Effects of vanadate on male rat reproductive tract histology, oxidative stress markers and androgenic enzyme activities

Association of urinary and seminal plasma vanadium concentrations with semen quality: A repeated-measures study of 1135 healthy men

Although animal studies have shown the reproductive toxicity of vanadium, less is known about its effects on semen quality in humans. Among 1135 healthy men who were screened as potential semen donors, we investigated the relationships of semen quality with urinary and seminal plasma vanadium levels via inductively coupled plasma-mass spectrometry (ICP-MS). Spearman rank correlation tests and linear regression models were used to assess the correlations between average urinary and within-individual pooled seminal plasma vanadium concentrations (n = 1135). We utilized linear mixed-effects models to evaluate the associations of urinary and seminal plasma vanadium levels (n = 1135) with repeated sperm quality parameters (n = 5576). Seminal plasma vanadium concentrations were not significantly correlated with urinary vanadium concentrations (r = 0.03). After adjusting for possible confounders, we observed inverse relationships of within-individual pooled seminal plasma vanadium levels with total count, semen volume, and sperm concentration (all P values for trend < 0.05). Specifically, subjects in the highest (vs. lowest) tertile of seminal plasma vanadium concentrations had - 11.3% (-16.4%, -5.9%), - 11.1% (-19.1%, -2.4%), and - 20.9% (-29.0%, -11.8%) lower sperm volume, concentration, and total count, respectively; moreover, urinary vanadium levels appeared to be negatively associated with sperm motility. These relationships showed monotonically decreasing dose-response patterns in the restricted cubic spline analyses. Our results demonstrated a poor correlation between urinary and seminal plasma levels of vanadium, and elevated vanadium concentrations in urine and seminal plasma may be adversely related to male semen quality.

Vanadium administration ameliorates cortical structural and functional changes in juvenile hydrocephalic mice

Vanadium is a prevalent neurotoxic transition metal with therapeutic potentials in some neurological conditions. Hydrocephalus poses a major clinical burden in neurological practice in Africa. Its primary treatment (shunting) has complications, including infection and blockage; alternative drug-based therapies are therefore necessary. This study investigates the function and cytoarchitecture of motor and cerebellar cortices in juvenile hydrocephalic mice following treatment with varying doses of vanadium. Fifty juvenile mice were allocated into five groups (n = 10 each): controls, hydrocephalus-only, low- (0.15 mg/kg), moderate- (0.3 mg/kg), and high- (3.0 mg/kg) dose vanadium groups. Hydrocephalus was induced by the intracisternal injection of kaolin and sodium metavanadate administered by intraperitoneal injection 72hourly for 28 days. Neurobehavioral tests: open field, hanging wire, and pole tests, were carried out to assess locomotion, muscular strength, and motor coordination, respectively. The cerebral motor and the cerebellar cortices were processed for cresyl violet staining and immunohistochemistry for neurons (NeuN) and astrocytes (glial fibrillary acidic protein). Hydrocephalic mice exhibited body weight loss and behavioral deficits. Horizontal and vertical movements and latency to fall from hanging wire were significantly reduced, while latency to turn and descend the pole were prolonged in hydrocephalic mice, suggesting impaired motor ability; this was improved in vanadium-treated mice. Increased neuronal count, pyknotic cells, neurodegeneration and reactive astrogliosis were observed in the hydrocephalic mice. These were mostly mitigated in the vanadium-treated mice, except in the high-dose group where astrogliosis persisted. These results demonstrate a neuroprotective potential of vanadium administration in hydrocephalus. The molecular basis of these effects needs further exploration.

Vanadium and biomarkers of inflammation and oxidative stress in diabetes: A systematic review of animal studies

Background: Oxidative stress has a significant role in the commencement and development of hyperglycemia. Vanadium, as a transitional metal with redox properties, enters the redox process, produces free radicals, and distracts the pro-antioxidant balance. The present animal systematic review aimed to assess the effect of vanadium supplementation on inflammation and oxidative stress biomarkers in diabetes-induced animals. Methods: A systematic search was conducted using the PubMed, Scopus, and web of science databases from 1990 to 2021, according to the inclusion and exclusion criteria. The search strategy was based on the guidelines for systematic review of animal experiments and Preferred Reporting Items for Systematic Reviews (PRISMA). Criteria for eligibility were animal-based studies, evaluating the therapeutic effects of vanadium on inflammatory and oxidative stress biomarkers in diabetes. The Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool was used for assessing the methodological quality of included studies. Results: In the present study, 341 articles were evaluated out of which 42 studies were eligible for inclusion. The majority of the studies confirmed the advantageous properties of vanadium on inflammatory and oxidative stress biomarkers. A minor risk of bias was reported, based on the SYRCLE's tool. Conclusion: According to the findings, well-designed clinical trials are warranted to assess the long-lasting effects of various vanadium compounds on inflammatory and oxidative stress biomarkers.

Low-level and combined exposure to environmental metal elements affects male reproductive outcomes: Prospective MARHCS study in population of college students in Chongqing, China

BACKGROUND

Male fertility has shown a continuously declining tendency for decades. Over exposure to metal/metalloid elements has been proposed as associated with reproductive impairment. However, the hazard profile remained unclear in general public experiencing low-level and combined metal exposure.

METHODS

Based on the MARHCS cohort in Chongqing, China, 796 college students were recruited from June 2013 and 666 subjects were followed up next year. At each phase, semen and blood samples were collected for an assessment of semen quality and six sex hormones levels. Eighteen urinary metal/metalloid elements were quantified by ICP-MS as internal exposure biomarkers. Cluster analysis was conducted to characterize reproductive outcomes in the subgroups for different overall estimated exposure levels. Effects of each metal/metalloid element were analyzed using multiple statistical strategies: single-element mixed model, multiple-elements model and self before-after comparison design.

RESULTS

The urine concentration for 18 metal/metalloid elements was at a typically lower level (far away from the exposure limits) and positively associated with each other. After adjustment of the potential confounders, a decrease of 11.53% (95% CI: -18.61, -3.84%) and 10.84% (95% CI: -17.93, -3.14%) in spermatid morphology was observed in the highest quantile groups of vanadium (V) and nickel (Ni), respectively. Urinary silver (Ag) was dose-dependent associated with an increase in total sperm number (6.91%, 95% CI: 1.14, 13.00%), sperm concentration (16.38%, 95% CI: 5.15, 28.81%) and semen volume (23.73%, 95% CI: 10.46, 38.60%). Further, hormone testosterone presented a significant decrease in subgroup with higher overall estimated exposure and a stable negative association with lithium (Li). The above relationships remained significant across different statistical strategies (all p values <0.05).

CONCLUSION

Our study provided new evidences that exposure to metal/metalloid elements potentially exert bidirectional influences on semen quality at a relatively low level. And serum testosterone appears as a vulnerable index for metal exposure.

Beneficial effects of Salvia officinalis essential oil on vanadium-induced testicular injury, DNA damage and histological alterations in Wistar rats

Vanadium has been shown to catalyze the generation of reactive oxygen species. Since free radical production and lipid peroxidation are potentially important mediators in testicular physiology and pathophysiology, the present study was conducted to elucidate vanadium-induced oxidative damage in rat testis and the ameliorative role of Salvia officinalis essential oil (SEO) against the adverse effects of this heavy metal. Adult male Wistar rats were treated daily during 10 days either with ammonium metavanadate (5 mg/kg bw, intraperitoneally), SEO (15 mg/kg bw, orally) or their combination. A group of rats receiving daily a saline solution served as a negative control. Vanadium treatment induced a significant decrease in body and reproductive organ weights, serum testosterone level and sperm number and motility. An increase in lipid peroxidation and protein oxidation as well as a marked inhibition in the activities of antioxidant enzymes in the testes and seminal vesicles indicated the occurrence of oxidative stress after vanadium toxicity. Histopathological changes in testis and seminal vesicles were also observed following vanadium administration. However, co-administration of SEO to vanadium-treated rats resulted in an appreciable improvement of these parameters, emphasizing the therapeutic effects of SEO. It can be suggested that SEO mitigates vanadium-induced reproductive damage due to its antioxidant capacity. Thus, we can hypothesize that SEO supplementation could protect against vanadium poisoning.

High doses of catecholamines activate glucose transport in human adipocytes independently from adrenoceptor stimulation or vanadium addition

BACKGROUND

When combined with vanadium salts, catecholamines strongly activate glucose uptake in rat and mouse adipocytes.

AIM

To test whether catecholamines activate glucose transport in human adipocytes.

METHODS

The uptake of 2-deoxyglucose (2-DG) was measured in adipocytes isolated from pieces of abdominal subcutaneous tissue removed from women undergoing reconstructive surgery. Pharmacological approaches with amine oxidase inhibitors, adrenoreceptor agonists and antioxidants were performed to unravel the mechanisms of action of noradrenaline or adrenaline (also named epinephrine).

RESULTS

In human adipocytes, 45-min incubation with 100 µmol/L adrenaline or noradrenaline activated 2-DG uptake up to more than one-third of the maximal response to insulin. This stimulation was not reproduced with millimolar doses of dopamine or serotonin and was not enhanced by addition of vanadate to the incubation medium. Among various natural amines and adrenergic agonists tested, no other molecule was more efficient than adrenaline and noradrenaline in stimulating 2-DG uptake. The effect of the catecholamines was not impaired by pargyline and semicarbazide, contrarily to that of benzylamine or methylamine, which are recognized substrates of semicarbazide-sensitive amine oxidase. Hydrogen peroxide at 1 mmol/L activated hexose uptake but not pyrocatechol or benzoquinone, and only the former was potentiated by vanadate. Catalase and the phosphoinositide 3-kinase inhibitor wortmannin inhibited adrenaline-induced activation of 2-DG uptake.

CONCLUSION

High doses of catecholamines exert insulin-like actions on glucose transport in human adipocytes. At submillimolar doses, vanadium did not enhance this catecholamine activation of glucose transport. Consequently, this dismantles our previous suggestion to combine the metal ion with catecholamines to improve the benefit/risk ratio of vanadium-based antidiabetic approaches.

Beyond the mean: Quantile regression to differentiate the distributional effects of ambient PM2.5 constituents on sperm quality among men

Ambient PM_2.5 (particulate matter ≤ 2.5 μm in aerodynamic diameter) constituents have been related to mean changes in semen quality, but focusing on the mean response may not well capture distributional and heterogeneous effects of PM_2.5 constituents on semen quality. In this study, 2314 semen samples of 622 men between Jan 1, 2019 and Dec 31, 2019 from Guangdong Human Sperm Bank were subjected to semen quality analysis. Daily average concentrations of PM_2.5 constituents including 4 water-soluble ions and 15 metals/metalloid were measured for 7 days per month at 3 fixed atmospheric pollutant monitoring stations. We used quantile regression for longitudinal data to examine whether the associations between PM_2.5 constituents and quality indicators of semen varied across quantiles of outcome distribution. Heterogeneous associations were found between PM_2.5 constituents and sperm quality across different quantiles. An interquartile range (14.0 μg/m³) increase in PM_2.5 mass was negatively associated with lower tails of sperm concentration and upper tails of sperm count distribution. PM_2.5 vanadium exposure was significantly related to the 90th percentile of sperm count distribution, but not to the lower quantiles. In addition, those subjects with relatively high sperm motility were more susceptible to sulfate, chromium, and manganese constituents in PM_2.5. Our results indicate that PM_2.5 and certain constituents were associated with sperm quality, especially sperm motility, and the associations are more pronounced in men with relatively high or low sperm motility.

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.

Anti-oxidant and hepatoprotective effects of Salvia officinalis essential oil against vanadium-induced oxidative stress and histological changes in the rat liver

The present study was designed to evaluate the protective effects of Salvia officinalis essential oil (SOEO) against vanadium-induced hepatotoxicity in Wistar rats. Animals were divided into three groups: the first group served as the control (C), where rats received daily 0.5 mL of saline solution (0.9%) given by intraperitoneal (i.p.) way. Rats in the second group (V) received daily by i.p. way 5 mg/kg BW of NH₄VO₃ (V). Rats in the third group (SV) received daily V (5 mg/kg BW) by i.p. way and SOEO (15 mg/kg BW) by gavage. Animals were sacrificed after 4 or 10 days of treatment. Administration of V increased plasma ALT, AST, ALP, and LDH activities, and cholesterol, bilirubin, triglyceride, and NO levels in rats and reduced anti-oxidant enzyme activities in the liver. Treatment with SOEO significantly attenuated these changes. Moreover, the histopathological changes and the overexpression of Hsp72/73 proteins induced by V were significantly improved by SOEO. Therefore, our results suggested that SOEO could protect against V-induced oxidative damage in rat livers. The hepatoprotective effect of SOEO might be attributed to its modulation of detoxification enzymes and/or to its anti-oxidant and free radical scavenging effects.

Age-Related Effects of Orthovanadate Nanoparticles Involve Activation of GSH-Dependent Antioxidant System in Liver Mitochondria

Vanadium is an important ultra-trace element nowadays attracting attention with particular emphasis on medical application. But the therapeutic application of vanadium-based drugs is still questionable and restricted due to some toxic side effects. It was found that unique redox properties of vanadium in nanoform provided antioxidant activity and prevented oxidative disturbance in cells in vitro. Though, on the organism level, ambiguous effects of vanadium-based nanoparticles were observed. In this study, the age-related features of prooxidant/antioxidant balance in blood serum and liver mitochondrial and postmitochondrial fractions of 3 and 18-month-old Wistar male rats treated with orthovanadate nanoparticles (GdVO₄/Eu³⁺, 8 × 25 nm) within 2 months have been investigated. Prooxidant potential-related indexes were the content of lipid hydroperoxides as well as aconitase activity. Activity of glutathione peroxidase, glutathione-S-transferase, glutaredoxin, glutathione reductase, glucose-6-phosphate dehydrogenase, and NADPH-dependent isocitrate dehydrogenase designated the tissue antioxidant potential. Based on the obtained values, the integral index of the prooxidant/antioxidant balance-the reliability coefficient (Kr) has been calculated. The data show that due to activation some chain links of GSH-dependent antioxidant system, GdVO₄/Eu³⁺ nanoparticles increase the reliability of the prooxidant-antioxidant balance in tissues and especially in the liver mitochondria of old animals (Kr in mitochondria of young rats was 2.94, and in mitochondria of old ones-9.83 conventional units). Detected in vitro glutathione peroxidase-like activity of the GdVO₄/Eu³⁺ nanoparticles is supposed to be among factors increasing the reliability of the system. So, for the first time, the beneficial effect of the long-term orthovanadate nanoparticle consumption in old males has been discovered.

Cichorium intybus L. extract ameliorates testicular oxidative stress induced by lead acetate in male rats

Objective

Oxidative stress has been suggested as a possible mechanism for the adverse effects of heavy metal toxicity on male reproduction. Cichorium intybus L. is used in Iranian folk medicine as a hepatoprotective agent as well as for its supposed fertility-enhancing properties. The present study was performed to investigate whether the ethanolic extract of C. intybus leaves could protect male rats against lead-induced testicular oxidative stress.

Methods

In this experimental study, adult Wistar rats were treated with 0.1% lead acetate in drinking water alone or with 50, 100, or 200 mg/ kg body weight of C. intybus extract via gavage once daily for 70 days. The weight of their reproductive organs, levels of serum hormones, histometric parameters of the seminiferous tubules, epidydimal sperm quality, and oxidative stress status were evaluated.

Results

The testis weight, seminiferous tubule diameter, epididymal sperm count, serum testosterone level, and testicular levels of superoxide dismutase and glutathione peroxidase were significantly reduced (p<0.05) in the lead-treated rats. Moreover, significantly (p<0.05) higher levels of malondialdehyde were observed in the lead-exposed group compared to the control. However, the co-administration of C. intybus ethanolic extract in lead-treated rats was associated with a significant improvement in reproductive parameters.

Conclusion

We conclude that C. intybus leaf extract has the potential to prevent lead-induced testicular toxicity and to suppress the adverse effects of lead on male reproductive health.

Vanadium adversely affects sperm motility and capacitation status via protein kinase A activity and tyrosine phosphorylation

Vanadium is a chemical element that enters the atmosphere via anthropogenic pollution. Exposure to vanadium affects cancer development and can result in toxic effects. Multiple studies have focused on vanadium's detrimental effect on male reproduction using conventional sperm analysis techniques. This study focused on vanadium's effect on spermatozoa following capacitation at the molecular level, in order to provide a more detailed assessment of vanadium's reproductive toxicity. We observed a decrease in germ cell density and a structural collapse of the testicular organ in seminiferous tubules during vanadium treatment. In addition, various sperm motion parameters were significantly decreased regardless of capacitation status, including sperm motility, rapid sperm motility, and progressive sperm motility. Curvilinear velocity, straight-line velocity, average path velocity, beat cross frequency, and mean amplitude of head lateral displacement were also decreased after capacitation. Capacitation status was altered after capacitation. Vanadium dramatically enhanced protein kinase A (PKA) activity and tyrosine phosphorylation. Taken together, our results suggest that vanadium is detrimental to male fertility by negatively influencing sperm motility, motion kinematics, and capacitation status via abnormal PKA activity and tyrosine phosphorylation before and after capacitation.

Vanadium and Oxidative Stress Markers - In Vivo Model: A Review

This review article is an attempt to summarize the current state of knowledge of the impact of Vanadium (V) on Oxidative Stress (OS) markers in vivo. It shows the results of our studies and studies conducted by other researchers on the influence of different V compounds on the level of selected Reactive Oxygen Species (ROS)/Free Radicals (FRs), markers of Lipid peroxidation (LPO), as well as enzymatic and non-enzymatic antioxidants. It also presents the impact of ROS/peroxides on the activity of antioxidant enzymes modulated by V and illustrates the mechanisms of the inactivation thereof caused by this metal and reactive oxygen metabolites. It also focuses on the mechanisms of interaction of V with some nonenzymatic compounds of the antioxidative system. Furthermore, we review the routes of generation of oxygen-derived FRs and non-radical oxygen derivatives (in which V is involved) as well as the consequences of FR-mediated LPO (induced by this metal) together with the negative/ positive effects of LPO products. A brief description of the localization and function of some antioxidant enzymes and low-molecular-weight antioxidants, which are able to form complexes with V and play a crucial role in the metabolism of this element, is presented as well. The report also shows the OS historical background and OS markers (determined in animals under V treatment) on a timeline, collects data on interactions of V with one of the elements with antioxidant potential, and highlights the necessity and desirability of conducting studies of mutual interactions between V and antioxidant elements.

Beneficial effects of Cichorium intybus L. extract on oxidative status and reproductive parameters in male Wistar rats: An experimental study

Background

During recent years, increasing concern has been raised about the declining sperm count and human male infertility. Cichorium intybus L. (C. intybus) has traditionally been used in Iranian folk medicine as hepato protective and blood purifier and for its presumed fertility-enhancing properties.

Objective

A dose-response study was performed to determine the effect of C. intybus ethanolic leave extract on the reproductive parameters in adult Wistar male rats.

Materials and Methods

In this experimental study, 40 healthy adult male Wistar rats (8 wk old, 200-210 gr body weight) were randomly divided (n = 10/each) as control and groups treated with 50, 100, and 200 mg/kg/day of C. intybus extract via gavage for 70 days. Serum hormonal assay, epididymal sperm evaluation, and analysis of morphometrical parameters, antioxidant enzymes, and lipid peroxidation levels of testis were done in each experimental group.

Results

Weights of testis and epididymis increase significantly in male rats treated with 200 mg/kg C. intybus extract. Sperm density and percent of morphologically normal sperm were significantly increased in a dose-related manner with C. intybus treatment.Serum testosterone was higher at 100 and 200 mg/kg C. intybus extract-treated groups. C. intybus significantly reduced malondialdehyde levels and also increased superoxide dismutase and glutathione peroxidase activity in testicular tissue of rats.

Conclusion

It is concluded that C. intybus leave extract improves reproductive parameters in male rats which might be a consequence of both its antioxidant and androgenic properties.

Oral administration of ammonium metavanadate and potassium dichromate distorts the inflammatory reaction induced by turpentine oil injection in male rats

Heavy metal pollution is rapidly increasing in the environment. It has been shown that exposure to vanadium and chromium is able to alter the immune response. Nevertheless, the mechanisms by which these metal pollutants mediate their immunomodulatory effects are not completely understood. Herein, we examined the effect of ammonium metavanadate and potassium dichromate on the development of an inflammatory response caused by subcutaneous injection of turpentine oil. We demonstrated that pretreatment of rats with ammonium metavanadate and potassium dichromate for two weeks prior to initiation of the inflammatory response resulted in a wider zone of necrosis surrounding the site of inflammation. The acute inflammatory process in the combined model was characterized by elevated serum levels of IL-10 and decreased serum levels of IL-6 as compared to rats not treated with ammonium metavanadate and potassium dichromate. Ammonium metavanadate and potassium dichromate administration induced a decrease in the proportion of splenic His48^HighCD11b/c⁺ myeloid cells accompanied by a reduced infiltration of the wound with neutrophils. Further analysis showed decreased proportions of CD3⁺CD4⁺IFNγ⁺ and CD3⁺CD4⁺IL-4⁺ T cells in the rats with combined model as compared to inflamed rats not treated with ammonium metavanadate and potassium dichromate. The data suggest that consumption of vanadium and chromium compounds disrupts the inflammatory response through an altered balance of pro- and anti-inflammatory cytokines and inhibition of effector T cell activation and neutrophil expansion.

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.

[6]-Gingerol modulates spermatotoxicity associated with ulcerative colitis and benzo[a]pyrene exposure in BALB/c mice

BACKGROUND

The deterioration of male reproductive health may represent an outcome of an active disease and environmental factors. The present study investigated the modulatory role of [6]-gingerol in spermatotoxicity resulting from colitis and benzo[a]pyrene (B[a]P), an environmental and food-borne pollutant.

METHODS

Group I (control) mice received corn oil alone, while group II ([6]-gingerol alone) mice orally received [6]-gingerol alone at 100 mg/kg body weight. Group III [benzo[a]pyrene+dextran sulfate sodium (BDS) alone] mice were orally exposed to B[a]P at 125 mg/kg for 7 days followed by three cycles of 4% dextran sulfate sodium (DSS) in drinking water. A cycle consisted of seven consecutive days of exposure to DSS-treated water followed by 14 consecutive days of normal drinking water. Group IV (BDS+[6]-gingerol) mice were orally treated daily with 100 mg/kg of [6]-gingerol during exposure to B[a]P and DSS in the same manner as those of group III.

RESULTS

[6]-Gingerol significantly abrogated BDS-mediated increase in disease activity index and restored the colon wet weight, colon length and colon mass index to near normal when compared to BDS alone group. Moreover, [6]-gingerol significantly prevented BDS-induced decreases in the daily sperm production (DSP), testicular sperm number (TSN), epididymal sperm number, sperm progressive motility and sperm membrane integrity when compared with the control. [6]-Gingerol markedly increased the sperm antioxidant enzymes activities and decreased the sperm head, mid-piece and tail abnormalities as well as suppressed oxidative stress and inflammatory biomarkers in BDS-exposed mice.

CONCLUSIONS

[6]-Gingerol protected against spermatotoxicity in experimental model of interaction of colitis with environmental pollutant B[a]P.

Taurine reverses sodium fluoride-mediated increase in inflammation, caspase-3 activity, and oxidative damage along the brain-pituitary-gonadal axis in male rats

Excessive exposure to fluoride is associated with male reproductive dysfunction in humans and animals. Taurine (2-aminoethane sulfonic acid) is a free intracellular β-amino acid with antioxidant, anti-inflammatory, and neuroprotective properties. However, the effect of taurine on fluoride-induced reproductive toxicity has not been reported. The present study investigated the influence of taurine on sodium fluoride (NaF)-induced functional changes along the brain-pituitary-gonadal axis in male rats. NaF was administered singly in drinking water at 15 mg·L^-1 alone or orally co-administered by gavage with taurine at 100 and 200 mg·(kg body mass)^-1 for 45 consecutive days. Results showed that taurine significantly prevented NaF-induced increase in oxidative stress indices as well as augmented antioxidant enzymes activities and glutathione level in the brain, testes, and epididymis of the treated rats. Moreover, taurine reversed NaF-induced elevation in inflammatory biomarkers and caspase-3 activity as well as histological damage in the brain, testes, and epididymis of the treated rats. The significant reversal of NaF-induced decreases in testosterone level and testicular activities of acid phosphatase, alkaline phosphatase, and lactate dehydrogenase by taurine was accompanied by enhancement of sperm functional characteristics in the treated rats. Taurine may be a possible chemopreventive candidate against reproductive dysfunction resulting from fluoride exposure.

iTRAQ-based proteomic technology revealed protein perturbations in intestinal mucosa from manganese exposure in rat models

Manganese (Mn) is an essential metal ion as a biological cofactor, but in excess, it is toxic; however, the homeostatic mechanisms of Mn at the cellular level have not been identified.

Effect of Excess Iodine on Oxidative Stress Markers, Steroidogenic-Enzyme Activities, Testicular Morphology, and Functions in Adult Male Rats

Improper iodine intake is a major concern in public health. Chronic intake of low iodine affects gonadal functions of man and animals; however, such effects of excess iodine in male reproduction, specially on testicular morphology, testicular steroidogenic enzyme activities, sperm morphology, sperm viability, and sperm count including male hormonal profiles in reference to iodine status and thyroid hormone profiles are yet to be explored. With this background, adult male rats of 120 ± 10 gm Bw of 90 ± 5 days were divided broadly in two groups depending on the duration of the treatment for 30 and 60 days, respectively. Both the groups consisted of control animals. Excess iodine (100EI), i.e., 100 times more than its recommended level but within its tolerable ranges, was administered through gavage regularly to the first group of experimental animals for 30 and 60 days, respectively, and excessive iodine (500EI), i.e., 500 times more than its recommended level and above tolerable range in the same way and for the same durations, was administered to the other group of experimental animals. Overall results revealed that regular consumption of iodine in excess impairs reproductive functions in adult male rats depending on the dose and duration of its exposure through different mechanisms. Excess iodine accumulates in the testis which results in generation of reactive oxygen species (ROS) as evidenced by higher lipid peroxidation level as well as an imbalance in the pro-/antioxidant status inhibiting the activity of ∆(5) 3β- hydroxysteroid dehydrogenase (HSD) and 17β-HSD resulting to reduced synthesis of testosterone that causes structural and functional changes of the testis. Secondly, persistent generation of ROS in testis as a result of prolonged excess iodine exposure affects hypothalamo-pituitary-adrenal axis that stimulates synthesis and secretion of corticosterone which inhibits LH release that downregulates testosterone synthesis causing further testicular disruption. Thirdly, excess iodine when administered above its tolerable ranges for prolonged duration acts on thyroid itself developing a state of biochemical hypothyroidism (as evident by low T3) which further potentiate the disrupting effect of excess iodine on male gonads by reducing circulating testosterone level.

A review of metal-catalyzed molecular damage: protection by melatonin

Metal exposure is associated with several toxic effects; herein, we review the toxicity mechanisms of cadmium, mercury, arsenic, lead, aluminum, chromium, iron, copper, nickel, cobalt, vanadium, and molybdenum as these processes relate to free radical generation. Free radicals can be generated in cells due to a wide variety of exogenous and endogenous processes, causing modifications in DNA bases, enhancing lipid peroxidation, and altering calcium and sulfhydryl homeostasis. Melatonin, an ubiquitous and pleiotropic molecule, exerts efficient protection against oxidative stress and ameliorates oxidative/nitrosative damage by a variety of mechanisms. Also, melatonin has a chelating property which may contribute in reducing metal-induced toxicity as we postulate here. The aim of this review was to highlight the protective role of melatonin in counteracting metal-induced free radical generation. Understanding the physicochemical insights of melatonin related to the free radical scavenging activity and the stimulation of antioxidative enzymes is of critical importance for the development of novel therapeutic strategies against the toxic action of these metals.

Testicular Mineralization in KK-A(y) Mice Treated with an Oxovanadium Complex

Vanadium has potential for use in diabetes therapy. Many investigators have reported toxic effects of inorganic vanadium salts; however, there are few reports on toxic effects of oxovanadium(VO²⁺) complexes. Therefore, we studied VO²⁺ toxicity by examining histological changes and measuring the vanadium concentration in the testis after repeated oral administration of bis(1-oxy-2-pyridine-thiolato)oxovanadium(VO²⁺) (VO(opt)₂) for 2 or 4 weeks in KK-A^y mice. Severe mineralization and degeneration/necrosis of the seminiferous tubules were detected after either 2 or 4 weeks of administration. Vacuolar changes in Sertoli cells and the seminiferous epithelia, and hyperplasia of Leydig cells were observed in the testes of some animals. Vanadium concentrations in the mineralized testis were much higher than those in the testis of untreated KK-A^y mice. These results represent the first report of the possibility for seminiferous tubules mineralization induced by VO(opt)₂ administration. Therefore, our research provides important information about the potentially toxic effects of VO²⁺ complexes.

Vanadium inhalation induces actin changes in mice testicular cells

Infertility is becoming a health problem, which has increased mainly in megacities, and several studies have shown its association with environmental pollution. Air pollution has been linked to alterations in sperm parameters, both in humans and animal models. In male humans, it has been associated with reduced semen quality and DNA alterations. Vanadium is a transition element that has increased in recent decades as a component of air suspended matter and has been associated with reprotoxic effects in animal models. Few are the mechanisms described by which the vanadium produces these effects, and cytoskeleton interaction is a possibility. We reported immunohistochemical changes in actin testicular cytoskeleton in a vanadium inhalation experimental mice model. Our findings show that exposure to vanadium pentoxide (0.02 M) results in actin decrease in testicular cells from 3-12 weeks exposure time; this effect was statistically significant and exposure time dependent. Actin cytoskeleton damage is a mechanism that could explain vanadium reprotoxic effects and its association with impaired fertility.

Methoxychlor induced biochemical alterations and disruption of spermatogenesis in adult rats

Adult male albino rats were treated orally with methoxychlor at doses of 0, 50, 100 or 200 mg/kg/day for 15 consecutive days. Testicular weight, sperm count and motility were significantly decreased. Methoxychlor at doses of 100 and 200 mg/kg significantly inhibited α-glucosidase activity, while plasma testosterone was significantly decrease by the three dose levels in a dose-related pattern. Testicular activities of 3β-HSD, 17β-HSD, SDH were significantly decreased, while ACP, ALP (except for 50 mg/kg), and LDH were significantly increased. H2O2 production and LPO were significantly increased while the enzymic (SOD, CAT and GPx) and non-enzymic antioxidants (thiol content) were significantly decreased. Caspase-3 activity was significantly increased in a dose related manner. The findings of this study indicate that methoxychlor induces oxidative stress associated with impairment of spermatogenesis, in addition to apoptosis. These data provide insight into the mode of action of methoxychlor-induced toxicity in the rat testis.

Protective effects of Fumaria parviflora L. on lead-induced testicular toxicity in male rats

In recent years, the clinical importance of herbal drugs has received considerable attention in reducing free radical-induced tissue injury. Oxidative stress has been proposed as a possible mechanism involved in lead toxicity that causes reproductive system failure in both human and animals. Fumaria parviflora L., a traditional herb, has been used to cure various ailments in Persian folk medicine. This study was carried out to investigate whether ethanolic extract of F. parviflora leaves could protect the male rats against lead-induced testicular oxidative stress. Adult Wistar rats were treated with 0.1% lead acetate in drinking water with or without 200 mg kg day(-1) F. parviflora extract via gavage for 70 days. Lead acetate treatment resulted in significant reduction in testis weight, seminiferous tubules diameter, epididymal sperm count, serum testosterone level, testicular content of superoxide dismutase (SOD) and glutathione peroxidase (GPx). Moreover, significant elevation was observed in content of malondialdehyde (MDA) in lead-treated rats. However, co-administration of F. parviflora extract showed a significant increase in selected reproductive parameters in lead-treated rats. The results indicated that ethanolic extract of F. parviflora leaves has a potential to restore the suppressed reproduction associated with lead exposure and prevented lead-induced testicular toxicity in male Wistar rats.

Maternal caffeine consumption has irreversible effects on reproductive parameters and fertility in male offspring rats

OBJECTIVE

Concerns are growing about the decrease in male reproductive health. Caffeine is one of the popular nutrients that has been implicated as a risk factor for infertility. In the present study, we examined whether in utero and lactational exposure to caffeine affects the reproductive function of the offspring of rats.

METHODS

Pregnant rats received caffeine via drinking water during gestation (26 and 45 mg/kg) and lactation (25 and 35 mg/kg). Body and reproductive organ weight, seminiferous tubule diameter, germinal epithelium height, sperm parameters, fertility rate, number of implantations, and testosterone level of the offspring were assessed from birth to adulthood.

RESULTS

Significant dose-related decreases were observed in the body and reproductive organ weight, seminiferous tubule diameter, and germinal epithelium height of the offspring. Sperm density had declined significantly in offspring of the low-dose and high-dose groups, by 8.81% and 19.97%, respectively, by postnatal day 150. The number of viable fetuses had decreased significantly in females mated with male offspring of the high-dose group at postnatal days 60, 90, 120, and 150. There were also significant reductions in testosterone levels of high-dose group offspring from birth to postnatal day 150.

CONCLUSION

It is concluded that maternal caffeine consumption impairs gonadal development and has long-term adverse effects on the reproductive efficiency of male offspring rats.

Dietary calcium induced cytological and biochemical changes in thyroid

Certain epidemiological studies revealed correlation between hard water consumption (with high calcium) and thyroid size of the population, though the possible alterations in thyroid physiology upon calcium exposure are still inconclusive. Adult male Wistar strain rats were subjected to calcium treatment at the doses of 0.5g%, 1.0g% and 1.5g% calcium chloride (CaCl(2)) for 60 days. The parameters studied were - thyroid gland weight, histopathology, histomorphometry; thyroid peroxidase (TPO), 5'-deiodinase I (DI), sodium-potassium adenosine triphosphatase (Na(+)-K(+)-ATPase) activities; serum total and free thyroxine (tT4, fT4), total and free triiodothyronine (tT3, fT3), thyroid stimulating hormone (TSH) levels. Enlargement of thyroid with hypertrophic and hyperplastic changes, retarded TPO and 5'-DI but enhanced Na(+)-K(+)-ATPase activities, augmented serum total and free T4 and TSH but decreased total and free T3 levels and low T3/T4 ratio (T3:T4) were observed in the treated groups. All these findings indicate development of goitrogenesis upon exposure to excessive dietary calcium.

Excessive dietary calcium in the disruption of structural and functional status of adult male reproductive system in rat with possible mechanism

Calcium is essential for functioning of different systems including male reproduction. However, it has also been reported as chemo-castrative agent. The study has been undertaken to elucidate the effect of excessive dietary calcium on male reproductive system in animals with possible action. Adult male healthy rats fed CaCl(2) at different doses (0.5, 1.0 and 1.5 g%) in diet for 13 and 26 days to investigate reproductive parameters as well as the markers of oxidative stress. Significant alteration was found (P < 0.05) in testicular and accessory sex organs weight, epididymal sperm count, testicular steroidogenic enzyme (Δ(5) 3β-HSD and 17β-HSD) activities, serum testosterone, LH, FSH, LPO, activities of antioxidant enzymes, testicular histoarchitecture along with adrenal Δ(5) 3β-HSD activity with corticosterone level in dose- and time-dependent manner. Overall observations suggest that excessive dietary calcium enhances the generation of free-radicals resulting in structural and functional disruption of male reproduction.

Impact of vanadium complexes treatment on the oxidative stress factors in wistar rats plasma

The aim of this study was to investigate the clinical efficacy of vanadium complexes on triglycerides (TG), total cholesterol (Chol), uric acid (UA), urea (U), and antioxidant parameters: nonenzymatic (FRAP—ferric reducing ability of plasma, and reduced glutathione—GSH) and enzymatic (glutathione peroxidase—GPx, catalase—CAT, and GPx/CAT ratio) activity in the plasma of healthy male Wistar rats. Three vanadium complexes: [VO(bpy)₂]SO₄·2H₂O, [VO(4,4′Me₂bpy)₂]SO₄·2H₂O, and Na[VO(O₂)₂(bpy)]·8H₂O are administered by gavage during 5 weeks in two different diets such as control (C) and high fatty (F) diets. Changes of biochemical and antioxidants parameters are measured in plasma. All three vanadium complexes statistically decrease the body mass growth in comparison to the control and fatty diet. In plasma GSH was statistically increased in all vanadium complexes-treated rats from control and fatty group in comparison to only control group. Calculated GPX/CAT ratio was the highest in the control group in comparison to others.

Vanadium inhalation in a mouse model for the understanding of air-suspended particle systemic repercussion

There is an increased concern about the health effects that air-suspended particles have on human health which have been dissected in animal models. Using CD-1 mouse, we explore the effects that vanadium inhalation produce in different tissues and organs. Our findings support the systemic effects of air pollution. In this paper, we describe our findings in different organs in our conditions and contrast our results with the literature.

Effects of combined vanadate and magnesium treatment on erythrocyte antioxidant defence system in rats

The effect of vanadate and magnesium treatment on erythrocyte defence system was studied in outbred 2-month-old, albino male Wistar rats (14 rats/each group) which daily received: Group I (Control)-deionized water to drink; Group II-water solution of sodium metavanadate (NaVO(3); SMV) at a concentration of 0.125mgV/mL; Group III-water solution of magnesium sulfate (MgSO(4); MS) at a concentration of 0.06mgMg/mL, Group IV-water solution of SMV-MS at the same concentrations over a 12-week time. The fluid intake and the concentration of reduced glutathione (GSH) as well as the activity of Cu, Zn-superoxide dismutase (Cu, Zn-SOD), catalase (CAT) and glutathione reductase (GR) were significantly decreased in the rats receiving SMV alone (Group II) or in combination with MS (Group IV) compared with Groups I and III. The cellular glutathione peroxidase (cGSH-Px) activity was unchanged in all the treated groups. The activity of glutathione S-transferase (GST) fell in the animals in Group II, compared with the rats in Groups I, III and IV; whereas in the rats in Group III its activity was higher than in the control animals. These results showed that V (as SMV) consumed by the rats with drinking water at a dose of 12mgV/kg b.w./24h for 12 weeks may attenuate defence system in rats' erythrocytes (RBCs), which is probably a consequence of vanadium pro-oxidant potential. Therefore, reactive oxygen species (ROS) are suggested to be involved in the alterations in antioxidant defence system in these cells. Mg (as MS) at the dose ingested (6mgMg/kg b.w./24h) at co-exposure to SMV was not able to counteract its deleterious effect. The results also provide evidence that V-Mg interactions may be involved in the decrease of erythrocyte GR activity and Mg concentration in the plasma under concomitant treatment with both metals at the doses of 12.6mgV and 6mgMg/kg b.w./24h.

Effect of different doses of un-fractionated green and black tea extracts on thyroid physiology

Tea is a rich source of polyphenolic flavonoids including catechins, which are thought to contribute to the health benefits of it. Flavonoids have been reported to have antithyroid and goitrogenic effect. The purpose of this study was to evaluate whether high doses of green and black tea have a harmful effect on thyroid physiology. Un-fractionated green and black tea extracts were administered orally to male rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%. The results showed that green tea extract at 2.5 g% and 5.0 g% doses and black tea extract only at 5.0 g% dose have the potential to alter the thyroid gland physiology and architecture, that is, enlargement of thyroid gland as well as hypertrophy and/or hyperplasia of the thyroid follicles and inhibition of the activity of thyroid peroxidase and 5(')-deiodinase I with elevated thyroidal Na+, K+-ATPase activity along with significant decrease in serum T3 and T4, and a parallel increase in serum thyroid stimulating hormone (TSH). This study concludes that goitrogenic/antithyroidal potential of un-fractionated green tea extract is much more than black tea extract because of the differences in catechin contents in the tea extracts.

Goitrogenic/antithyroidal potential of green tea extract in relation to catechin in rats

Catechins are flavonoids found in abundance in green tea, have elicited high interest due to their beneficial effects on health. Though flavonoids have been reported to have an antithyroid effect and also to be goitrogenic there have been no reports about the effect of green tea on rat thyroid. The present study was designed to examine whether high doses of green tea has any harmful effect on thyroid physiology. For this purpose green tea extract was administered orally to male albino rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%, respectively. Similarly, pure catechin was administered at doses of 25, 50 and 100mg/kg body weight which is equivalent to above doses of green tea extract. Lower body weight gain associated with marked hypertrophy and/or hyperplasia of the follicles was noted in the high dose of green tea and catechin treated groups. Decreased activity of thyroid peroxidase and 5'-deiodinase I and substantially elevated thyroidal Na,K+ATPase activity have been observed. Moreover, serum T3 and T4 levels were found to reduce followed by significant elevation of serum TSH. Taken together, these results suggest that catechin present in green tea extract might behave as antithyroid agent and possibly the consumption of green tea at high dose could alter thyroid function adversely.

Antioxidant enzyme activity and lipid peroxidation in the blood of rats co-treated with vanadium (V(+5)) and chromium (Cr (+3))

Selected biochemical parameters were studied in the blood of outbred, male Wistar rats which daily received to drink deionized water (Group I, control) or solutions of: sodium metavanadate (SMV; 0.100 mg V/mL)-Group II; chromium chloride (CC; 0.004 mg Cr/mL)-Group III; and SMV-CC (0.100 mg V and 0.004 mg Cr/mL)-Group IV for a 12-week period. The diet and fluid intake, body weight gain, and food efficiency ratio (FER) diminished significantly in the rats of Groups II and IV, compared with Groups I and III. The plasma total antioxidant status (TAS) as well as the MDA and the L: -ascorbic acid level in the erythrocytes (RBCs) remained unchanged in all the groups, whereas the plasma L: -ascorbic acid concentration decreased markedly in Group II, compared with Group III. The activities of Cu,Zn-superoxide dismutase (Cu,Zn-SOD), catalase (CAT), cellular glutathione peroxidase (cGSH-Px), and glutathione reductase (GR) in RBCs remained unaltered in all the treated rats. However, the activity of glutathione S-transferase (GST) and the content of reduced glutathione (GSH) in RBCs decreased and increased, respectively, in Groups II, III, and IV, compared with Group I. A vanadium-chromium interaction which affected the GST activity was also found. To summarize, SMV and CC administered separately or in combination in drinking water for 12 weeks did not alter either lipid peroxidation (LPO) or the activities of Cu,Zn-SOD, CAT, cGSH-Px, and GR, which allows a conclusion that both metals in the doses ingested did not reveal their pro-oxidant potential on RBCs.

Amelioration of vanadium-induced testicular toxicity and adrenocortical hyperactivity by vitamin E acetate in rats

Vanadium toxicity is a challenging problem to the health professionals and a cutting-edge medical problem. Vanadium has been recognized as industrial hazards that adversely affect human and animal reproductive health. Since testicular function is exquisitely susceptible to reactive-oxygen species, the present study elucidates the possible involvement of oxidative stress in vanadium-induced testicular toxicity and the prophylactic effects of vitamin E acetate against such adverse effects of vanadium. The study also characterizes the effects of vanadium on rat adrenal steroidogenesis and determines the underlying mechanisms of testicular and adrenal interactions in response to vanadium exposure. Significantly reduced sperm count associated with decreased serum testosterone and gonadotropins level in the vanadium-injected group of rats compared to control substantially proves the ongoing damaging effects of vanadium-induced ROS on developing germ cells. This is in turn reflected in the appreciable increase in testicular lipid peroxidation level and decline in the activities of steroidogenic and antioxidant enzymes. However, oral administration of vitamin E acetate could protect testes from the toxic effects of vanadium. Vanadium also results in adrenocortical hyperactivity, as evidenced by the elevated secretion of glucocorticoids, adrenal gland hypertrophy and increased activity of adrenal Delta(5)3beta-HSD. However, reversibility of these alterations in adrenocortical activities was vividly reflected after vitamin E acetate supplementation. All these studies reveal that oxidative stress is the major mechanism of health deterioration and that vanadium can act as a stressor metal causing chronic stress effects through excitation of hypothalamo-pituitary-adrenal axis. However antioxidant support by vitamin E acetate may provide significant protection.