Potential role of vitamins in chromium induced spermatogenesis in Swiss mice

Cr (VI)-induced ribosomal DNA copy number variation is associated with semen quality impairment: Evidence from human to animal study

OBJECTIVES

This study aimed to analyze the possible role of rDNA copy number variation in the association between hexavalent chromium [Cr (VI)] exposure and semen quality in semen donors and further confirm this association in mice.

METHODS

In this cross-sectional study, whole blood and semen samples were collected from 155 semen donors in the Zhejiang Human Sperm Bank from January 1st to April 31st, 2021. Adult C57BL/6 J male mice were treated with different doses of Cr (VI) (0, 10, or 15 mg/kg b.w./day). Semen quality, including semen volume, total spermatozoa count, sperm concentration, progressive motility, and total motility, were analyzed according to the WHO laboratory manual. Cr concentration was detected using inductively coupled plasma mass spectrometry. The rDNA copy number was measured using qPCR.

RESULTS

In semen donors, whole blood Cr concentration was negatively associated with semen concentration and total sperm counts. Semen 5 S and 45 S rDNA copy numbers were negatively associated with whole blood Cr concentration and whole blood 5.8 S rDNA copy number was negatively associated with semen Cr concentration. In mice, Cr (VI) damaged testicular tissue, decreased semen quality, and caused rDNA copy number variation. Semen quality was related to the rDNA copy number in whole blood, testicular tissue, and semen samples in mice.

CONCLUSION

Cr (VI) was associated with decreased semen quality in semen donors and mice. Our findings suggest an in-depth analysis of the role of the rDNA copy number variation in the Cr (VI)-induced impairment of semen quality.

Effects of Aronia melanocarpa and Hypericum perforatum aqueous extracts on hexavalent chromium induced toxicity in rat's thyrocytes

BACKGROUND

Hexavalent chromium known as oxidizing agent is able to form reactive oxygen species. Aronia melanocarpa and Hypericum perforatum are two plants known for their antioxidant effects. Our study aimed to establish if CrVI induces apoptosis and structural changes in thyrocytes and if its effect can be counteracted by the administration of both extracts.

MATERIALS AND METHODS

Wistar rats divided in five groups: C - distilled water (DW), Cr - 75 mg/L CrVI in DW for 3 months, Cr 2 - 75 mg/L CrVI in DW for 3 months followed by 1 month DW, CrA - 3 months 75 mg/L CrVI in DW and 1 month Aronia 2.5% extract, CrH - 3 months 75 mg/L CrVI in DW and 1 month Hypericum 2.5% extract. Histological assessment and qRT-PCR for evaluation of BAX and Bcl2 protein levels performed on thyroid samples.

RESULTS

The Cr and Cr2 groups were those with altered cytoarchitecture: increase in the diameter of many thyroid follicles, a decrease in their number, a decrease in the height of the follicular cells. The histological examination of the CrH group revealed almost recovery of structural architecture. The BAX gene levels were higher in the Cr and Cr2 groups indicating the apoptotic activity of chromium. In extract receiving groups the BAX gene expressions were significantly lower, but the lowest level presented the CrH group. Bcl2 gene expression levels indicate antiapoptotic activity being elevated in the Cr group, followed by CrA, Cr2, and CrH groups. The BAX/Bcl2 ratio which significantly increased in the case of the Cr and Cr2 group compared to the groups that were administered the two plant extracts.

CONCLUSION

The results obtained in this study confirm that CrVI has toxic effects on thyroid endocrine cells and H. perforatum has stronger antioxidant properties against the action of hexavalent chromium in thyrocytes than A. melanocarpa.

Toxic and carcinogenic effects of hexavalent chromium in mammalian cells in vivo and in vitro: a recent update

Chromium VI (Cr (VI)) can cross cell membranes readily and causes the formation of Cr-DNA adducts, genomic damages, elevation of reactive oxygen species (ROS) and alteration of survival signaling pathways, as evidenced by the modulation in p53 signaling pathway. Mammals, including humans are exposed to Cr, including Cr (VI), frequently through inhalation, drinking water, and food. Several studies demonstrated that Cr (VI) induces cellular death through apoptosis and autophagy, genotoxicity, functional alteration of mitochondria, endocrine and reproductive impairments. In the present review, studies on deleterious effects of Cr (VI) exposure to mammalian cells (in vivo and in vitro) have been documented. Special attention is paid to the underlying molecular mechanism of Cr (VI) toxicity.

The effects of natural active substances in food on the toxicity of patulin

Patulin (PAT) is a mycotoxin, a secondary metabolite mainly produced by fungi of the genera Aspergillus, Byssochlamys, and Penicillium. Many studies have looked into the potential impacts of this mycotoxin due to its high risk. Researchers are currently doing a more in-depth investigation of and employing physical, chemical, and biological ways to remove PAT. However, existing technology cannot completely remove it, and the residual PAT will continue to pose a threat to human health. As a result, substances capable of reducing PAT toxicity need be discovered. According to previous studies, natural components in food could reduce the toxicity of PAT. This article will review the different types of active compounds and discus the detoxification processes, as well as give recommendations for decreasing the toxicity of PAT and future research directions.

Impact of Environmental and Lifestyle Use of Chromium on Male Fertility: Focus on Antioxidant Activity and Oxidative Stress

Male reproductive tissues are strongly susceptible to several environmental and lifestyle stressors. In general, male reproductive health is highly sensitive to oxidative stress, which results in reversible and/or irreversible changes in testosterone-producing cells, spermatogenesis, and sperm quality. Chromium compounds are widely used in the +3 and +6 valence states, as food supplements, and in the industrial field, respectively. Chromium (III) compounds, i.e., Cr(III)-tris-picolinate, [Cr(pic)₃], known as chromium picolinate, are used as nutritional supplements for the control of diabetes, body weight, and muscular growth. However, previous studies showed that animal models exposed to chromium picolinate experienced degenerative changes in spermatogenesis. Contradictory results are documented in the literature and deserve discussion. Furthermore, the long-term effects of chromium picolinate on the antioxidant system of treated subjects have not been properly studied. Comprehensive studies on the role of this compound will help to establish the safe and useful use of chromium supplementation. On the other hand, chromium (VI) compounds are widely used in several industries, despite being well-known environmental pollutants (i.e., welding fumes). Chromium (VI) is known for its deleterious effects on male reproductive health as toxic, carcinogenic, and mutagenic. Previous studies have demonstrated severe lesions to mouse spermatogenesis after exposure to chromium (VI). However, workers worldwide are still exposed to hexavalent chromium, particularly in electronics and military industries. Data from the literature pinpoints mechanisms of oxidative stress induced by chromium compounds in somatic and germ cells that lead to apoptosis, thus underlining the impairment of fertility potential. In this review, we analyze the benefits and risks of chromium compounds on male fertility, as well as the mechanisms underlying (in)fertility outcomes. Although supplements with antioxidant properties may maximize male fertility, adverse effects need to be investigated and discussed.

Pathogenic Mechanisms and Therapeutic Implication in Nickel-Induced Cell Damage

Background:

Nickel (Ni) is mostly applied in a number of industrial areas such as printing inks, welding, alloys, electronics and electrical professions. Occupational or environmental exposure to nickel may lead to cancer, allergy reaction, nephrotoxicity, hepatotoxicity, neurotoxicity, as well as cell damage, apoptosis and oxidative stress.

Methods:

In here, we focused on published studies about cell death, carcinogenicity, allergy reactions and neurotoxicity, and promising agents for the prevention and treatment of the toxicity by Ni.

Results:

Our review showed that in the last few years, more researches have focused on reactive oxygen species formation, oxidative stress, DNA damages, apoptosis, interaction with involving receptors in allergy and mitochondrial damages in neuron induced by Ni.

Conclusion:

The collected data in this paper provide useful information about the main toxicities induced by Ni, also, their fundamental mechanisms, and how to discover new ameliorative agents for prevention and treatment by reviewing agents with protective and therapeutic consequences on Ni induced toxicity.

Correlation between urinary chromium level and semen quality in men attending an andrology laboratory

Chromium is an essential element that is required for the normal physiology but can be toxic to humans above a certain level. In spite of growing interest in research on chromium exposure to human health consensus about its effect on human, semen quality has not been achieved. The aim of the present study is to evaluate the impact of chromium exposure on semen parameters. A total of 760 males attending andrology laboratory of Tongji Hospital, Wuhan, for routine semen analysis were enrolled and requested to provide semen and urine samples. The urine level of chromium was evaluated using inductively coupled plasma mass spectrometry (ICP-MS), and computer-assisted semen analysis (CASA) was applied to examine semen parameters. Associations between semen parameters and urinary chromium were analyzed by means of multivariate linear regression analysis. Multivariate analysis showed a negative association between the urinary concentrations of chromium and progressive motility (β = - 0.014, p = 0.040) and total motility (β = - 1.077, p = 0.048), while other semen parameters did not show any statistically significant changes. Urinary chromium could influence semen quality parameters and impair male fecundity.

Carcinogenicity of chromium and chemoprevention: a brief update

Chromium has two main valence states: hexavalent chromium (Cr[VI]) and trivalent chromium (Cr[III]). Cr(VI), a well-established human carcinogen, can enter cells by way of a sulfate/phosphate anion-transport system, and then be reduced to lower-valence intermediates consisting of pentavalent chromium (Cr[V]), tetravalent chromium (Cr[IV]) or Cr(III) via cellular reductants. These intermediates may directly or indirectly result in DNA damage or DNA–protein cross-links. Although Cr(III) complexes cannot pass easily through cell membranes, they have the ability to accumulate around cells to induce cell-surface morphological alteration and result in cell-membrane lipid injuries via disruption of cellular functions and integrity, and finally to cause DNA damage. In recent years, more research, including in vitro, in vivo, and epidemiological studies, has been conducted to evaluate the genotoxicity/carcinogenicity induced by Cr(VI) and/or Cr(III) compounds. At the same time, various therapeutic agents, especially antioxidants, have been explored through in vitro and in vivo studies for preventing chromium-induced genotoxicity/carcinogenesis. This review aims to provide a brief update on the carcinogenicity of Cr(VI) and Cr(III) and chemoprevention with different antioxidants.

Mechanisms of chromium hexavalent-induced apoptosis in rat testes

Hexavalent chromium (CrVI)-containing compounds, present in industrial settings and in the environment, are known as carcinogens and mutagens. The present study is designed to test the hypothesis that oxidative stress mediates CrVI-induced apoptosis in testis. Male Wistar rats received an intraperitoneal injection of potassium dichromate at doses of 1 and 2 mg kg^-1. Superoxide anion production was assessed by the determination of the reduction of cytochrome c and iodonitrotetrazolium, lipid peroxidation (LPO), metallothioneins (MTs), and catalase (CAT) activity. Apoptosis was evaluated by DNA fragmentation detected by agarose gel electrophoresis. Germinal cells apoptosis was detected by toluidine blue staining. The expression of Bax and Bcl-2 proteins (Pts) was also investigated. After 15 days of treatment, an increase of LPO and MT levels occurred, while CAT activity was decreased. Testicular tissues of treated rats showed pronounced degradation of the DNA into oligonucleotides as seen in the typical electrophoretic DNA ladder pattern. Intense apoptosis was observed in germinal cells of Cr-exposed rats. Bax Pt expression was induced in spermatogonia and spermatocytes cells of CrVI-treated rats. In contrast, Bcl-2 Pt was occasionally observed in germ cells of CrVI-exposed rats. These results clearly suggest that CrVI subacute treatment causes oxidative stress in rat testis leading to apoptosis.

Hexavalent chromium affects sperm motility by influencing protein tyrosine phosphorylation in the midpiece of boar spermatozoa

Hexavalent chromium reportedly induces reproductive toxicity and further inhibits male fertility in mammals. In this study, we investigated the molecular mechanism by which hexavalent chromium affects motility signaling in boar spermatozoa in vitro. The results indicated that Cr(VI) decreased sperm motility, protein phosphorylation, mitochondrial membrane potential (ΔΨm) and metabolic enzyme activity starting at 4μmol/mL following incubation for 1.5h. Notably, all parameters were potently inhibited by 10μmol/mL Cr, while supplementation with the dibutyryl-cAMP (dbcAMP) and the 3-isobutyl-1-methylxanthine (IBMX) prevented the inhibition of protein phosphorylation. Interestingly, high concentrations of Cr (>10μmol/mL) increased the tyrosine phosphorylation of some high-molecular-weight proteins in the principle piece but decreased that in the middle piece associated with an extreme reduction of sperm motility. These results suggest that chromium affects boar sperm motility by impairing tyrosine phosphorylation in the midpiece of sperm by blocking the cAMP/PKA pathway in boar sperm in vitro.

Effect of hexavalent chromium-treated sperm on in vitro fertilization and embryo development

Hexavalent chromium (Cr(VI)) is an environmental contaminant that is associated with reproductive abnormalities in both humans and animals. In the present study, we evaluated the cytotoxic effect of Cr(VI) on sperm function and subsequent embryo development after in vitro fertilization (IVF). Sperm obtained from BDF1 male mice were treated with potassium dichromate (0, 3.125, 6.25, 12.5, 25, or 50 μM) for 3 h. Cr(VI) significantly decreased sperm viability and acrosome reaction with increasing dose. These Cr(VI)-treated sperms were further used for IVF of oocytes obtained from BDF1 female mice. Results showed that Cr(VI)-treated sperm caused a significant reduction in IVF success, higher developmental arrest at the two-cell stage of embryos, and delayed blastocyst formation with increasing dose. In particular, most blastocysts from the Cr(VI)-treated sperm resulted in hatching failure as well as decreased inner cell mass and trophectoderm (TE). Furthermore, blastocysts obtained from Cr(VI)-treated sperm showed lower expression of not only TE-associated genes (eomes, cdx2, and krt8) but also pluripotent marker genes (sox2, pou5f1, and klf4) that are responsible for further embryo development of blastocyst embryos. The results of our current study showed that Cr(VI)-treated sperm had negative effects on oocyte fertilization and subsequent embryo development.

Reproductive toxicity in adult male rats following intra-articular injection of cobalt-chromium nanoparticles

BACKGROUND

Recent studies have reported that metallic nanoparticles and ions from cobalt-chromium (CoCr) alloy prostheses had potential adverse effects. However, the biological effects of CoCr nanoparticles on male reproductive function remain unclear. The objective of this study is to investigate the reproductive toxicity in adult male rats following intra-articular injection of cobalt-chromium nanoparticles.

METHODS

CoCr nanoparticles were generated by a spark discharge method. Adult male rats received intra-articular injections of CoCr nanoparticles once a week at a low (20 μg/kg b.w.), medium (100 μg/kg b.w.) or high dose (500 μg/kg b.w.) for 10 consecutive weeks. The control group received intra-articular injections of physiological saline. After the final injection, all rats were held for a 7-day post-exposure period. The effects on male reproductive function were observed, including the coefficient of testicular to body weight, the epididymal sperm parameters, the concentration of metal ions in serum and testis, the activity of antioxidase and the content of lipid peroxide in the testis, and histopathological examination.

RESULTS

Compared with the control group, intra-articular injection of high dose CoCr nanoparticles could significantly reduce epididymal sperm motility, viability and concentration, increase abnormal sperm rate and levels of Co and Cr ions in serum and in the testis, and induce testicular damage and pathological changes via oxidative stress.

CONCLUSIONS

Intra-articular injection of high dose CoCr nanoparticles from MOM articulation may have potential reproductive toxicity in adult male rats.

Antioxidative and antigenotoxic effect of vitamin E against patulin cytotoxicity and genotoxicity in HepG2 cells

Patulin (PAT) is a mycotoxin produced in fruits, mainly in apples, by certain species of Penicillium, Aspergillus, and Byssochlamys. It has been shown that PAT is cytotoxic, genotoxic, and mutagenic in different cell types. Several studies incriminate the oxidative stress as a mechanism of PAT-mediated toxicity. In this context, our aim was to investigate the protective role of Vitamin E (Vit E), an antioxidant agent, against PAT induced cytotoxicity and genotoxicity in cultured HepG2 cells. The obtained results showed that addition of Vit E in cells treated with PAT significantly reduce cell mortality induced by this toxin. In the same conditions, Vit E decreased the intracellular level of ROS, reduced PAT induced p53 expression, and reversed PAT induced DNA damage. In addition, Vit E prevented significantly the percentage of chromosome aberrations induced by PAT in HepG2 cells in a concentration dependant manner. These results suggest that Vit E, an exogenous antioxidant agent, plays an important role in defense against PAT-induced cytotoxicity and genotoxicity, which confirms the involvement of oxidative stress in the induction of DNA damage by PAT in HepG2 cells.

The effect of enrofloxacin on sperm quality in male mice

Current study was designed to evaluate toxic effects of enrofloxacin on male mice reproductive system. In the treatment group enrofloxacin was administered subcutaneously to male mice at a fixed dose of 150 mg/kg once daily for 15 days, whereas saline solution was given in the same regimen in the control group for the same period. Mice were sacrificed on day 15 and analyzed for sperm quality. In addition to routine examination of sperm material, spermatogenetic activity and organization of each animal were graded according to Johnsen's scoring to assess the spermatogenesis relying on seminiferous tubule cross-section scores. A significant decrease in both epididymal sperm count and sperm motility besides abnormal spermatozoa rate were observed in enrofloxacin group compared to controls (P < 0.01, for all). Johnsen's score in control mice were better than those in treatment group (P < 0.01). These results suggested that a fixed 150 mg/kg dose of enrofloxacin would lead disruption of spermatogenesis in the testes causing deterioration of motility and content of sperms as well as morphological abnormalities.

Effect of curcumin on chromium-induced oxidative damage in male reproductive system

Hexavalent chromium, an environmental contaminant, undergoes redox cycling with generation of free radicals inside the biological system. Curcumin, the yellow bioactive component of turmeric has established its antioxidant activities. The present study evaluates possible ameliorating effects of curcumin on potassium dichromate (K(2)Cr(2)O(7)) (hexavalent chromium) induced reproductive toxicity in adult male Sprague-Dawley rats. Three experimental groups, each consisting of eight rats, were treated with 0.4mg K(2)Cr(2)O(7)/kg bw/day, 0.4mg K(2)Cr(2)O(7)/kg bw/day+20mg curcumin/kg bw on every alternate day and 20mg curcumin/kg bw on every alternate day, respectively, for 26 days. Altered testicular histology, reduced sperm count, low testosterone level, decreased accessory sex organs weight, enhanced lipid peroxidation along with reduced SOD and catalase activities were observed following K(2)Cr(2)O(7) exposure while curcumin supplementation along with K(2)Cr(2)O(7) exposure had shown to prevent the altered parameters. The results thus suggest that curcumin may have a protective role against chromium(VI) induced oxidative damage in male reproductive system.

Protective effects of vitamin E on ethane dimethane sulfonate-induced testicular toxicity in rats

AIM

To evaluate the protective/ameliorative effects of vitamin E (vit E) on ethane dimethane sulfonate (EDS)-induced testicular toxicity in rats.

METHODS

The rats were assigned to eight groups, seven rats in each, and were injected intraperitoneally with vehicle, a single dose of ethane dimethane sulfonate (EDS) (75 mg/kg bodyweight), vit E (100 mg/kg bodyweight) or EDS + vit E for 3? days. Thereafter, the rats were weighed, anaesthetized with ether and killed by cervical dislocation. The left testis weights were recorded and the relative testis weights were calculated. The left testes were processed for routine paraffin embedding. Three right testes from each group were taken randomly and then processed for routine electron microscopy. Tissue sections were examined using light and electron microscopy, and were scored for histopathological changes.

RESULTS

Vit E coadministration did not prevent the bodyweight loss on days 3 and 7. However, vit E administration prevented the EDS-induced testicular-weight loss in rats that received vit E for 3 days but not 7 days. The relative testis weight was higher on day 3 (instead of on day 7) than other groups. Nevertheless, the testis histology was not markedly protected by vit E in the EDS-treated rats. Detailed microscopic assessment showed few Leydig cells and abundant fibroblast-like cells indicating only some protection.

CONCLUSION

Vit E cotreatment showed partial protective effects on the testicular weight and testicular histology in rats that received EDS.

Testicular dysfunction and antioxidative defense system of Swiss mice after chromic acid exposure

Chromic acid (CrO(3)), a hexavalent compound of chromium (Cr) that is widely used in different industries, has been associated with reproductive abnormalities in male Swiss mice. The mechanism of male reproductive toxicity is not clear. Metal-induced reactive oxygen species (ROS) may impair spermatogenesis or alter sperm morphology. Therefore, in the present study we investigated the induction of oxidative stress in the testes of mice over time (5th-8th weeks) after a single intraperitoneal dose (1mg/kg body weight) of CrO(3). Exposed animals showed significantly decreased sperm counts and markedly increased rates of sperm abnormality. Oxidative stress was measured in terms of malondialdehyde content, the activities of superoxide dismutase, peroxidase, and catalase, and non-enzymatic antioxidants such as ascorbic acid. The significant changes in exposed groups relative to controls suggest that CrO(3) exposure suppressed antioxidant enzymes and ascorbic acid with a concomitant increase in the level of lipid peroxidation and H(2)O(2) to adversely affect testicular function.

Effects of diazinon on pseudocholinesterase activity and haematological indices in rats: The protective role of Vitamin E

Diazinon (DZN) is an organophosphate insecticide has been used in agriculture and domestic for several years. Vitamin E (200mg/kg, twice a week), diazinon (10mg/kg, per day) and Vitamin E (200mg/kg, twice a week)+diazinon (10mg/kg, per day) combination were given to rats orally via gavage for 7 weeks. Pseudocholinesterase in serum and haematological indices were investigated at the end of the 1st, 4th and 7th weeks comparatively with control group. At the end of 1st, 4th and 7th weeks, statistically significant decrease of pseudocholinesterase activity in serum were detected when diazinon- and Vitamin E+diazinon-treated groups compared to control group. When diazinon- and Vitamin E+diazinon-treated groups were compared to each other there were no significant changes. When diazinon-treated group was compared to control group, body weight decreased significantly at the end of the 4th and 7th weeks. It was observed that at the end of 1st, 4th and 7th weeks, there was a statistically significance in haematological indices except mean corpuscular hemoglobin (MCH) when diazinon-treated group was compared to control group. At the end of 1st week increase of thrombocyte, at the end of the 4th week increase of hemoglobin and thrombocyte and at the end of the 7th week increase of red blood cell (RBC), hemoglobin, hematocrit, mean corpuscular hemoglobin concentration (MCHC) and thrombocyte were observed statistically significant when Vitamin E+diazinon treated group was compared with diazinon treated group. According to the present study, we conclude that Vitamin E reduces diazinon toxicity, but it does not protect completely.

Ameliorating effect of folic acid on chromium(VI)-induced changes in reproductive performance and seminal plasma biochemistry in male rabbits

Chromium hexavalent (Cr(VI)) is a biologically active oxidized state of chromium. It is involved in the redox cycle, with the production of reactive oxygen species. Free radical scavenging properties and possible antioxidant activity of folic acid (FA) have been reported; therefore, the present study examined possible protective effects of FA on the reproductive toxicity of potassium dichromate (K2Cr2O7) in male New Zealand white rabbits. We monitored reproductive performance, lipid peroxidation, enzyme activities and biochemical parameters in seminal plasma. Six rabbits per treatment group (and a control group) were exposed: 8.3 microg/kg FA; 5 mg/kg potassium dichromate (contains 3.6 mg chromium(VI)) and 5 mg/kg potassium dichromate+8.3 microg/kg FA. Results showed that semen quality deteriorated following potassium dichromate exposure. Testosterone levels, body weight (BW), relative weights of testes (RTW) and epididymis (REW) all decreased. Levels of thiobarbituric acid-reactive substances increased, whereas the activities of glutathione S-transferase, transaminases and phosphatases decreased in the seminal plasma. FA alone significantly increased BW, RTW, REW, semen characteristics and seminal plasma enzymes, and decreased the levels of free radicals. Furthermore, FA can be effective in the protection of chromium-induced reproductive toxicity.