (Myotis myotis). Total mercury concentrations were also measured in carabid beetles from the catch locality Zastávka u Brna. Samples were obtained from 43 bat carcasses at two different localities in the Czech Republic (Zastávka u Brna, Malá Morávka). Total mercury content varied between 1.76-72.20 µg/g in fur, 0.04-0.14 µg/g in skin, and 0.05-0.20 µg/g in muscle. Total mercury values in the fur of some individuals from Malá Morávka exceeded the recognized toxicity limit. Furthermore, there was a significant difference (p < 0.001) in content of total mercury in fur between localities, and there was a clear effect of age on concentrations in fur, skin, and muscle, the concentrations being significantly correlated (fur and skin rs = 0.783; fur and muscle rs = 0.716; skin and muscle rs = 0.884). These findings confirm the usefulness of fur samples from living bats for biomonitoring mercury burden in the environment.

Quantitative analysis and health risk assessment of selected heavy metals in pet food samples using ultrasound assisted hydrogen peroxide extraction followed by ICP-OES analysis

There is a lack of information regarding the presence of heavy metals in feed ingredients for animals. Therefore, this study examines 10 feed samples collected from commercial pet food in South African market. The optimal working parameters for ultrasound assisted hydrogen peroxide extraction (UA-HPE) confirmed by multivariate optimization were sonication temperature at 80 °C for 60 min, sample mass of 0.1 g, and H2O2 concentration of 5 mol/L. The UA-HPE results demonstrated high accuracy of (>95%), reproducibility (≤1.9%), low method of detection limits (0.3498 and 0.49 μg/g), and strong linearity as confirmed by regression analysis. The environmental friendliness of the UA-HPE method was assessed using AGREEPrep metric tool that resulted with a score of 0.74. The concentration levels of Cd, Pb and As, ranged between 0.86 and 11.34, 4.50-11.45, and 2.61-12.5 μg/g, respectively greater than the standardized limits, whilst Cr, and Sn were below the limits of detection in all pet food. The health index calculations (HI > 1) revealed that the cat, dog, and horse feed pose health risk for animal consumption. Consequently, this study demonstrated a green, efficient, and cost-effective method for the analysis of animal feed with high accuracy.

Protective Effects of Syringic Acid Against Oxidative Damage, Apoptosis, Autophagy, Inflammation, Testicular Histopathologic Disorders, and Impaired Sperm Quality in the Testicular Tissue of Rats Induced by Mercuric Chloride

Mercury (Hg) is one of the most toxic heavy metals that damage testicular tissue. Mercury chloride (HgCl2) is one of the most toxic forms of mercury that can easily cross biological membranes. Syringic acid (SA) is a natural flavonoid found in many vegetables and fruits. In this study, the effects of SA against HgCl2-induced testicular damage in rats were determined by biochemical, histopathological, and spermatological analyses. For this study, a total of 35 Spraque Dawley rats were used. Rats were divided into five groups as control, HgCl2, SA 50, HgCl2 + SA 25, and HgCl2 + SA 50. HgCl2 was administered intraperitoneal (IP) at a dose of 1.23 mg/kg/bw, while SA was administered by oral gavage at doses of 25 and 50 mg/kg/bw. The rats were then sacrificed, and testicular tissues were removed. HgCl2 caused an increase in MDA level and a decrease in SOD, CAT, and GPx activity and GSH level in the testicular tissue of rats. HgCl2 is involved in the increase of eIF2-α, PERK, ATF-4, ATF-6, CHOP, NF-κB, TNF-α, IL-1β, Apaf-1, Bax, and Caspase-3 mRNA expression. HgCl2 caused a decrease in sperm motility, an increase in the rate of abnormal sperm and sperm DNA fragmentation in rats. However, SA oral administration dose-dependently inhibited endoplasmic reticulum stress, oxidative stress, inflammation, and apoptosis and preserved epididymal sperm quality and testicular histoarchitectures. In conclusion, SA had protective effects against HgCl2-induced testicular oxidative damage, inflammation, endoplasmic reticulum stress, and apoptosis.

Carvacrol Reduces Mercuric Chloride-Induced Testicular Toxicity by Regulating Oxidative Stress, Inflammation, Apoptosis, Autophagy, and Histopathological Changes

Mercuric chloride (HgCl2) is a heavy metal that is toxic to the human body. Carvacrol (CAR) is a flavonoid found naturally in plants and has many biological and pharmacological activities including anti-inflammatory, antioxidant, and anticancer activities. This study aimed to investigate the efficacy of CAR in HgCl2-induced testicular tissue damage. HgCl2 was administered intraperitoneally at a dose of 1.23 mg/kg body weight alone or in combination with orally administered CAR (25 mg/kg and 50 mg/kg body weight) for 7 days. Biochemical and histological methods were used to investigate oxidative stress, inflammation, apoptosis, and autophagy pathways in testicular tissue. CAR treatment increased HgCl2-induced decreased antioxidant enzyme (SOD, CAT, and GPx) activities and GSH levels. In addition, CAR reduced MDA levels, a marker of lipid peroxidation. CAR decreased the levels of inflammatory mediators NF-κB, TNF-α, IL-1β, COX-2, iNOS, MAPK14, MAPK15, and JNK. The increases in apoptotic Bax and Caspase-3 with HgCl2 exposure decreased with CAR, while the decreased antiapoptotic Bcl-2 level increased. CAR reduced HgCl2-induced autophagy damage by increasing Beclin-1, LC3A, and LC3B levels. Overall, the data from this study suggested that testicular tissue damage associated with HgCl2 toxicity can be mitigated by CAR administration.

Decoding the Epigenetics of Infertility: Mechanisms, Environmental Influences, and Therapeutic Strategies

Infertility is a complex condition caused by a combination of genetic, environmental, and lifestyle factors. Recent advances in epigenetics have highlighted the importance of epigenetic changes in fertility regulation. This review aims to provide a comprehensive overview of the epigenetic mechanisms involved in infertility, with a focus on DNA methylation, histone modification, and non-coding RNAs. We investigate the specific epigenetic events that occur during gametogenesis, with a focus on spermatogenesis and oogenesis as distinct processes. Furthermore, we investigate how environmental factors such as diet, stress, and toxin exposure can influence these epigenetic changes, potentially leading to infertility. The second part of the review explores epigenetic changes as therapeutic targets for infertility. Emerging therapies that modulate epigenetic marks present promising opportunities for fertility restoration, particularly in spermatogenesis. By summarizing current research findings, this review emphasizes the importance of understanding epigenetic contributions to infertility. Our discussion aims to lay the groundwork for future research directions and clinical applications in reproductive health.

Assessment of heavy metal and radioactive element levels in the ovarian follicular fluid of pregnant and non-pregnant Kyrgyz breed mares

Objective

In the current study, we aimed to ascertain the levels of heavy metals and radioactive elements in the ovarian follicular fluids of pregnant and non-pregnant Kyrgyz mares.

Materials and Methods

To this end, follicular fluids were obtained from 49 Kyrgyz mares aged 3-5 years. The mares were in various stages of pregnancy (Group 1, n = 27) or were non-pregnant (Group 2, n = 22). We measured the levels of cadmium (Cd), lead (Pb), mercury (Hg), antimony (Sb), cobalt (Co), potassium (K), uranium (U), nickel (Ni), and thorium (Th) in follicular fluids using atomic emission mass spectrometry. Subsequently, the data were statistically analyzed according to whether the mare was pregnant or not, the pregnancy stage, the presence or absence of the corpus luteum in the ovaries, the corpus luteum's diameter if present, and the presence or absence and diameter of follicles.

Results

We found that K levels were higher in non-pregnant mares (0.00564 ± 0.000590 ppm, p = 0.009). Furthermore, Ni (0.01033 ± 0.001880 ppm, p = 0.07) and K (0.00563 ± 0.000498 ppm, p = 0.026) levels were higher in mares with a follicle diameter of 1-3 cm. However, these results did not change according to the month of pregnancy, number of follicles, presence or absence of the corpus luteum in the ovaries, number of corpora lutea, and their diameters.

Conclusion

Thus, we concluded that heavy metal and radioactive element levels in the ovarian follicular fluids of Kyrgyz mares do not significantly change with pregnancy status, and there are limited detrimental effects of pollution on the follicular fluids.

Role of Anonychium africanum (Plantae, Fabaceae) in Metal Oxido-Inflammatory Response: Protection Evidence in Gonad of Male Albino Rat

Male fertility is strongly affected by the overexpression of free radicals induced by heavy metals. The aim of this study was to evaluate the potential antioxidant, anti-inflammatory, and gonado-protective effects of natural compounds. Biochemical and morphological assays were performed on male albino rats divided into five groups: a control group (water only), a group orally exposed to a metal mixture of Pb-Cd-Hg-As alone and three groups co-administered the metal mixture and an aqueous extract of the Nigerian medicinal plant, Anonychium africanum (Prosopis africana, PA), at three different concentrations (500, 1000, and 1500 mg/kg) for 60 days. The metal mixture induced a significant rise in testicular weight, metal bioaccumulation, oxidative stress, and pro-inflammatory and apoptotic markers, while the semen analysis indicated a lower viability and a decrease in normal sperm count, and plasma reproductive hormones showed a significant variation. Parallel phytochemical investigations showed that PA has bioactive compounds like phlobatannins, flavonoids, polyphenols, tannins, saponins, steroids, and alkaloids, which are protective against oxidative injury in neural tissues. Indeed, the presence of PA co-administered with the metal mixture mitigated the toxic metals' impact, which was determined by observing the oxido-inflammatory response via nuclear factor erythroid 2-related factor 2, thus boosting male reproductive health.

Is Copper Still Safe for Us? What Do We Know and What Are the Latest Literature Statements?

Copper (Cu) is a precious metal and one of the three most abundant trace elements in the body (50-120 mg). It is involved in a large number of cellular mechanisms and pathways and is an essential cofactor in the function of cellular enzymes. Both its excess and deficiency may be harmful for many diseases. Even small changes in Cu concentration may be associated with significant toxicity. Consequently, it can be damaging to any organ or tissue in our body, beginning with harmful effects already at the molecular level and then affecting the degradation of individual tissues/organs and the slow development of many diseases, such as those of the immunological system, skeletal system, circulatory system, nervous system, digestive system, respiratory system, reproductive system, and skin. The main purpose of this article is to review the literature with regard to both the healthiness and toxicity of copper to the human body. A secondary objective is to show its widespread use and sources, including in food and common materials in contact with humans. Its biological half-life from diet is estimated to range from 13 to 33 days. The retention or bioavailability of copper from the diet is influenced by several factors, such as age, amount and form of copper in the diet, lifestyle, and genetic background. The upper limit of normal in serum in healthy adults is approximately 1.5 mg Cu/L, while the safe upper limit of average intake is set at 10-12 mg/day, the reference limit at 0.9 mg/day, and the minimum limit at 0.6-0.7 mg/day. Cu is essential, and in the optimal dose, it provides antioxidant defense, while its deficiency reduces the body's ability to cope with oxidative stress. The development of civilization and the constant, widespread use of Cu in all electrical devices will not be stopped, but the health of people directly related to its extraction, production, or distribution can be controlled, and the inhabitants of nearby towns can be protected. It is extremely difficult to assess the effects of copper on the human body because of its ubiquity and the increasing reports in the literature about its effects, including copper nanoparticles.

Molybdenum and cadmium co-induce necroptosis through Th1/Th2 imbalance-mediated endoplasmic reticulum stress in duck ovaries

Cadmium (Cd) and excess molybdenum (Mo) pose serious threats to animal health. Our previous study has determined that Cd and/or Mo exposure can cause ovarian damage of ducks, while the specific mechanism is still obscure. To further investigate the toxic mechanism of Cd and Mo co-exposure in the ovary, forty 8-day-old female ducks were randomly allocated into four groups for 16 weeks, and the doses of Cd and Mo in basic diet per kg were as follows: control group, Mo group (100 mg Mo), Cd group (4 mg Cd), and Mo + Cd group (100 mg Mo + 4 mg Cd). Cadmium sulfate 8/3-hydrate (CdSO4·8/3H2O) and hexaammonium molybdate ((NH4)6Mo7O24·4H2O) were the origins of Cd and Mo, respectively. At the 16th week of the experiment, all ovary tissues were collected for the detection of related indexes. The data indicated that Mo and/or Cd induced trace element disorders and Th1/Th2 balance to divert toward Th1 in the ovary, which activated endoplasmic reticulum (ER) stress and then provoked necroptosis through triggering RIPK1/RIPK3/MLKL signaling pathway, and eventually caused ovarian pathological injuries and necroptosis characteristics. The alterations of above indicators were most apparent in the joint group. Above all, this research illustrates that Mo and/or Cd exposure can initiate necroptosis through Th1/Th2 imbalance-modulated ER stress in duck ovaries, and Mo and Cd combined exposure aggravates ovarian injuries. This research explores the molecular mechanism of necroptosis caused by Mo and/or Cd, which reveals that ER stress attenuation may be a therapeutic target to alleviate necroptosis.

Direct and Indirect Linkages Between Trace Element Status and Health Indicators - a Multi-tissue Case-Study of Two Deer Species in Denmark

Measuring trace element concentrations in tissue can be a valuable approach to monitor animal health status. Temporal variation in the absorption, transport, and storage of elements between different tissues can, however, complicate the assessment of element-health relationships. Here, we measured concentrations of selected essential (copper (Cu), zinc (Zn), selenium (Se)) and non-essential (arsenic (As), cadmium (Cd), lead (Pb)) trace elements within blood, liver, kidney, and hair of fallow deer (Dama dama; N=20) and red deer (Cervus elaphus; N=21). Using multivariate regression and structural equation models, we estimated direct and indirect linkages between tissue-specific trace element profiles and long- (body condition) and short-term (serum protein biomarkers for acute inflammation, infection, and malnutrition) health indicators. Trace element concentrations varied markedly and were weakly correlated among tissues, with the exception of Se. After accounting for sex- and site-differences in trace element concentrations, body condition of red deer was directly, and positively, associated to trace element status in liver and hair, but not in kidney. For both deer species, trace element status in blood was directly linked to serum protein status with an indirect positive association to deer body condition. For fallow deer, no direct association between trace element status and body condition was detected in any of the tissues, possibly because of elemental homeostasis, and because all individuals were in good clinical health. This study shows that hair can serve as an effective, non-invasive, biomarker in deer health assessments, yet, to fully uncover trace element-health relationships a variety of sample matrices is preferred.

Targeting JAK2/STAT3, NLRP3/Caspase-1, and PK2/PKR2 Pathways with Arbutin Ameliorates Lead Acetate-Induced Testicular Injury in Rats

The reproductive system of males is adversely impacted by lead (Pb), a toxic heavy metal. The present study examined arbutin, a promising hydroquinone glycoside, for its potential ameliorative impact against Pb-induced testicular impairment in rats. The testicular injury was induced by the intraperitoneal administration of Pb acetate (20 mg/kg/day) for 10 consecutive days. Thirty-six rats were divided into six experimental groups (n = 6 per group): control, control treated with oral arbutin (250 mg/kg), control treated with intraperitoneal arbutin (75 mg/kg), untreated Pb, Pb treated with oral arbutin, and Pb treated with intraperitoneal arbutin. The treatments were administered daily for 10 days. Arbutin was administered by the oral and intraperitoneal routes to compare the efficacy of both routes in mitigating Pb acetate-induced testicular dysfunction. The current data revealed that both oral and intraperitoneal administration of arbutin significantly enhanced serum testosterone and sperm count/motility, indicating the amelioration of testicular dysfunction. In tandem, both routes lowered testicular histopathological aberrations and Johnsen's damage scores. These favorable outcomes were driven by dampening testicular oxidative stress, evidenced by lowered lipid peroxidation and increased glutathione and catalase antioxidants. Moreover, arbutin lowered testicular p-JAK2 and p-STAT3 levels, confirming the inhibition of the JAK2/STAT3 pro-inflammatory pathway. In tandem, arbutin suppressed the testicular NLRP3/caspase-1/NF-B axis and augmented the cytoprotective PK2/PKR2 pathway. Notably, intraperitoneal arbutin at a lower dose prompted a more pronounced mitigation of Pb-induced testicular dysfunction compared to oral administration. In conclusion, arbutin ameliorates Pb-evoked testicular damage by stimulating testicular antioxidants and the PK2/PKR2 pathway and inhibiting the JAK2/STAT3 and NLRP3/caspase-1 pro-inflammatory pathways. Hence, arbutin may be used as an adjunct agent for mitigating Pb-induced testicular impairment.

Individual and combined effects of cadmium and lead exposure in rats

The exposure of humans and animals to environmental compounds is rarely restricted to a single chemical. Cadmium (Cd) and lead (Pb) are two heavy metals known to be the most toxic. Deleterious effects of each metal alone are well documented. Unfortunately, very few studies were conducted to determine their combined effect. Four groups of Wistar rats were treated intravenously for 15 days. The control group received physiological saline solution; groups 2 and 3 were treated with Cd chloride and lead acetate, respectively ; and the treatment group 4 received a combined treatment of Cd and Pb . A significant decrease was recorded for hematological parameters , with an increase in white blood cells and an inhibition in δ-ALAD level. Cell injury in the livers and kidneys was clearly shown by the significant elevation of the biochemical markers. Cd and Pb induced oxidative stress and had adverse health effects at lower exposure levels than previously thought.

Naringenin mitigates cadmium-induced cell death, oxidative stress, mitochondrial dysfunction, and inflammation in KGN cells by regulating the expression of sirtuin-1

The objective of this study was to examine the potential protective role of naringenin against the harmful effects induced by cadmium in KGN cell line. Cell viability was evaluated by cell counting kit-8 assay. Caspase-3/-9 activities were determined by caspase-3/-9 activity assay kits, respectively. Intracellular reactive oxygen species (ROS) level was detected by ROS-Glo™ H2O2 Assay, antioxidant capacity was determined by a total antioxidant capacity assay kit. Mitochondrial membrane potential (MMP), ATP level, and ATP synthase activity were determined by JC-1, ATP assay kit, and ATP synthase activity assay kit, respectively. The mRNA expression was determined by qRT-PCR. Cadmium reduced cell viability and increased caspase-3/-9 activities in a concentration-dependent manner. Naringenin improved cell viability and reduced caspase-3/-9 activities in cadmium-stimulated KGN cells in a concentration-dependent manner. Cadmium diminished the antioxidant capacity, increased ROS production, and induced mitochondrial dysfunction in KGN cells. These effects were ameliorated by naringenin treatment in a concentration-dependent manner. Furthermore, naringenin reduced the levels of pro-inflammatory cytokines in KGN cells exposed to cadmium. SIRT1 knockdown downregulated its expression in KGN cells and compromised the protective effects of naringenin on cell viability and caspase-3/-9 activities in cadmium-stimulated KGN cells. Naringenin prevented the reduction of MMP, ATP levels, and ATP synthase activity in cadmium-stimulated KGN cells in a concentration-dependent manner. However, these protective effects were significantly reversed by SIRT1 knockdown. In conclusion, this study suggests that naringenin protects against cadmium-induced damage by regulating oxidative stress, mitochondrial function, and inflammation in KGN cells, with SIRT1 playing a potential mediating role.

Assessment of the Impact of Trace Essential Metals on Cancer Development

This study examines the impact of zinc, copper, cobalt, iron, and manganese on cancer development, considering their dual roles as potential promoters or inhibitors within tumorigenesis. A comprehensive analysis of existing literature and experimental data is conducted to elucidate the intricate relationship between these trace elements and cancer progression. The findings highlight the multifaceted effects of zinc, copper, cobalt, iron, and manganese on various aspects of cancer development, including cell proliferation, angiogenesis, and metastasis. Understanding the nuanced interactions between these trace elements and cancer could offer crucial insights into tumorigenesis mechanisms and facilitate the identification of novel biomarkers and therapeutic targets for cancer prevention and treatment strategies. This research underscores the importance of considering the roles of essential trace elements in cancer biology and may ultimately contribute to advancements in precision medicine approaches for combating cancer.

Effects of environmental metal and metalloid pollutants on plants and human health: exploring nano-remediation approach

Metal and metalloid pollutants severely threatens environmental ecosystems and human health, necessitating effective remediation strategies. Nanoparticle (NPs)-based approaches have gained significant attention as promising solutions for efficient removing heavy metals from various environmental matrices. The present review is focused on green synthesized NPs-mediated remediation such as the implementation of iron, carbon-based nanomaterials, metal oxides, and bio-based NPs. The review also explores the mechanisms of NPs interactions with heavy metals, including adsorption, precipitation, and redox reactions. Critical factors influencing the remediation efficiency, such as NPs size, surface charge, and composition, are systematically examined. Furthermore, the environmental fate, transport, and potential risks associated with the application of NPs are critically evaluated. The review also highlights various sources of metal and metalloid pollutants and their impact on human health and translocation in plant tissues. Prospects and challenges in translating NPs-based remediation from laboratory research to real-world applications are proposed. The current work will be helpful to direct future research endeavors and promote the sustainable implementation of metal and metalloid elimination.

Preconception depression reduces fertility: a couple-based prospective preconception cohort

STUDY QUESTION

Is preconception depression associated with time to pregnancy (TTP) and infertility?

SUMMARY ANSWER

Couples with preconception depression needed a longer time to become pregnant and exhibited an increased risk of infertility.

WHAT IS KNOWN ALREADY

Preconception depression in women contributes to impaired fertility in clinical populations. However, evidence from the general population-especially based on couples-is relatively scant.

STUDY DESIGN SIZE DURATION

A couple-based prospective preconception cohort study was performed in 16 premarital examination centers between April 2019 and June 2021. The final analysis included 16 521 couples who tried to conceive for ≤6 months at enrollment. Patients with infertility were defined as those with a TTP ≥12 months and those who conceived through ART.

PARTICIPANTS/MATERIALS SETTING METHODS

Couples' depression was assessed using the Patient Health Questionnaire-9 at baseline. Reproductive outcomes were obtained via telephone at 6 and 12 months after enrollment. Fertility odds ratios (FORs) and infertility risk ratios (RRs) in different preconception depression groups were analyzed using the Cox proportional-hazard models and logistic regression, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 16 521 couples analyzed, 10 834 (65.6%) and 746 (4.5%) couples achieved pregnancy within the first 6 months and between the 6th and 12th months, respectively. The median (P25, P75) TTP was 3.0 (2.0, 6.0) months. The infertility rate was 13.01%. After adjusting for potential confounders, in the individual-specific analyses, we found that preconception depression in women was significantly related to reduced odds of fertility (FOR = 0.947, 95% CI: 0.908-0.988), and preconception depression in either men or women was associated with an increased risk of infertility (women: RR = 1.212, 95% CI: 1.076-1.366; men: RR = 1.214, 95% CI: 1.068-1.381); in the couple-based analyses, we found that-compared to couples where neither partner had depression-the couples where both partners had depression exhibited reduced fertility (adjusted FOR = 0.904, 95% CI: 0.838-0.975). The risk of infertility in the group where only the woman had depression and both partners had depression increased by 17.8% (RR = 1.178, 95% CI: 1.026-1.353) and 46.9% (RR = 1.469, 95% CI: 1.203-1.793), respectively.

LIMITATIONS REASONS FOR CAUTION

Reporting and recall bias were unavoidable in this large epidemiological study. Some residual confounding factors-such as the use of anti-depressants and other medications, sexual habits, and prior depressive and anxiety symptoms-remain unaddressed. We used a cut-off score of 5 to define depression, which is lower than prior studies. Finally, we assessed depression only at baseline, therefore we could not detect effects of temporal changes in depression on fertility.

WIDER IMPLICATIONS OF THE FINDINGS

This couple-based study indicated that preconception depression in individuals and couples negatively impacts couples' fertility. Early detection and intervention of depression to improve fertility should focus on both sexes.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the National Natural Science Foundation of China (No. 82273638) and the National Key Research and Development Program of China (No. 2018YFC1004201). All authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Prenatal double-hit with aluminium and cadmium mediate testicular atrophy and hypothalamic hypoplasia: the role of oxido-nitrergic stress and endocrine perturbations

There is limited experimental evidence on the biochemical consequences of aluminium (Al) and cadmium (Cd) co-exposures during pregnancy and postnatal life.This study investigated the impacts of perinatal Al chloride (AlCl3) and Cd chloride (CdCl2) co-exposures on neuroendocrine functions in mice offspring during postnatal life. The study comprised of four pregnant experimental groups. Group 1 received AlCl3 (10 mg/kg), group 2 were administered CdCl2 (1.5 mg/kg), while group 3 received both AlCl3 (10 mg/kg) and CdCl2 (1.5 mg/kg) (AlCl3+CdCl2), and group 4 received saline (10 mL/kg) only and served as control group. All experimental animals were chemically exposed once daily from gestation days 7-20. Upon delivery, male pups were regrouped based on maternal chemical exposure on postnatal day 21 (PND 21) and allowed to grow to adulthood until PND 78, after which they were sacrificed for assessment of neuroendocrine markers and histological investigations. There was no statistical significance (p > 0.05) on follicle stimulating hormone, testosterone, estrogen and progesterone, thyroid stimulating hormone, thyroxine (T4) in all treatment groups relative to controls|. However, AlCl3 and AlCl3-CdCl2 significantly (p < 0.05) reduced triiodothyronine (T3) levels, with a profound increase in T3:T4 ratio by AlCl3, and AlCl3+CdCl2 compared to control. Furthermore, pups from pregnant mice treated with CdCl2 and AlCl3+CdCl2 demonstrated increased testicular malondialdehyde concentration with increased catalase activity relative to controls, suggesting oxidative imbalance. In addition, AlCl3, CdCl2, and AlCl3+CdCl2 exposures induced testicular and hypothalamic architectural disruption compared to controls, with marked architectural derangement in the AlCl3+CdCl2 group. Our findings suggest that prenatal co-exposures to Alcl3 and CdCl2 induce testicular and hypothalamic alterations in offspring via a testicular oxidative stress and thyrotoxicosis-dependent mechanisms.

Emerging insights into the impacts of heavy metals exposure on health, reproductive and productive performance of livestock

Heavy metals, common environmental pollutants with widespread distribution hazards and several health problems linked to them are distinguished from other toxic compounds by their bioaccumulation in living organisms. They pollute the food chain and threaten the health of animals. Biologically, heavy metals exhibit both beneficial and harmful effects. Certain essential heavy metals such as Co, Mn, Se, Zn, and Mg play crucial roles in vital physiological processes in trace amounts, while others like As, Pb, Hg, Cd, and Cu are widely recognized for their toxic properties. Regardless of their physiological functions, an excess intake of all heavy metals beyond the tolerance limit can lead to toxicity. Animals face exposure to heavy metals through contaminated feed and water, primarily as a result of anthropogenic environmental pollution. After ingestion heavy metals persist in the body for an extended duration and the nature of exposure dictates whether they induce acute or chronic, clinical or subclinical, or subtle toxicities. The toxic effects of metals lead to disruption of cellular homeostasis through the generation of free radicals that develop oxidative stress. In cases of acute heavy metal poisoning, characteristic clinical symptoms may arise, potentially culminating in the death of animals with corresponding necropsy findings. Chronic toxicities manifest as a decline in overall body condition scoring and a decrease in the production potential of animals. Elevated heavy metal levels in consumable animal products raise public health concerns. Timely diagnosis, targeted antidotes, and management strategies can significantly mitigate heavy metal impact on livestock health, productivity, and reproductive performance.

Could the gut microbiota be capable of making individuals more or less susceptible to environmental toxicants?

Environmental toxicants are chemical substances capable to impair environmental quality and exert adverse effects on humans and other animals. The main routes of exposure to these pollutants are through the respiratory tract, skin, and oral ingestion. When ingested orally, they will encounter trillions of microorganisms that live in a community - the gut microbiota (GM). While pollutants can disrupt the GM balance, GM plays an essential role in the metabolism and bioavailability of these chemical compounds. Under physiological conditions, strategies used by the GM for metabolism and/or excretion of xenobiotics include reductive and hydrolytic transformations, lyase and functional group transfer reactions, and enzyme-mediated functional transformations. Simultaneously, the host performs metabolic processes based mainly on conjugation, oxidation, and hydrolysis reactions. Thus, due to the broad variety of bacterial enzymes present in GM, the repertoire of microbial transformations of chemicals is considered a key component of the machinery involved in the metabolism of pollutants in humans and other mammals. Among pollutants, metals deserve special attention once contamination by metals is a worldwide problem, and their adverse effects can be observed even at very low concentrations due to their toxic properties. In this review, bidirectional interaction between lead, arsenic, cadmium, and mercury and the host organism and its GM will be discussed given the most recent literature, presenting an analysis of the ability of GM to alter the host organism's susceptibility to the toxic effects of heavy metals, as well as evaluating the extent to which interventions targeting the microbiota could be potential initiatives to mitigate the adverse effects resulting from poisoning by heavy metals. This study is the first to highlight the overlap between some of the bacteria found to be altered by metal exposure and the bacteria that also aid the host organism in the metabolism of these metals. This could be a key factor to determine the beneficial species able to minimize the toxicity of metals in future therapeutic approaches.

Parental treatment with selenium protects Caenorhabditis elegans and their offspring against the reproductive toxicity of mercury

Mercury (Hg) is one of the major pollutants in the environment, which requires effective countermeasures to manage its risk to both human health and the ecosystem. The antagonistic effect of selenium (Se) against methyl mercury (MeHg) and HgCl2 was evaluated using parent and offspring Caenorhabditis elegans (C. elegans) in this study. Through designated acute exposure of 24 h, our results showed that both MeHg and HgCl2 induced dose-dependent reproductive toxicity, including increased germ cell apoptosis, decrease in the number of oocytes, brood size, and sperm activation. The increased germ cell apoptosis was even higher in F1 and F2 generations, but returned to control level in F3 generation. Pretreatment with Se significantly suppressed the reproductive toxicity caused by Hg in both parental worms and their offspring, but had little influence on Hg accumulation. The protective role of Se was found closely related to the chemical forms of Hg: mtl-1 and mtl-2 genes participated in reducing the toxicity of HgCl2, while the gst-4 gene was involved in the reduced toxicity of MeHg. The formation of Se-Hg complex and the antioxidant function of Se were considered as possible antagonistic mechanisms. Our data indicated that pretreatment with Se could effectively protect C. elegans and their offspring against the reproductive toxicity of Hg in different chemical forms, which provided a reference for the prevention of Hg poisoning and essential information for better understanding the detoxification potential of Se on heavy metals.

Sodium acetate abates lead-induced sexual dysfunction by upregulating testosterone-dependent eNOS/NO/cGMP signaling and activating Nrf2/HO-1 in male Wistar rat

Oxidative stress has been linked with lead toxicity, including lead-induced sexual dysfunction. On the contrary, sodium acetate has been proven to exert antioxidant activity. However, the effect of sodium acetate on lead-induced sexual dysfunction has not been fully explored. This study investigated the effect of sodium acetate on lead-induced sexual dysfunction, exploring the involvement of testosterone, eNOS/NO/cGMP, and Nrf2/HO-1 signaling. Twenty male Wistar rats with similar weights were randomly assigned into four groups (n = 5 rats/group) after two weeks of acclimatization. Animals were vehicle-treated (0.5 ml/day of distilled water, per os), acetate-treated (200 mg/kg/day, per os), lead-treated (20 mg/kg/day, per os), or lead + acetate-treated. The results revealed that sodium acetate treatment attenuated lead-induced rise in penile lead, malondialdehyde and oxidized glutathione concentrations, and acetylcholinesterase activity. In addition, lead exposure prolonged mount, intromission, and ejaculation latency and reduced mount, intromission, and ejaculation frequency, as well as the motivation to mate and penile reflex, which were improved by acetate treatment. More so, acetate treatment ameliorated lead-induced reductions in absolute and relative penile weight, eNOS, NO, cGMP, luteinizing hormone, follicle-stimulating hormone, testosterone, dopamine, Nrf2, HO-1, and reduced glutathione concentrations, as well as glutathione reductase, glutathione peroxidase, glutathione-S-transferase, superoxide dismutase, and catalase activities. In conclusion, this study demonstrates that sodium acetate attenuated lead-induced sexual dysfunction by upregulating testosterone-dependent eNOS/NO/cGMP and Nrf2/HO-1 signaling. Despite the compelling data presented in this study, other possible associated mechanisms in the protective role of acetate should be explored.

Associations of five blood heavy metals with hepatitis B virus infection and immunity in adults: a cross-sectional study

BACKGROUND

Heavy metal pollution has emerged as a significant concern for human health, prompting increased awareness of its potential adverse effects. While previous research has established a connection between heavy metals and liver function biomarkers, the specific relationship between heavy metals and HBV infection remains unexplored. This cross-sectional study aims to investigate the potential correlations between five blood heavy metals - lead, cadmium, mercury, manganese, and selenium - and the presence of HBsAg, HBsAb, and HBcAb in adults.

METHODS

The study utilized data from NHANES 2007-2018. Participants were classified into four groups based on their infectious status, and the association between heavy metals and HBV infection was analyzed using multiple logistic regression and stratification analysis.

RESULTS

A total of 8431 participants were included, with 5 436 classified as Susceptible, 1 765 as Vaccinated, 865 as Natural Infection, and 103 as Acute/Chronic HBV Infection. The Vaccinated group exhibited a lower mean age (34.52 ± 14.16 years) compared to the other groups. Statistically significant differences in heavy metal concentrations (except selenium) were observed among the groups (P < 0.001). After adjusting for covariates, lead was significantly associated with HBV infection (Q2: OR 2.37, 95%CI 1.04-5.39; Q3: OR 2.34, 95%CI 1.01-5.40), and positive trends were observed for high blood concentrations of mercury (Q4: OR 3.03, 95%CI 1.31-7.04) and manganese (Q4: OR 2.52, 95%CI 1.20-5.28). Furtherly, the presence of lead reduced the protection of HBsAb (Q2: OR 0.84, 95%CI 0.73-0.97; Q3: OR 0.77, 95%CI 0.66-0.90; Q4: OR 0.83, 95%CI 0.70-0.98). Subgroup analysis indicated that cadmium was associated with an increased risk of HBV infection in Asians (OR 1.36, 95%CI 1.03-1.78) and individuals with a BMI range of 25 to 30 (OR 1.60, 95%CI 1.17-2.18).

CONCLUSIONS

The study's findings suggest a correlation between elevated blood Pb concentrations and reduced immunization rates against hepatitis B. Individuals with a positive HBsAg exhibit lower blood Se concentrations and higher blood Hg and Mn concentrations.

Effect of ambient lead on progesterone and pregnancy-associated glycoprotein 1 and their relationship with abortion in Zaraibi goats: a field study

This study aimed to investigate the impact of ambient lead (Pb) exposure on progesterone (P4) and pregnancy-associated glycoprotein 1 (PAG1) and their relationship with abortion in Egyptian Zaraibi goats (C. hircus). To achieve this, 40 female goats (does) were mated with highly fertile male goats, resulting in a total of 28 pregnant goats. Eight of them aborted, and each of the 12 pregnant goats gave birth to one kid, whereas the remaining eight gave birth to twins. The levels of PAG1, P4, and Pb in serum were estimated by enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), and inductively coupled plasma mass spectrometry (ICP-MS) respectively. Statistically, the repeated measure two-way ANOVA, regression analysis, correlation coefficient, and receiver operating characteristic (ROC) curves were applied. The current data demonstrated that the levels of blood Pb in aborted goats were significantly higher than those in non-aborted goats at the early, mid, and late gestations, and this was followed by significant decreases in serum PAG1 and P4. Furthermore, there were substantial inverse associations between blood Pb concentration and levels of PAG1 and P4, with markedly negative correlation coefficients of - 0.88 and - 0.77, respectively, in aborted goats. The threshold level of Pb required to cause abortion was ≥ 32.08 μg/dl, but for PAG1 and P4 were respectively ≤ 0.95 ng/ml and ≤ 0.48 ng/ml. Additionally, threshold levels of ≥ 12.34 ng/ml and ≥ 31.52 ng/ml for P4 and PAG1, respectively, were needed to deliver twins. In conclusion, pollution-induced increases in Pb bioavailability resulted in dramatic decreases in P4 and PAG1 levels, leading to abortions. PAG1 and P4 levels are also key factors in determining whether Zaraibi goats will give birth to twins.

Geochemical landscapes as drivers of wildlife reproductive success: Insights from a high-Arctic ecosystem

The bioavailability of essential and non-essential elements in vegetation is expected to influence the performance of free-ranging terrestrial herbivores. However, attempts to relate the use of geochemical landscapes by animal populations directly to reproductive output are currently lacking. Here we measured concentrations of 14 essential and non-essential elements in soil and vegetation samples collected in the Zackenberg valley, northeast Greenland, and linked these to environmental conditions to spatially predict and map geochemical landscapes. We then used long-term (1996-2021) survey data of muskoxen (Ovibos moschatus) to quantify annual variation in the relative use of essential and non-essential elements in vegetated sites and their relationship to calf recruitment the following year. Results showed that the relative use of the geochemical landscape by muskoxen varied substantially between years and differed among elements. Selection for vegetated sites with higher levels of the essential elements N, Cu, Se, and Mo was positively linked to annual calf recruitment. In contrast, selection for vegetated sites with higher concentrations of the non-essential elements As and Pb was negatively correlated to annual calf recruitment. Based on the concentrations measured in our study, we found no apparent associations between annual calf recruitment and levels of C, Mn, Co, Zn, Cd, Ba, Hg, and C:N ratio in the vegetation. We conclude that the spatial distribution and access to essential and non-essential elements are important drivers of reproductive output in muskoxen, which may also apply to other wildlife populations. The value of geochemical landscapes to assess habitat-performance relationships is likely to increase under future environmental change.

Transcriptomic characterization of interactions between sodium selenite and coenzyme Q10 on preventing cadmium-induced testicular defects

The effect of heavy metal cadmium (Cd) on testicular function is recognized. However, the mechanism involved is not well-established. In the present study, we analyzed the testicular transcriptomic changes induced by acute Cd exposure of adult rats with and without supplementation of antioxidants selenium (Se) and/or coenzyme Q10 (CoQ). Cd significantly decreased serum testosterone and two steroidogenic proteins SCARB1 and STAR. RNA-Seq analyses of testicular RNAs revealed specific activation of oxidative stress-, inflammation-, MAPK- and NF-κB-related signaling molecules. In addition, Cd treatment down-regulated gene for I, III and IV complexes of mitochondrial electron transport chain and up-regulated genes for NADPH-oxidase, major cascade in ROS production. The decrease in steroidogenesis and increase in inflammation may result from oxidative stress since supplementation of Se and CoQ, but not with either alone, almost completely prevented these changes, including overall alterations in transcriptome. Cd exposure induced total of 1192 differentially expressed genes (DEGs), which was reduced to 29 without considering confounding factors associated with Se/CoQ, a 97.6% protection rate. In conclusion, Cd exposure inhibited Leydig cell steroidogenesis by down-regulating SCARB1 and STAR through increasing oxidative stress and inflammation, but Se plus CoQ synergistically prevented all the changes induced by the Cd exposure.

Zinc and α-tocopherol protect the antral follicles and endogenous antioxidants of female albino rats (Rattus norvegicus) against lead toxicity

BACKGROUND

Lead impairs female reproductive health because it can induce oxidative stress. Zinc as an antioxidant produces an enzyme system that helps neutralize free radicals. α-Tocopherol has an antagonistic effect that reduces oxidative stress. This study aimed to demonstrate the effects of zinc (Zn) and α-tocopherol on the ovarian endogenous antioxidants and antral follicles of albino rats (Rattus norvegicus) exposed to lead acetate (Pb(C2H3O2)2).

METHODS

Twenty-five female Wistar rats were divided into five groups, namely groups K (control), P0, P1, P2, and P3. Following exposure and treatment for 21 days with different combinations, the albino rats were necropsied, and their ovaries were removed for subsequent histopathological preparations and endogenous antioxidant analysis. Observations were made on the ovary, including an antral follicle count and diameter calculations. Analysis of the superoxide dismutase (SOD) levels (560 nm wavelength) and malondialdehyde MDA-TBA (532 nm wavelength) were performed by a spectrophotometer. The data were analyzed using a one-way ANOVA and least significant difference (LSD) test with the SPSS V24 software.

RESULTS

The highest SOD enzyme expression in the albino rat ovaries was in P0 (17.23 ± 5.34), and the lowest was in P3 (4.21 ± 0.76). The lowest MDA level was observed in the control group (K) and P3 compared to the other groups. The highest average antral follicle count and diameter were found in the albino rats exposed to 1.5 mg/kg BW lead acetate, and treated with 0.54 mg/kg BW zinc sulfate and 100 mg/kg BW α-tocopherol (group P3) compared to the other groups. The mechanisms of action of zinc and α-tocopherol work synergistically to decrease free radicals and ovarian damage.

CONCLUSION

The results showed that a combination of 0.54 mg/kg BW zinc (Zn) and 100 mg/kg BW α-tocopherol can maintain the number and diameter of the antral follicles and reduce ovarian SOD expression and MDA levels in albino rats exposed to lead acetate.