Arsenic trioxide exposure impairs testicular morphology in adult male mice and consequent fetus viability

Gut-gonad crosstalk in mice exposed to a "chemical cocktail" combining metabolomics and microbial profile by amplicon sequencing

Testes are very prone to be damaged by environmental pollutants, but there is a lack of information about the impact of "chemical cocktails" (CC) on the testicular metabolome and the possible influence in the gut-gonad crosstalk. For this, BALB/c mice were given flumequine and diclofenac orally in food and potentially toxic trace elements (Cd, Hg, As) in drinking water. A mice group was supplemented with selenium, a well-known antagonist against many pollutants. Our results revealed that the steroid 5-alpha-androstan-17-beta-ol propionate, suggested as a parameter of androgenicity independent of testosterone levels, proline that improves reproductive indicators in male rabbits affected by environmental stress) among others metabolites are only present after CC exposure with rodent and selenium supplemented diet. Selenium also antagonized the up-or down-regulation of anandamide (20:l, n-9) (p < 0.001 and FC 0.54 of CC vs C but p > 0,05 and FC 0.74 of CC-Se vs C), that regulates gonadotropin-releasing hormones in mammals, 2,3-dinor-11b-PGF2a (p < 0.001 and FC 0.12 of CC vs C but p > 0,05 and FC 0.34 of CC-Se vs C), which has been related with reproductive hormones, besides others testicular metabolites altered by the exposure to the CC and reversed the levels to control. Moreover, numerous significant associations between gut microbes and testicular metabolites indicated a possible impact of pollutants in the testes mediated by gut microbiota due to a gut-gonad crosstalk.

Research progress on arsenic, arsenic-containing medicinal materials, and arsenic-containing preparations: clinical application, pharmacological effects, and toxicity

Introduction: The toxicity of arsenic is widely recognized globally, mainly harming human health by polluting water, soil, and food. However, its formulations can also be used for the clinical treatment of diseases such as leukemia and tumors. Arsenic has been used as a drug in China for over 2,400 years, with examples such as the arsenic-containing drug realgar mentioned in Shennong's Herbal Classic. We have reviewed references on arsenic over the past thirty years and found that research has mainly focused on clinical, pharmacological, and toxicological aspects. Results and Discussion: The finding showed that in clinical practice, arsenic trioxide is mainly used in combination with all-trans retinoic acid (ATRA) at a dose of 10 mg/d for the treatment of acute promyelocytic leukemia (APL); realgar can be used to treat acute promyelocytic leukemia, myelodysplastic syndrome, and lymphoma. In terms of pharmacology, arsenic mainly exerts anti-tumor effects. The dosage range of the action is 0.01-80 μmol/L, and the concentration of arsenic in most studies does not exceed 20 μmol/L. The pharmacological effects of realgar include antiviral activity, inhibition of overactivated lactate dehydrogenase, and resistance to malaria parasites. In terms of toxicity, arsenic is toxic to multiple systems in a dose-dependent manner. For example, 5 μmol/L sodium arsenite can induce liver oxidative damage and promote the expression of pro-inflammatory factors, and 15 μmol/L sodium arsenite induces myocardial injury; when the concentration is higher, it is more likely to cause toxic damage.

Assessing the impact and mechanisms of environmental pollutants (heavy metals and pesticides) on the male reproductive system: a comprehensive review

The escalation of technological advancements, coupled with the increased use of hazardous chemicals, has emerged as a significant concern for human health. Exposure to environmental pollutants like heavy metals and pesticides (insecticides, herbicides and fungicides) is known to significantly contribute to various health problems, particularly affecting reproductive health. Disturbances in reproductive potential and reproductive toxicity in males are particularly worrisome. Existing literature suggests that exposure to these environmental pollutants significantly alters male reproductive parameters. Thus, it is imperative to thoroughly analyze, comprehend, and evaluate their impact on male reproductive toxicity. Oxidative stress and disruptions in redox equilibrium are major factors through which these pollutants induce changes in sperm parameters and affect the reproductive system. Insecticides, fungicides, and herbicides act as endocrine disruptors, interfering with the secretion and function of reproductive hormones such as testosterone and luteinizing hormone (LH), consequently impacting spermatogenesis. Additionally, heavy metals are reported to bio-accumulate in reproductive organs, acting as endocrine disruptors and triggering oxidative stress. The co-operative association of these pollutants can lead to severe damage. In this comprehensive review, we have conducted an in-depth analysis of the impact of these environmental pollutants on the male reproductive system, shedding light on the underlying mechanisms of action.

Toxicology of arsenate, arsenite, cadmium, lead, chromium, and nickel in testes of adult Swiss mice after chronic exposure by intraperitoneal route

BACKGROUND

Some residues such as the heavy metals cadmium (Cd), lead (Pb), chromium (Cr VI), nickel (Ni), and arsenic (As), this last one in its oxidized forms + 5 (arsenate) and + 3 (arsenite), can cause injuries to human health, so they are currently considered environmental health emergencies. In the testis, heavy metals can cause morphological and functional damage due to constant exposure acting chronically in individuals. Thus, we aimed to determine the toxicological mechanism of As+5, As+3, Cd, Cr VI, and Ni that leads to testicular damage and establish for the first time an order of toxicity among these studied heavy metals.

METHODS

Forty-two Swiss mice at reproductive age (140 days) were used, randomly distributed into seven experimental groups (n = 6). Exposure to heavy metals was weekly performed, by intraperitoneal route. Group 1 received 0.7 mL 0.9% saline (control), and the other groups received 1.5 mg/ kg of As+5, As+3, Cd, Pb, Cr VI, or Ni, for six weeks.

RESULTS

These studied heavy metals did not accumulate in the testis tissue. However, exposure to Ni induced moderate pathologies in the seminiferous tubules, plus changes in the tunica propria, blood vessels, lymphatic space, and carbonyl protein levels. Cd exposure caused moderate tubular histopathologies and changes in the blood vessels and lymphatic space. Cr VI induced slight tubular histopathologies, changes in the lymphatic space, blood vessels, and SOD activity. Pb and As+3 exposure triggered moderate tubular pathologies and changes in the SOD activity and carbonyl protein levels, respectively. Finally, As+5 induced only slight tubular pathologies.

CONCLUSION

The testicular histopathologies caused by the studied heavy metals are mainly triggered by changes in testicular oxidative balance. Based on our findings of histomorphological alterations, the toxicity order among the heavy metals is Ni>Cd>Cr(VI)>PbAs+3 >As+5. However, considering oxidative stress results, we propose the following testicular toxicity order for these heavy metals: Ni>As+3 > Cd>Cr(VI)>Pb>As+5. Ni exposure shows the most harmful among the heavy metals to the testis.

Zinc and selenium attenuate quaternary heavy metal mixture-induced testicular damage via amplification of the antioxidant system, reduction in metal accumulation, inflammatory and apoptotic biomarkers

Heavy metals (HMs) such as cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) are highly toxic elements. They are often found together in nature as a heavy metal mixture (HMM) and are known to contribute to subfertility/infertility as environmental pollutants. This study aims to evaluate the potential benefits of treating HMM-induced testicular pathophysiology with zinc (Zn) and/or selenium (Se). Six-week-old male Sprague Dawley rats were grouped into 5 (n = 7). The control group received deionized water, while the other groups were treated with PbCl2 (20 mg kg-1), CdCl2 (1.61 mg kg-1), HgCl2 (0.40 mg kg-1), and Na2AsO3 (10 mg kg-1) in deionized water for 60 days. Additionally, groups III to V received Zn, Se, and Zn/Se, respectively, for 60 days. The study evaluated testis weight, metal accumulation, sperm analysis, FSH, LH, testosterone, prolactin, oxidative stress, antioxidants, pro-inflammatory and apoptotic markers, and presented structural changes in the testis as micrographs. HMM caused a significant increase in testis weight, metal accumulation, prolactin, oxidative stress, and pro-inflammatory and apoptotic markers, while significantly decreasing semen analysis, FSH, LH, and testosterone. Histology showed decreased spermatogenesis and spermiogenesis, as evidenced by the structure of the germ cells and spermatids. However, Zn, Se, or both ameliorated and reversed some of the observed damages. This study provides further evidence for the mitigative potential of Zn, Se, or both in reversing the damage inflicted by HMM in the testis, and as a countermeasure towards improving HM-induced decrease in public health fecundity.

Graphical abstract

Contemporary Comprehensive Review on Arsenic-Induced Male Reproductive Toxicity and Mechanisms of Phytonutrient Intervention

Arsenic (As) is a poisonous metalloid that is toxic to both humans and animals. Drinking water contamination has been linked to the development of cancer (skin, lung, urinary bladder, and liver), as well as other disorders such as diabetes and cardiovascular, gastrointestinal, neurological, and developmental damage. According to epidemiological studies, As contributes to male infertility, sexual dysfunction, poor sperm quality, and developmental consequences such as low birth weight, spontaneous abortion, and small for gestational age (SGA). Arsenic exposure negatively affected male reproductive systems by lowering testicular and accessory organ weights, and sperm counts, increasing sperm abnormalities and causing apoptotic cell death in Leydig and Sertoli cells, which resulted in decreased testosterone synthesis. Furthermore, during male reproductive toxicity, several molecular signalling pathways, such as apoptosis, inflammation, and autophagy are involved. Phytonutrient intervention in arsenic-induced male reproductive toxicity in various species has received a lot of attention over the years. The current review provides an in-depth summary of the available literature on arsenic-induced male toxicity, as well as therapeutic approaches and future directions.

Metabolomics as a valid analytical technique in environmental exposure research: application and progress

BACKGROUND

In recent years, studies have shown that exposure to environmental pollutants (e.g., radiation, heavy metal substances, air pollutants, organic pollutants) is a leading cause of human non-communicable diseases. The key to disease prevention is to clarify the harmful mechanisms and toxic effects of environmental pollutants on the body. Metabolomics is a high-sensitivity, high-throughput omics technology that can obtain detailed metabolite information of an organism. It is a crucial tool for gaining a comprehensive understanding of the pathway network regulation mechanism of the organism. Its application is widespread in many research fields such as environmental exposure assessment, medicine, systems biology, and biomarker discovery.

AIM OF REVIEW

Recent findings show that metabolomics can be used to obtain molecular snapshots of organisms after environmental exposure, to help understand the interaction between environmental exposure and organisms, and to identify potential biomarkers and biological mechanisms.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review focuses on the application of metabolomics to understand the biological effects of radiation, heavy metals, air pollution, and persistent organic pollutants exposure, and examines some potential biomarkers and toxicity mechanisms.

Multi-omics analyses reveal the mechanisms of Arsenic-induced male reproductive toxicity in mice

Arsenic (As), a widespread environmental contaminant, can induce serious male reproductive injury; however, the underlying mechanisms remain unclear. Multi-omics analyses, including transcriptome, proteome, and phosphoproteome could promote our understanding of As-induced male reproductive toxicity. Here, we established the reproductive injured mice model by intraperitoneal injection of NaAsO2 (8 mg/kg body weight), which was validated by reduced reproductive cells, sperm motility, and litter size. The followed multi-omics analyses of mice revealed that As exposure inhibited ATP production by decreasing the expression of proteins HK1, and GAPDHS, and the enzymatic activities of PDH and SDH. The inhibition of mitochondrial activity and increase in HDAC2 and MTA3 dysregulated the lysine acetylation levels of histone and global proteins. Specifically, the downregulated histones H4K5ac and H4K12ac and upregulated histone H3K9ac disordered the distribution of TP1 to interfere with spermatogenesis. Moreover, As could reduce the expression of COL1A1, RAB13, and LSR to disrupt the junctions between seminiferous tubules, and thereinto, the inhibition of RAB13 increased PKA-dependent phosphorylation. Our study reveals that As causes male reproductive toxicity through decreasing energy production, altering histone acetylation, and impairing cell junctions. Our findings provide basic data for further studies on As reproductive toxicity.

Interconnected soil iron and arsenic speciation effects on arsenic bioaccessibility and bioavailability: a scoping review

Extensive research has examined arsenic (As) bioavailability in contaminated soils and is routinely assessed using in vitro bioaccessibility (IVBA) assays. Analysis of differences in bioaccessibility measurements across IVBA assays and phases is expected to provide valuable insights into geochemical mechanisms controlling soil As bioaccessibility and bioavailability. Soil iron (Fe) content and As speciation are expected to significantly influence IVBA gastric and intestinal phases due to fluctuations in precipitation-dissolution chemistry and sorption reactivity as pH and assay chemical complexity changes. The aim of this review was to examine these relationships by 1) conducting a meta-analysis (n = 47 soils) determining the influence of total Fe on As bioaccessibility measurements and 5 IVBA assays and 2) investigating the effect of As speciation on gastric/intestinal phase IVBA and in vitro-in vivo correlations. Our findings indicate that soil Fe content and As speciation heterogeneity are important in elucidating variability of bioaccessibility measurements across IVBA assays and gastrointestinal phases. Greater focus on coupled As speciation and Fe precipitation chemistry may (1) improve our understanding of soil geochemical factors and assay constituents that influence As in vitro-in vivo correlations and (2) resolve variability in the precision of oral relative bioavailability (RBA) estimated using IVBA assays for soils possessing heterogenous As speciation and Fe composition.

OUP accepted manuscript

Objective

The central objective of this study was to investigate the cumulative effects restraint stress and sodium arsenite on reproductive health in male rats.

Methods

Healthy male Wistar rats were allocated into 4 groups (n = 8). Animals in group 1 served as controls and did not subjected to any stress. Rats in groups 2, 3, and 4 were subjected to either restraint stress (5 h/day) or maintained on arsenic (25 ppm) via drinking water or both for 65 days. After completion of the experimental period, all the rats were analyzed for selected reproductive endpoints.

Results

Restraint stress or sodium arsenite treatment increased serum corticosterone levels, reduced testicular daily sperm count, epididymal sperm viability, motility, membrane integrity, and decreased testicular steroidogenic enzymes such as 3β- and 17β-hydroxysteroid dehydrogenases associated with reduced serum testosterone levels, deteriorated testicular architecture, and reduced activity levels of testicular superoxide dismutase and catalase accompanied by elevated lipid peroxidation levels. In rats subjected to restraint stress and sodium arsenite, a significant decrease in selected sperm qualitative and quantitative parameters, serum testosterone levels were observed as compared with rats subjected to sodium arsenite alone. A significant increase in the levels of lipid peroxidation with a concomitant decrease in the activities of antioxidant enzymes was observed in the testis of rats subjected to both restraint stress and sodium arsenite treatment as compared with sodium arsenite alone intoxicated rats. Surprisingly, serum corticosterone levels were significantly elevated in rats following both stressors as compared with arsenic alone treated rats. Analysis of atomic absorption spectroscopy revealed that the accumulation of arsenic in the testis of arsenic-treated and arsenic plus immobilization stress groups was significant as compared with controls.

Conclusions

Based on the findings, it can be concluded that deterioration of male reproductive health could be accelerated in arsenic intoxicated rats following restraint stress.

Evaluation of toxic effects induced by arsenic trioxide or/and antimony on autophagy and apoptosis in testis of adult mice

Arsenic trioxide (ATO) and antimony (Sb) are well-known ubiquitous environmental contaminants and cause unpromising male reproductive effects in target and non-target exposed organisms. The main objective of this study was to investigate the effects of ATO or/and Sb on process of autophagy, apoptosis, and reproductive organ in adult mice. For this reason, a total of 32 adult mice were randomly divided into different groups like control group, ATO-treated group, Sb-treated group, and combined group. The duration of current experimental trial was 2 months. Various adverse effects of ATO or/and Sb on sperm parameters, oxidative stress, autophagy, and apoptosis were determined in testis of mice. Results indicated that parameters of sperm quality for organ coefficient, sperm count, ratio of sperm survival, testosterone level, and germ cells were significantly decreased, while malformation rate and vacuolization significantly increased in mice exposed to different treatments. Furthermore, the status of antioxidant index of T-AOC, SOD, and MsrB1 levels was reduced, while MDA increased significantly in ATO + Sb group. Results on TEM investigation determined that the autophagosomes, autolysosome, nuclear pyknosis, and chromatin condensation were prominent ailments, and the levels of autophagy and pro-apoptosis indictors including Beclin1, Atg-5, LC3B/LC3A, caspase-8, cytc, cleaved caspase-3, p53, and Bax were up-regulated in treated group, while the content of an anti-apoptosis maker (Bcl-2) was down-regulated. In conclusion, the results of our experiment suggested that abnormal process of autophagy and apoptosis was triggered by arsenic and antimony, and intensity of toxic effects increased in combined treatments of ATO and Sb.

Riboflavin recovery of spermatogenic dysfunction via a dual inhibition of oxidative changes and regulation of the PINK1-mediated pathway in arsenic-injured rat model

Arsenic trioxide (As2O3) poisoning and associated potential lesions are of a global concern. Inversely, riboflavin (vitamin B2, VB2) as a component of flavoproteins could play a vital role in the spermatogenic enzymatic reactions. Thus, this research aimed to explore potential beneficial roles of VB2 during As2O3-injured-toxicity. Rats were randomly allocated into 4 groups (n=8/group) and challenged as follows (for 30 days continuously): Group 1 received normal saline; Group 2 was treated with 3 mg As2O3/L; Group 3 received 40 mg VB2/L; Group 4 received 3 mg As2O3/L + 40 mg VB2/L. Both As2O3 and VB2 were dissolved in deionized water. Malondialdehyde (MDA), Glutathione Peroxidase (GSH-Px), Superoxide dismutase (SOD), and Catalase (CAT) were assessed for the oxidative profile, while TAS (Total Antioxidative Status) levels were evaluated for the antioxidant system, in both serum and testicular tissue. P<0.05 was considered statistically significant. The results show that As2O3 significantly decreased the body weight, testicular weight and testis volume, semen quality and testicular cell count (p<0.05). Furthermore, MDA content in the testicular tissue of the As2O3 group rats was significantly higher in comparison to the vehicle group (p<0.05). Likewise, TAS and the activities of GSH-Px, CAT and SOD were reduced (p<0.05) when compared to the control. As(2)O(3) induced testicular damage and seminiferous tubular atrophy. Monodansylcadaverine assays mirrored the histopathology observations. Meanwhile, As2O3 upregulated the expression of mitophagy-related genes including PINK1, Parkin, USP8, LC3-I, Fis1 and Mfn2. The p38 gene, responsible to stress stimuli, was also upregulated by As2O3 administration. Meanwhile, exposure to VB2 led to a significant decrease of the expression levels of mitophagy related genes. Our study revealed that VB2 supplementation protected testicular structures against As2O3-induced injury via a dual inhibition of oxidative changes and a regulation of the PINK1-mediated pathway.

Melatonin: a pleiotropic hormone as a novel potent therapeutic candidate in arsenic toxicity

BACKGROUND

Arsenic is a natural element which exists in the environment in inorganic and organic forms. In humans, the main reason for the toxicity of arsenic is its uptake via water sources. As polluted water and the problems associated with it can be found in many countries. Therefore, considering all these positive effects of melatonin, this review is aimed at melatonin supplementation therapy on arsenic toxicity which seems to be a suitable therapeutic agent to eliminate the adverse effects of arsenic.

METHODS AND RESULTS

It is seen in previous studies that chronic exposure to arsenic could cause serious dys functions of organs and induce different degrees of toxicities that is one of the first hazardous materials in the classification of substances by the United States Environmental Protection Agency so leads to costly cleanup operations burdening the economy. Arsenic harmfulness degree depends on the bioavailability, chemical form, valence state, detoxification, and metabolism of human body. The oxidative stress has a major role in arsenic-induced toxicity; on the other hand, it was discovered that melatonin is a powerful scavenger for free radical and it's an extensive-spectrum antioxidant.

CONCLUSION

Due to its highly lipophilic and small size properties, melatonin accesses all intracellular organs by easily passing via the cell membrane and prevents protein, DNA damage, and lipid peroxidation. In particular, melatonin, by protecting and reducing oxidative stress in mitochondria, can normalize homeostasis and mitochondrial function and ultimately prevent apoptosis and cell death.

Prepubertal arsenic exposure alters phosphoproteins profile, quality, and fertility of epididymal spermatozoa in sexually mature rats

Arsenic intoxication affects male reproductive parameters of prepubertal rats. Besides, morphological and functional alterations in their testis and epididymis may remain after withdrawal of arsenic insult, causing potential impairment in male fertility during adulthood. In this study, we aimed at analyzing the effect of prepubertal arsenic exposure on the fecundity of epididymal sperm from sexually mature Wistar rats, assessing fertility indexes, sperm parameters, and sperm phosphoproteins content. Male pups on postnatal day (PND) 21 received filtered water (controls, n = 10) and 10 mg L^-1 arsenite (n = 10) daily for 30 days. From PND52 to PND81, rats from both groups received filtered water. During this period, the males mated with non-exposed females between PND72 and PND75. Our results showed that sexually mature rats presented low sperm production, epididymal sperm count, motility, and quality after prepubertal arsenic exposure. These findings possibly contributed to the low fertility potential and high preimplantation loss. Epididymal sperm proteome detected 268 proteins, which 170 were found in animals from both control and arsenic groups, 27 proteins were detected only in control animals and 71 proteins only in arsenic-exposed rats. In these animals, SPATA 18 and other five proteins were upregulated, whereas keratin type II cytoskeletal 1 was downregulated (q < 0.1). The results of KEGG pathway analysis demonstrated an enrichment of pathways related to dopaminergic response, adrenergic signaling, protein degradation, and oocyte meiosis in arsenic-exposed animals. Moreover, 26 proteins were identified by phosphoproteomic with different phosphorylation pattern in animals from both groups, but SPATA18 was phosphorylated only in arsenic-exposed animals. We concluded that prepubertal exposure to arsenic is deleterious to sperm quality and male fertility, altering the sperm phosphoproteins profile.

Transgenerational effects in DNA methylation, genotoxicity and reproductive phenotype by chronic arsenic exposure

An emerging concern is the influences of early life exposure to environmental toxicants on offspring characteristics in later life. Since recent evidence suggests a transgenerational transference of aberrant phenotypes from exposed-parents to non-exposed offspring related to adult-onset diseases including reproductive phenotype. The transgenerational potential of arsenic a well know genotoxic and epigenetic modifier agent has not been assessed in mammals until now. In this experimental study, we evaluated the transgenerational effects of arsenic in a rat model with chronic exposure to arsenic. Rats chronically exposed to arsenic in drinking water (1 mg As₂O₃/mL) (F0) were mated to produce the arsenic lineage (F1, F2, and F3). The arsenic toxic effects on were evaluated over the four generations by analyzing the DNA methylation percentage, genotoxicity in WBC and physical and reproductive parameters, including sperm quality parameters and histopathological evaluation of the gonads. Chronic exposure to arsenic caused genotoxic damage (F0-F3) different methylation patterns, alterations in physical and reproductive parameters, aberrant morphology in the ovaries (F0 and F1) and testicles (F1-F3), and a decrease in the quality of sperm (F0-F3, except F2). Parental chronic arsenic exposure causes transgenerational genotoxicity and changes in global DNA methylation which might be associated with reproductive defects in rats. Combined with recent studies reveal that disturbances in the early life of an individual can affect the health of later generations.

Evaluation of testicular structure in mice after exposure to environmentally relevant doses of manganese during critical windows of development

Despite being an essential trace element with great importance for vital metabolic activities, the manganese (Mn) can also cause damage to organ systems. However, data on the effect of this metal on the male reproductive system are limited, especially using relevant doses to human exposure. The present study aimed to evaluate and compare the effects of Mn exposure on the testicular structure of mice. Three experiments were conducted: (I) direct exposure to realistic doses (0.013, 0.13, and 1.3 mg/kg/day of MnCl₂); (II) parental and direct exposure to realistic doses (as in experiment I), where the animals were exposed during intrauterine development and from lactation until reproductive maturity; (III) direct exposure to high doses (15, 30, and 60 mg/kg/day of MnCl₂). Biometric, histopathological, histomorphometric and stereological parameters of the testis were evaluated, in addition to sperm morphology. Bioinformatic analyses were performed to identify potential Mn binding sites in 3β-HSD and P450ssc, as well as their protein-protein interaction network. The results obtained were compared using the integrated biomarker response index (IBR). There was an increase of seminiferous tubules pathologies in all experimental conditions tested, with effects on tubular volume, as well as a reduction in tubular diameter. The IBR analyses showed that parental and direct exposure had a significant negative effect on the testicular structure due to the exposure of this metal to sensitive periods of animal development. This study suggests that Mn has the potential to alter the morphological parameters of the testes, affecting the spermatogenesis in mice.

The mechanisms of arsenic-induced ovotoxicity, ultrastructural alterations, and autophagic related paths: An enduring developmental study in folliculogenesis of mice

Arsenic (As) exerts a wide range of adverse effects on biological systems, including the reproductive organs in males and females. However, the mechanisms of As-induced reproductive toxicity are mostly obscure. Recently, we showed that autophagy is an essential route for As₂O₃-induced reprotoxicity through the hypothalamic-pituitary-gonadal-sperm (HPG-S) axis in pubertal and matured F1-male mice. However, the role of autophagy in As₂O₃- induced ovarian toxicity is mostly unknown. Hence, this study aimed to elucidate the role of oxidative stress, mitochondrial impairment, and autophagic processes in the ovary of As-exposed female mice. For this purpose, mature female mice were challenged with 0, low (0.2), medium (2), and high (20 ppm) As₂O₃ from 35-days before mating till weaning their pups, and the F1- females from weaning until maturity. Then, all the mice were sacrificed, and oxidative stress parameters, mitochondrial indices, electron microscopic evaluation of the ovaries, expression of autophagic-related genes and proteins, and autophagosome formation were assessed. It was shown that medium and high As₂O₃ doses were a potent inducer of oxidative stress, mitochondrial dysfunction, and autophagy in the ovary of F1-generation. A dose-dependent increment in the gene expression of PDK₁, PI3K, TSC2, AMPK, ULK1, ATG13, Beclin1, ATG12, ATG5, LC3, P62, ATG3, ATG7, and p62, as well as protein expression of Beclin1, and LC3- I, II, was evident in the ovaries of the As-treated animals. Moreover, a dose-dependent decrease in the expression of mTOR and Bcl-2 genes, and mTOR protein was detected with increasing doses of As, suggesting that As treatment-induced autophagy. Along with a dose-dependent increase in the number of MDC-labeled autophagic vacuoles, transmission electron microscopy also confirmed more autophagosomes and injured mitochondria in medium and high As₂O₃ doses groups. As₂O₃ also negatively affected the mean body weight, litter size, organ coefficient, and stereological indices in female mice. Finally, in physiological conditions, arsenic trioxide (As₂O₃) leads to an increased level of autophagy in the oocyte when many oocytes were being lost. These findings indicated that an imbalance in the oxidant-antioxidant system, mitochondrial impairment, and the autophagic process, through inhibition of mTOR, dependent and independent pathways, and Bcl-2, as well as activation of AMPK/PI3K/Beclin1/LC3 routes, could play a pivotal role in As-induced reproductive toxicity through ovarian dysfunction in females.

Arsenic induces dysfunctional autophagy via dual regulation of mTOR pathway and Beclin1-Vps34/PI3K complex in MLTC-1 cells

Arsenic poisoning and induced potential lesion is a global concern. However, the exact mechanisms underlying its toxicity especially in male reproductive system still remain unclear. Hence, this study aimed to explore the roles of mTOR and Beclin1-Vps34/PI3K complex during As-induced-toxicity using Rapamycin (mTOR inhibitor), Beclin1 siRNA and 3-methyladenine (3-MA, Vps34/PI3K inhibitor) in testicular stromal cells. For this, mouse testis Leydig Tumor Cell lines (MLTC-1) were challenged with As₂O₃ (0, 3, 6 and 9 μM) exposure for 24 hs. Lyso-Tracker Red and Monodansylcadaverine (MDC) staining results depicted a significant accumulation of autophagosomes in MLTC-1 cells exposed to arsenic. Meanwhile, arsenic treatment up-regulated autophagic markers including LC3, Atg7, Beclin1 and Vps34 expressions, mTOR downstream autophagy related genes and the Beclin1-Vps34/PI3K complex associated members. Furthermore, silencing of Beclin1, and inhibition of Vps34/PI3K and mTOR altered the arsenic-induced autophagosomes formation. However, p62, the substrate protein of autophagy, was also up-regulated by arsenic administration independent on Beclin1-Vps34/PI3K complex. Altogether, our results revealed that arsenic exposure induced autophagosomes formation via regulation of the Beclin1-Vps34/PI3K complex and mTOR pathway; the blockage of autophagosomes degradation maybe due to impaired function of lysosomes. Thus, this study provides a novel mechanistic approach with respect to As-induced male reproductive toxicity.

In utero exposure to arsenite contributes to metabolic and reproductive dysfunction in male offspring of CD-1 mice

In utero exposure to arsenite (iAs) is known to increase disease risks later in life. We investigated the effect of in utero exposure to iAs in the drinking water on metabolic and reproductive parameters in male mouse offspring at postnatal and adult stages. Pregnant CD-1 mice were exposed to iAs (as sodium arsenite) in the drinking water at 0 (control), 10 ppb (EPA standard for drinking water), and 42.5 ppm (tumor-inducing dose in mice) from embryonic day (E) 10-18. At birth, pups were fostered to unexposed females. Male offspring exposed to 10 ppb in utero exhibited increase in body weight at birth when compared to controls. Male offspring exposed to 42.5 ppm in utero showed a tendency for increased body weight and a smaller anogenital distance. The body weight in iAs-exposed pups continued to increase significantly compared to control at 3 weeks and 11 weeks of age. At 5 months of age, iAs-exposed males exhibited greater body fat content and glucose intolerance. Male offspring exposed to 10 ppb in utero had higher circulating levels of leptin compared to control. In addition, males exposed to 42.5 ppm in utero exhibited decreased total number of pups born compared to controls and lower average number of litters sired over a six-month period. These results indicate that in utero exposure to iAs at either human relevant concentration or tumor-inducing concentration is a potential cause of developmental origin of metabolic and reproductive dysfunction in adult male mice.

Toxic effects of arsenic trioxide on spermatogonia are associated with oxidative stress, mitochondrial dysfunction, autophagy and metabolomic alterations

Arsenic is a toxic metalloid that can cause male reproductive malfunctions and is widely distributed in the environment. The aim of this study was to investigate the cytotoxicity of arsenic trioxide (ATO) induced GC-1 spermatogonial (spg) cells. Our results found that ATO increased the levels of catalase (CAT) and malonaldehyde (MDA) and reactive oxygen species (ROS), while decreasing glutathione (GSH) and the total antioxidant capacity (T-AOC). Therefore, ATO triggered oxidative stress in GC-1 spg cells. In addition, ATO also caused severe mitochondrial dysfunction that included an increase in residual oxygen consumption (ROX), and decreased the routine respiration, maximal and ATP-linked respiration (ATP-L-R), as well as spare respiratory capacity (SRC), and respiratory control rate (RCR); ATO also damaged the mitochondrial structure, including mitochondrial cristae disordered and dissolved, mitochondrial vacuolar degeneration. Moreover, degradation of p62, LC3 conversion, increasing the number of acidic vesicle organelles (AVOs) and autophagosomes and autolysosomes are demonstrated that the cytotoxicity of ATO may be associated with autophagy. Meanwhile, the metabolomics analysis results showed that 20 metabolites (10 increased and 10 decreased) were significantly altered with the ATO exposure, suggesting that maybe there are the perturbations in amino acid metabolism, lipid metabolism, glycan biosynthesis and metabolism, metabolism of cofactors and vitamins. We concluded that ATO was toxic to GC-1 spg cells via inducing oxidative stress, mitochondrial dysfunction and autophagy as well as the disruption of normal metabolism. This study will aid our understanding of the mechanisms behind ATO-induced spermatogenic toxicity.

Arsenic-induced autophagic alterations and mitochondrial impairments in HPG-S axis of mature male mice offspring (F1-generation): A persistent toxicity study

Arsenic (As) has been implicated in causing reproductive toxicity, but the precise cellular pathway through which the As toxicity in mature F1- male mice hypothalamic-pituitary- gonadal- sperm (HPG-S) axis is induced has not well been documented. Hence, parental mice were treated to As₂O₃ (0, 0.2, 2, and 20 ppm in deionized water) from five weeks before mating until weaning, and the male pups from weaning to maturity. Afterward, the markers of oxidative stress, mitochondrial impairment, and autophagy as fundamental mechanisms of cytotoxicity and organ injury were evaluated. Higher As₂O₃ doses (2 and 20 ppm) were a potent inducer of oxidative stress, mitochondrial dysfunction, and autophagy in HPG-S axis. Concomitant with a dose-dependent increase in the number of MDC-labeled autophagic vacuoles in the HPG axis, an adverse dose-dependent effect was observed on the mean body weight, litter size, organ coefficient, and spermatogenesis. Transmission electron microscopy also revealed more autophagosomes at high As₂O₃ dosage. Concomitant with a dose-dependent increment in gene expression of PI3K, Atg5, Atg12, as well as protein expression of Beclin1, LC3- I, II, P62 in HPG axis tissues and Atg12 in the pituitary; a dose-dependent decrease in mTOR gene expression was recorded in the HPG tissues of mature F₁-males. These observations provide direct evidence that oxidative stress-induced mitochondrial impairments and autophagic cell death, through AMPK/TSC/mTOR and LC3 related pathways, are fundamental mechanisms for As₂O₃- induced toxicity on the reproductive system in mature male mice offspring.

Arsenic influences spermatogenesis by disorganizing the elongation of spermatids in adult male mice

Arsenic (As) has become a major problem in maintaining the environment and human health due to its wide application in the production of agriculture and industry. Many studies indicate that As can affect spermatogenesis process and lower sperm quality. However, the undergoing molecular mechanism is unclear. For this, forty-eight 8-week old adult male mice were divided into four groups of twelve each, which were administrated to 0, 0.2, 2, 20 ppm As₂O₃ in their drinking water respectively for six months. The results showed that As treatment reduced sperm counts and increased the sperm malformation ratio of mice. Interestingly, both the amounts of round and elongated spermatids, and the ratios of spermatids elongation were decreased significantly by As exposure. Furthermore, the structure of Chromatoid Body (CB) which presents a typical nebulous shape in round spermatids after spermatogenesis arrested, and the mRNA expression levels of gene TDRD1, TDRD6 and TDRD7 related to CB were changed by arsenic. Again, the mRNA and protein expression levels of the markers DDX25 and CRM1 in haploid periods of spermatogenesis and the associated proteins HMG2, PGK2, and H4 with DDX25 regulation were declined significantly with As treatment. Taken together; it reveals that As interferes with spermatogenesis by disorganizing the elongation of spermatids. H4, HMG2 and PGK2 are regulated by DDX25 which interacts with CRM1 and may play a vital role in spermatogenesis disorder induced by As exposure, which maybe provides one of the underlying mechanisms for As-induced male reproductive toxicity.

Arsenic in edible macroalgae: an integrated approach

Arsenic is a metalloid naturally present in marine environments. Various toxic elements including arsenic (As) are bioaccumulated by macroalgae. This metalloid is subsequently incorporated as arsenate into the organism due to similarity to phosphate. In recent decades, the use of macroalgae in food has increased as a result of their numerous benefits; however, As consumption may exert potential consequences for human health. The objective of this review was to discuss the articles published up to 2019 on As in seaweed, including key topics such as speciation, toxicity of the most common species in marine macroalgae, and their effects on human health. Further, this review will emphasize the extraction methods and analysis techniques most frequently used in seaweed and the need to develop certified reference materials (CRMs) in order to support the validation of analytical methodologies for As speciation in macroalgae. Finally, this review will discuss current legislation in relation to the risk associated with consumption. The number of articles found and the different approaches, biological, analytical and toxicological, show the growing interest there has been in this field in the last few years. In addition, this review reveals aspects of As chemistry that need further study, such as transformation of organic metalloid species during digestion and cooking, which necessitates analytical improvement and toxicological experiments. Taken together our findings may contribute to revision of current legislation on As content in edible seaweed relating to human health in a growing market.

Modeling dynamics and alternative treatment strategies in acute promyelocytic leukemia

Acute Promyelocytic Leukemia (APL) is a rare and potentially lethal condition in which risk-based therapy often leads to better outcomes. Because of its rarity and relatively high overall survival rate, prospective randomized trials to investigate alternative APL treatment schedules are challenging. Mathematical models may provide useful information in this regard. We collected clinical data from 38 patients treated for APL under the International Consortium on Acute Leukemia (ICAL) protocol and laboratory data during induction therapy. We propose a mathematical model that represents the dynamics of leukocytes in peripheral blood and the effect of ICAL treatment on the disease’s dynamics. We observe that our cohort presents demographic characteristics and clinical outcomes similar to previous clinical trials on APL. Over a follow-up period of 41.8 months, the relapse-free survival and overall survival at two years are both found to be 78.7%. For two selected patients, the model produces a good fit to the clinical data. Information such as the response to treatment and risk of relapse can be derived from the model, and this may assist in clinical practice and the design of clinical trials.

Metal/metalloid levels in urine and seminal plasma in relation to computer-aided sperm analysis motion parameters

BACKGROUND

Exposure to high levels of metals/metalloids may impair semen quality. Computer-aided sperm analysis (CASA) can be used for kinematic analysis of spermatozoa, which provides additional insights into sperm motion characteristics.

OBJECTIVE

To explore the associations of urinary and seminal plasma metal/metalloid concentrations with CASA motion parameters and assess the degree of correspondence between the two sample types.

METHODS

Eighteen metals/metalloids in seminal plasma and repeated urine samples were determined among 746 men recruited from a reproductive center. We assessed their associations with 6 CASA motion parameters [i.e., straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), linearity (LIN), straightness (STR) and amplitude head displacement (ALH)] using multivariable linear regression models.

RESULTS

We found significantly inverse dose-dependent relationships between seminal plasma arsenic (As) and VSL, VCL and VAP, between seminal plasma selenium (Se) and VSL and VAP, between seminal plasma zinc (Zn) and STR and LIN, and between seminal plasma manganese (Mn) and LIN in single-metal models [all false discovery rate (FDR) adjusted P for trend < 0.05]. These dose-response relationships remained statistically significant based on multiple-metal models and restricted cubic spline functions. Metal/metalloid concentrations in urine poorly predicted the same-day seminal plasma concentrations [coefficient of determination (R²) < 0.15]. We didn't find any significant associations between urinary metal/metalloid concentrations and the CASA motion parameters.

CONCLUSION

Exposure to high levels of As, Se, Mn and Zn may impair sperm motion capacity. Concentrations of metals/metalloids in spot urine samples cannot accurately predict same-day seminal plasma exposure levels.

Prepubertal exposure to low doses of sodium arsenite impairs spermatogenesis and epididymal histophysiology in rats

For the first time, juvenile toxicity of inorganic arsenic (As) was investigated in male rats, focusing on reproductive effects. As is a metalloid naturally occurring in the environment, being the inorganic forms the most toxics. Contaminated drinking water and agricultural products are the main prospectors of intoxication for general population. In the present study, Wistar male rats (21 days old) were distributed into three groups (n = 10/group): control (received vehicle-filtered drinking water), As1 (received AsNaO₂ at 0.01 mg L^-1 ) and As2 (received AsNaO₂ at 10 mg L^-1 ). The animals were euthanized on PND 53. Testicular damages increased in As1 and As2 compared to control (ie, presence of vacuolization, acidophilic cells, and epithelium degeneration). Testicular interstitium of As1 and As2 presented fluid's increase and intense inflammatory infiltration. In the epididymis there was reduction of sperm amount in the lumen, besides epithelium areas presenting cribriform aspect in As1 and As2, exfoliation of cells in the light (in As1) and vacuoles (in As2). In epididymis interstitium, inflammatory infiltrates were observed in initial segment of As1 and As2. AsNaO₂ changed immunolabeling pattern for androgen receptor in epididymis of As2, although serum testosterone levels was statistically comparable to control. Mass spectrometry revealed higher As concentrations in testis and epididymis of As2 compared to As1 and Control. These results indicate compromise of spermatogenesis and epididymal histophysiology in AsNaO₂ -treated animals, possibly impairing sperm quality and fertility in long-term, even at low levels of exposure. Investigations about the reversibility of reproductive damages are necessary to better understand the mechanisms of As reproductive toxicity.

Ellagic and ferulic acids protect arsenic-induced male reproductive toxicity via regulating Nfe2l2, Ppargc1a and StAR expressions in testis

Arsenic (As) - induced oxidative stress causes male reproductive toxicity apart from its other generalized systemic effects. Some phytochemicals through their antioxidant properties might help to overcome such toxic effects. The aim of the study was to elucidate the protective role of the selected phytochemicals, ellagic and ferulic acids against the As-induced reproductive toxicity. Forty two healthy male Swiss albino mice were randomly assigned to six groups (each @ n = 7). Group A served as the control, while group B received 200 ppm of As through drinking water. The group C and D mice were administered Per os (P.O) with 50 mg/kg BW of ellagic and ferulic acids, respectively on alternate days. Group E or F received 50 mg of ellagic or ferulic acid + 200 ppm of As for forty days. Ellagic and/ ferulic acid significantly reduced the accumulation of As, protein carbonylation (PC), lipid peroxidation (LPO) in addition to altering the antioxidant enzymes (CAT and SOD) activities, reduced glutathione (GSH) and total antioxidant capacity (TAC) in the testicular tissues. A significantly (p < 0.05) altered sperm functions (viability, functional membrane integrity, Δψ_m and sperm kinematics like total motility, rapid, progressive motile and type-A (STR > 80%, ALH > 2.5 μm) and testicular damage induced by the As were ameliorated (p < 0.05) by the phytochemical treatments. These phytochemicals due to their antioxidant activities were found to attenuate the As-induced oxidative stress, testicular damage, and sperm abnormalities via regulating the expressions of Nfe2l2, StAR and Ppargc1a. The study revealed that ellagic and ferulic acids might be potential therapeutic options to protect the male reproductive system from As-poisoning.

Non-cancer, cancer, and dermal sensitization risk assessment of heavy metals in cosmetics

The heavy metal content of cosmetics may be a cause for concern in that exposure to these metals is associated with adverse consequences. Thus, the aim of this study was to assess consequences attributed to exposure to heavy metals in cosmetics as determined by non-cancer, cancer, and sensitization risks methodologies. The quantification and exposure assessments of aluminum (Al), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), lead (Pb), mercury (Hg), cadmium (Cd), antimony (Sb), and titanium (Ti) were performed by inductively coupled plasma-mass spectrometry. The non-cancer risk assessment of Al, Cr³⁺, Mn, Fe, Co, Ni, Cu, Zn, Cd, Sb, and Ti in cosmetic samples resulted in a margin of safety (MOS) greater than 100 or a hazard index (HI) of less than 1. However, the probability of lifetime cancer risk (LCR) resulting from dermal exposure to heavy metals from cosmetics exceeded the acceptable risk levels (LCR > 10^-5). An exposure-based sensitization quantitative risk assessment determined that the ratios of acceptable exposure level to consumers for Ni, Co, Cu, or Hg were above 1, suggesting an absence of skin-sensitizing potential. For an average daily user of lip cosmetics, the estimated intakes of heavy metals were within the acceptable daily intake (ADI). The percentage of heavy users for which metal intakes exceeded ADIs were 20.37% for Pb, 9.26% for Mn, 1.85% for Cr³⁺, and 1.85% for Cr⁶⁺, respectively. Data suggested that the heavy metals present in cosmetics do not appear to pose a serious risk to health. However, for heavy users of lip cosmetics, contamination with some heavy metals, such as Pb, Mn, and Cr needs to be minimized.

Evaluation of subchronic exposure to triclosan on hepatorenal and reproductive toxicities in prepubertal male rats

Triclosan (TCS), a common antimicrobial ingredient, is present in many consumer products, including soaps, shampoos, and toothpaste. Owing to its widespread use, potential adverse effects on animals and humans may arise from lifetime exposure, but data on chronic prepubertal exposure of TCS are still lacking. The aim of the present study was to investigate the influence of subchronic TCS exposure (0.25, 25, 250, or 750 mg/kg) on target organ toxicity in prepubertal male rats. After daily administration of TCS to rats by oral gavage for 60 d, a significant reduction in body weight and relative weights of liver, kidneys, testes, and adrenal glands was observed in the 750-mg/kg (high dose) group. Serum alanine aminotransferase and aspartate aminotransferase activities as well as levels of blood urea nitrogen, and creatinine were significantly increased at 750 mg/kg TCS. Further, TCS (750 mg/kg) elevated the protein expressions of hepatic CYP2B1, RXR/PPAR, and levels of malondialdehyde. High-dose TCS exposure induced histological changes as evidenced by reduction of Bowman's space, occlusion of the tubular lumen, and degeneration of tubular epithelial cells in the kidney. Tubular necrosis was confirmed as evidenced by a rise in expression of high mobility group box 1 renal protein. Daily sperm production was significantly diminished by high doses of TCS with marked inhibition of androgen receptor protein expression. Our results indicated that subchronic exposure to excessively high concentrations of 750 mg/kg TCS induced hepatorenal and reproductive toxicities in prepubertal male rats; however, the biological relevance of these findings is questionable as these drug levels are not encountered in the environment.