Vanadium-Induced Testicular Toxicity and Its Prevention by Oral Supplementation of Zinc Sulphate

The association between levels of samarium, hafnium, tungsten and rhenium in seminal plasma and the risk of idiopathic oligo-astheno-teratozoospermia in men of childbearing age

Oligo-astheno-teratozoospermia (OAT) is a global public health problem, which affects 30% men of childbearing age. Meanwhile, with the rapid development of industry and economy, the contents of rare earth elements (REEs) in the environment are increasing. However, little is known about the associations between REEs levels and OAT risk. To evaluate the associations between the levels of four REEs (samarium (Sm), hafnium (Hf), tungsten (W), rhenium (Re)) in seminal plasma and OAT risk, from October 2021 to November 2022, semen samples from 924 men of childbearing age (460 controls and 464 cases) were collected from the reproductive center of the First Affiliated Hospital of Anhui Medical University. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to measure the levels of Sm, Hf, Re and W in seminal plasma. Bayesian kernel machine regression (BKMR) was conducted to explore the joint effects of levels of four REEs in seminal plasma on the risk of OAT and select the one exerting a major role; generalized linear regression models (GLM) with log link function were employed to investigate the association of every REE level in seminal plasma and OAT risk; sankey diagram and linear regression models were utilized to describe the associations between the levels of four REEs and the indexes of sperm quality. The levels of four REEs in seminal plasma were higher in the case group than levels in the control group (pSm = 0.011, pHf = 0.040, pW = 0.062, pRe = 0.001, respectively). In BKMR analysis, the OAT risk increased when the overall levels of four REEs were higher than their 55th percentile compared to all of them at their 50th percentile, and Re level played a major role in the association. Additionally, Re level in seminal plasma was positively associated with  the OAT risk in the single element model after adjustment of covariates (medium vs. low: OR (95% CI) = 1.55 (1.10, 2.18); high vs. low: OR (95% CI) = 1.69 (1.18, 2.42)). Lastly, the sankey diagram and linear regression models revealed that Sm level was negatively associated with the PR%, total sperm count and total progressively motile sperm count; Hf level was negatively associated with the PR%; W and Re levels were negatively associated with the PR% and total motility, and Re level was positively associated with abnormal morphology rate. Men of childbearing age with OAT had higher levels of Sm, Hf and Re in seminal plasma than those in the control group. An increasing trend for the OAT risk was observed with an increase in mixture levels of Sm, Hf, W and Re, and Re exposure level played a major role in the association whether in BKMR model or single element model. Additionally, the levels of these four REEs were negatively associated with the indexes of sperm quality.

Evaluation of immunotoxicity of sodium metavanadate following drinking water exposure in female B6C3F1/N mice in a 28-day study

Sodium metavanadate (NaVO3 ) is a pentavalent vanadium compound used in the metal industry and dietary supplements; human exposure occurs through inhalation of fumes and dust and ingestion of NaVO3 -containing products. The objective of this study was to assess the potential immunotoxicity of NaVO3 . Female B6C3F1/N mice were exposed to 0-500 ppm NaVO3 in drinking water for 28 days and evaluated for effects on immune cell populations and innate, cellular-mediated, and humoral-mediated immunity. There was a decreasing trend in body weight (BW) and BW gain in NaVO3 exposed mice, with a decrease (p ≤ 0.05) in BW gain at ≥250 ppm, relative to control. Conversely, increasing trends in spleen weights and an increase (p ≤ 0.05) in the spleen:BW ratio at ≥250 ppm NaVO3 were observed. NaVO3 exposure altered antibody production against sheep red blood cells (SRBC). Antibody forming cells (AFC)/106 spleen cells exhibited a decreasing trend, with a decrease (p ≤ 0.05) at 500 ppm NaVO3 , concurrent with an increase in percent B cells. NaVO3 had no effect on the serum anti-SRBC IgM antibody titers or anti-keyhole limpet hemocyanin antibody production. Exposure to NaVO3 decreased the percentage of natural killer cells at all dose levels (p ≤ 0.05), with no effect on the lytic activity. NaVO3 altered T-cell populations at 500 ppm but had no effect on T-cell proliferative responses or the lytic activity of cytotoxic T cells. Collectively, these data indicate that NaVO3 exposure can adversely affect the immune system by inducing alterations in humoral-mediated immunity, specifically the AFC response, with no effect on cell-mediated or innate immunity.

Seminal trace elements and their relationship with sperm parameters

Male reproductive problems may derive from many reasons including the environmental toxicants which may either intaken by occupational exposure, nutrition or bad air quality. The increased exposure to these substances due to rapid industrial development and technology has raised the questions: Is there a relationship between sperm parameters and these substances, and if so, in what extent? Results of studies on the subject reported conflicting results, many of which were not investigated in the seminal plasma. The aim of the current study was to evaluate the relationship between 23 metals and trace elements in human seminal plasma and semen parameters many of which were not investigated before. Levels of 23 metals in human seminal plasma were assessed by inductively coupled plasma mass spectrometry (ICP-MS). We examined the differences between subjects with normal ejaculate (normozoospermia) and pathologic ejaculate (with at least one abnormal semen parameter) according to the WHO criteria. The only significant difference was detected for Se while the other element's difference was not statistically significant. Se was statistically significantly increased in normal semen group suggesting the positive effect of this element on semen parameters.

Association between prenatal exposure to metal mixtures and early childhood allergic diseases

The association between prenatal exposure to the metal mixture and allergic diseases is poorly understood. We aimed to explore the individual effect and the combined effect of prenatal exposure to vanadium (V), chromium (Cr), nickel (Ni), arsenic (As), cadmium (Cd), thallium (Tl), and lead (Pb) on early childhood allergic diseases based on a birth cohort study that included 628 mother-infant pairs. Metals were measured in maternal urine samples collected in the first, second, and third trimesters. Children were prospectively followed up at age 4 years to collect information on allergic rhinitis, wheeze, and eczema status. By applying logistic regression models, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR), the different statistical analyses revealed urinary metals were only associated with early childhood allergic rhinitis. The averaged prenatal As exposure was significantly associated with an increased OR for allergic rhinitis in both single-metal (OR = 2.04, 95% CI: 1.35, 3.07) and multiple-metal logistic regression models (OR = 1.78, 95% CI: 1.15, 2.78). The WQS index of mixed metal exposure was positively associated with allergic rhinitis (OR = 1.66, 95% CI: 1.26, 2.19), and As and Tl had the largest weights in the WQS index (weighted 0.51 and 0.29, respectively). The BKMR analysis also showed the overall effect of the metal mixture was significantly associated with allergic rhinitis when all the metals were at their 55th percentile or above, compared to their 50th percentile. The effect of As and Tl on the risk of allergic rhinitis was significant when all of the other metals were fixed at the specific percentiles. Our findings suggest that prenatal co-exposure to higher levels of the seven metals increases the risk of allergic rhinitis in children, and As and Tl may contribute most to the combined risk.

Protective effect of indomethacin on vanadium-induced adrenocortical and testicular damages in rat

Vanadium toxicity is a globally recognized threat to the reproductive health of man and animal. However the mechanism of vanadium-induced damage to the testicular and adrenocortical tissues is not fully characterized. It was hypothesized that prostaglandins may partially mediate the inflammatory response to vanadate damage. In this study prostaglandin (PG) mediated effects of vanadate on testicular and adrenocortical functions was substantiated by using indomethacin to block prostaglandin synthesis. Significant inhibition of spermatogenesis, decreased serum level of testosterone and gonadotropins in the vanadium-exposed group of rats indicated the damaging effects of vanadium-induced reactive oxygen species. This was also reflected in the appreciable increase in testicular lipid peroxidation (LPO) level and decline in the activities of steroidogenic and antioxidant enzymes. Histopathological studies revealed regressive and degenerative changes in testis. However, inhibition of cyclooxygenase activity by indomethacin increased steroid hormone production, gonadotropin level, elevated the specific activities of enzymes and decreased LPO level in rat testis exposed to vanadium. Vanadium also caused prostaglandin mediated adrenocortical hyperactivity, as inhibition of PG synthesis abolished these adrenal responses to vanadium. The studies showed that vanadium toxicity is directly linked to stimulation of prostaglandin synthesis. Therefore, indomethacin can be a good prospect to alleviate vanadium induced male infertility.

Exposure to multiple metals/metalloids and human semen quality: A cross-sectional study

BACKGROUND

Exposure to metals/metalloids, including essential and nonessential elements, has been associated to male reproductive health in animals. However, findings from human studies are inconsistent.

OBJECTIVES

To investigate the impact of exposure to multiple metals/metalloids at environmental levels on the conventional human semen-quality parameters.

MATERIALS AND METHODS

Men living in rural or industrial areas were recruited by personalized letters. No exclusion criteria were applied. Each man provided one semen sample and one blood sample. We analyzed the semen sample both to determine conventional sperm parameters (concentration, progressive motility and normal forms) and to quantify lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), nickel (Ni), vanadium (V) and selenium (Se) levels. The levels of these metals/metalloids were also quantified in venous blood and spermatozoa samples. Associations between the blood/seminal plasma metal/metalloid levels and semen quality parameters were assessed using confounder adjusted logistic regression models. Correlation and interactions between blood/seminal plasma and semen metal/metalloid levels were investigated using the Spearman's correlation.

RESULTS

We found a positive association of seminal plasma cadmium level with lower Total count (OR = 4.48, 95%CI 0.25-80); whereas lead (OR = 4.51, 95%CI 0.86-23) and cadmium (OR = 3.45, 95%CI 0.77-16) seminal plasma levels had a positive association with progressive sperm motility. Overall, these associations remained suggestive after adjustment, though statistically unstable risks. Finally, we found weak interactions between beneficial effects of Se and detrimental ones only for Cd and Pb blood level on sperm concentration, total sperm count and progressive sperm motility.

CONCLUSIONS

Our findings suggest that environmental exposure to Pb and Cd contributes to a decline in human semen quality, whereas Se can have beneficial effects. Measurements of metals/metalloids in the seminal fluid may be more predictable of semen quality than conventional blood measurements.

Correlations between Basal Trace Minerals and Hormones in Middle and Long-Distance High-Level Male Runners

Several essential trace minerals play an important role in the endocrine system; however, toxic trace minerals have a disruptive effect. The aim of this research was to determine basal concentrations and the possible correlations between trace minerals in plasma and several plasma hormones in runners. Sixty high-level male endurance runners (21 ± 3 years; 1.77 ± 0.05 m; 64.97 ± 7.36 kg) participated in the present study. Plasma hormones were analyzed using an enzyme-linked immunosorbent assay (ELISA) and plasma trace minerals were analyzed with inductively coupled plasma mass spectrometry (ICP-MS). Correlations and simple linear regression were used to assess the association between trace minerals and hormones. Plasma testosterone concentrations were inversely correlated with manganese (r = -0.543; β = -0.410; p < 0.01), selenium (r = -0.292; β = -0.024; p < 0.05), vanadium (r = -0.406; β = -1.278; p < 0.01), arsenic (r = -0.336; β = -0.142; p < 0.05), and lead (r = -0.385; β = -0.418; p < 0.01). Plasma luteinizing hormone (LH) levels were positively correlated with arsenic (r = 0.298; β = 0.327; p < 0.05) and cesium (r = 0.305; β = 2.272; p < 0.05), and negatively correlated with vanadium (r = -0.303; β = -2.467; p < 0.05). Moreover, cortisol concentrations showed significant positive correlations with cadmium (r = 0.291; β = 209.01; p < 0.05). Finally, insulin concentrations were inversely related to vanadium (r = -0.359; β = -3.982; p < 0.05). In conclusion, endurance runners living in areas with high environmental levels of toxic minerals should check their concentrations of anabolic hormones.

Protective Effects of Dietary Antioxidants against Vanadium-Induced Toxicity: A Review

Vanadium (V) in its inorganic forms is a toxic metal and a potent environmental and occupational pollutant and has been reported to induce toxic effects in animals and people. In vivo and in vitro data show that high levels of reactive oxygen species are often implicated in vanadium deleterious effects. Since many dietary (exogenous) antioxidants are known to upregulate the intrinsic antioxidant system and ameliorate oxidative stress-related disorders, this review evaluates their effectiveness in the treatment of vanadium-induced toxicity. Collected data, mostly from animal studies, suggest that dietary antioxidants including ascorbic acid, vitamin E, polyphenols, phytosterols, and extracts from medicinal plants can bring a beneficial effect in vanadium toxicity. These findings show potential preventive effects of dietary antioxidants on vanadium-induced oxidative stress, DNA damage, neurotoxicity, testicular toxicity, and kidney damage. The relevant mechanistic insights of these events are discussed. In summary, the results of studies on the role of dietary antioxidants in vanadium toxicology appear encouraging enough to merit further investigations.

Concentrations of vanadium in urine and seminal plasma in relation to semen quality parameters, spermatozoa DNA damage and serum hormone levels

Widespread human exposure to vanadium has been well documented. Vanadium exposure was reported to induce male reproductive toxicity in toxicological studies, yet human epidemiologic studies are lacking. Here we determined the associations between environmental exposure to vanadium and semen quality, spermatozoa DNA damage and serum reproductive hormones. Concentrations of vanadium in seminal plasma and repeated urine samples were determined among 764 men recruited from a reproductive medicine centre. Associations of vanadium concentrations with semen quality parameters (n = 764), DNA integrity measures (n = 404) and serum reproductive hormones (n = 381) were assessed by logistic or linear regression models with adjustment for potential confounders. Significant positive dose-response relationships were observed between vanadium concentrations in seminal plasma and tail length and serum estradiol, as well as odds ratios for a below-reference-value sperm concentration; whereas inverse relationships between seminal plasma vanadium with total testosterone (T) and free T (all p values for trends <0.05) were observed. These relationships were maintained after adjusting for seminal plasma concentrations of other elements (i.e., arsenic, cadmium, copper, selenium, or tin). No significant associations was revealed between urinary vanadium concentrations and semen quality, spermatozoa DNA integrity and reproductive hormones. Our findings suggested that elevated vanadium exposure may be adversely associated with male reproductive health, and that seminal plasma vanadium may be a more direct exposure biomarker for the male reproductive system than urinary vanadium.

Cloud point extraction of vanadium in pharmaceutical formulations, dialysate and parenteral solutions using 8-hydroxyquinoline and nonionic surfactant

A cloud point extraction (CPE) method has been developed for the determination of trace quantity of vanadium ions in pharmaceutical formulations (PF), dialysate (DS) and parenteral solutions (PS). The CPE of vanadium (V) using 8-hydroxyquinoline (oxine) as complexing reagent and mediated by nonionic surfactant (Triton X-114) was investigated. The parameters that affect the extraction efficiency of CPE, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of CPE of V was checked by standard addition method in real samples. The extracted surfactant-rich phase was diluted with nitric acid in ethanol, prior to subjecting electrothermal atomic absorption spectrometry. Under these conditions, the preconcentration of 50 mL sample solutions, allowed raising an enrichment factor of 125-fold. The lower limit of detection obtained under the optimal conditions was 42 ng/L. The proposed method has been successfully applied to the determination of trace quantity of V in various pharmaceutical preparations with satisfactory results. The concentration ranges of V in PF, DS and PS samples were found in the range of 10.5-15.2, 0.65-1.32 and 1.76-6.93 microg/L, respectively.