Chronic effects of low lead levels on sperm quality, gonadotropins and testosterone in albino rats

Evaluation of the camel milk amelioration, the oxidative stress, fertility and mutagenicity of male albino rats exposed to lead acetate, fipronil, and their mixture

Lead is considered a common old chronic toxicant around the world due to expanded environmental pollution, it is likely an inevitable contaminant in food, dairy products, air etc. Also, fipronil is a wide-ranging effective N-phenyl pyrazole insecticide which used commonly in agriculture and public health insect control, but until now no adequate data are available on the oxidative stress, cytotoxicity, and mutagenic influence of fipronil and lead or their mixture subchronic exposure. Both xenobiotics (lead and fipronil) exert a harmful impact on reproduction, prompting the exploration of various foods for functional protection. The present study investigated the effects of camel milk treatments on reproductive problems caused by lead acetate with or without mixing with fipronil in male albino rats. Liver oxidative stress, testicular relative weight, sperm analysis, investigation of chromosomal aberration, and histopathological examination of testis were performed. The results showed that the oxidative stress was elevated in rats treated with fipronil, lead acetate, and their mixture, which were reduced through camel milk treatments. Sperm counts were decreased significantly in lead and/or fipronil exposure but significantly elevated with camel milk intoxicated treated. Sperm morphological abnormalities and chromosomal aberrations in intoxicated groups were reduced significantly in camel milk-treated animals relative to untreated intoxicated groups. Testicular histopathological results showed moderate common degeneration of seminiferous tubules in lead and/or fipronil-intoxicated rats which were ameliorated by camel milk treatments. Generally, it can be concluded that lead and fipronil together in a mixture resulted in or induced severe reproductive problems and oxidative stress over lead or fipronil alone. Camel milk treatment significantly decreased the harmful oxidative stress in reproductive as well as the mutagenicity disorder associated with lead and fipronil exposure in male albino rats.

Serum and Seminal Plasma Levels of Lead and Arsenic in Cigarette Smokers and Their Relation to the Semen Parameters

Male infertility along with altered semen parameters have been related to smoking. Smoking-related elevations in serum and seminal lead (Pb) and arsenic (As) may play a role in mediating the toxic effects of smoking on seminogram. This research aims to determine whether smoking has any significant impact on Pb and As levels in the seminal plasma and serum, as well as on the various semen parameters, when compared to nonsmokers. In total, 80 adult males were included: 60 smokers and 20 age-matched nonsmokers. Based on the number of cigarettes smoked/day (CPD), the smokers were categorized into mild (1-10), moderate (11-20), and severe (> 20). The analysis of semen was conducted in accordance with the 2010 WHO laboratory manual. Using an atomic absorption spectrophotometer, Pb and As concentrations in the serum and seminal plasma of all groups were determined. Compared to nonsmokers, smokers had a significantly reduced sperm count, motility, and viability, as well as a larger percentage of aberrant forms (P = 0.001, 0.025, 0.034, 0.002 respectively). Smokers had higher Pb concentrations in their serum and seminal fluid than nonsmokers (P = 0.002, 0.001 respectively). Seminal Pb had a significant negative correlation with sperm count (P = 0.004, r = -0.320). Serum Pb levels were found to positively correlate with seminal Pb levels (P 0.001, r = 0.648), and cigarette smokers had substantially greater seminal As levels than nonsmokers (P = 0.024). Sperm viability was strongly inversely related to seminal As (P = 0.042, r = -0.264). Seminal As levels and aberrant sperm shapes were found to be significantly correlated (P = 0.001, r = 0.414). In smokers, a significant positive relationship between seminal As and seminal Pb was observed. Therefore, semen parameters could be adversely affected by smoking through high levels of Pb and As (P = 0.012, r = 0.298).

The influence of lead exposure on male semen parameters: a systematic review and meta-analysis

Lead (Pb) is a metal with a widespread diffusion in the environment. Pb tends to accumulate in the human body and, as a consequence, semen alterations can be present in exposed workers or general population. The aim of the present study is to evaluate the effect on semen parameters among healthy men exposed to environmental or occupational Pb. A systematic literature search was performed on November 12^th, 2022, through MEDLINE via PubMed, Scopus, and Embase. Observational studies comparing semen parameters in men exposed to Pb and those not exposed were included. Sperm parameters were pooled using the Cochran-Mantel-Haenszel Method with a random effect model. The weighted mean difference (WMD) was used as a summary measure. Statistical significance was set at p-value <0.05 Ten papers were included. Pb exposure was associated with a significant reduction in semen volume (WMD -0.76ml.95% CI -1.47, -0.05, p=0.04), sperm concentration (WMD -0.63 ×10⁶/ml 95% CI -1.15, -0.12, p=0.02), total sperm count (WMD -1.94 ×10⁶ 95% CI -3. 77, -0.11, p=0.04), sperm vitality (WMD -2.18% 95% CI -3.92, -0.45, p=0.01), and total sperm motility (WMD -1.31% 95% CI -2.33, -0.30, p=0.01). No difference was found in sperm normal morphology, progressive motility, and seminal viscosity. This review demonstrated the negative effect of Pb exposure on most of semen parameters. Given the diffuse exposure to this metal of the general population, public health concerns should be considered and exposed workers should be assessed to evaluate their semen. DATA AVAILABILITY STATEMENT: Data will be provided by the corresponding author upon a reasonable request.

Wild Garlic Allium triquetrum L. Alleviates Lead Acetate-Induced Testicular Injuries in Rats

The current study investigates the potential alleviating activity of bulbs (B) and leaves (L) of Allium triquetrum aqueous extract (ATE) on repro-toxicity induced by lead acetate (Pb) in male Wistar rats administrated orally for 3 consecutive weeks. Eighteen groups of rats were divided into the control, Pb (500 mg/kg body weight/day), positive controls of B and L (2 g, 3 g, 4 g, 6 g/kg body weight/day), in addition to four mixtures of each of Pb-B (Pb-B1, Pb-B2, Pb-B3, Pb-B4) and Pb-L (Pb-L1, Pb-L2, Pb-L3, Pb-L4). The two extracts were subjected to phytochemical screening and HPLC analysis. Sperm characteristics were evaluated by CASA system, as well as the serum testosterone, testicular and epididymal levels of glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA). The phytochemical screening proved that bulbs' and leaves' extracts were rich in various compounds and the HPLC showed that leaves contain more tannins. Results revealed a significant decrease in the testicular and in the epididymal weights, sperm concentration, motility, testosterone, velocity, vitality, round cells, GSH, and GPx levels in the Pb-intoxicated rats compared to the control, with the exception of MDA concentration that was significantly increased. However, the co-administration of garlic extracts (Pb-B and Pb-L) exhibited a significant increase in all mentioned markers, except for the MDA level which was reduced. Likewise, Pb caused histological injuries in the testicular seminiferous of rats, while the co-administration of wild garlic has reduced such effect, especially in the higher doses. Both extracts of Pb-B and Pb-L have attenuated Pb toxicity in a dose-dependent manner. In conclusion, aqueous extracts of A. triquetrum have the potential to reduce Pb testicular injuries by boosting sperm characteristics and ameliorating oxidative stress markers.

Chlorella vulgaris or Spirulina platensis mitigate lead acetate-induced testicular oxidative stress and apoptosis with regard to androgen receptor expression in rats

The current research was constructed to throw the light on the protective possibility of Chlorella vulgaris (C. vulgaris) and Spirulina platensis (S. platensis) against lead acetate-promoted testicular dysfunction in male rats. Forty rats were classified into four groups: (i) control, (ii) rats received lead acetate (30 mg/kg bw), (iii) rats concomitantly received lead acetate and C. vulgaris (300 mg/kg bw), (vi) rats were simultaneously treated with lead acetate and S. platensis (300 mg/kg bw) via oral gavage for 8 weeks. Lead acetate promoted testicular injury as expressed with fall in reproductive organ weights and gonadosomatic index (GSI). Lead acetate disrupted spermatogenesis as indicated by sperm cell count reduction and increased sperm malformation percentage. Lead acetate-deteriorated steroidogenesis is evoked by minimized serum testosterone along with maximized follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels. Testicular oxidative, inflammatory, and apoptotic cascades are revealed by elevated acid phosphatase (ACP) and sorbitol dehydrogenase (SDH) serum leakage, declined testicular total antioxidative capacity (TAC) with elevated total oxidative capacity (TOC), tumor necrosis factor alpha (TNF-α), caspase-3 levels, lessened androgen receptor (AR) expression, and histopathological lesions against control. Our research highlights that C. vulgaris or S. platensis therapy can modulate lead acetate-promoted testicular dysfunction via their antioxidant activity as expressed by elevated TAC and reduced TOC, immunomodulatory effect as indicated by lessened TNF-α level, and anti-apoptotic potential that was revealed by minimized caspase-3 levels. As well as restoration of testicular histoarchitecture, androgen receptor, steroidogenesis, and spermatogenesis were detected with better impacts to S. platensis comparing with C. vulgaris. Therefore, further clinical trials are needed to test S. platensis and C. vulgaris as a promising candidate in treating male infertility.

Effects of heavy metals on reproduction owing to infertility

The reproductive performance of most of the species is adversely affected by hazardous heavy metals like lead, cadmium, mercury, arsenic, zinc, and copper. Heavy metals are liberated in the environment by natural sources like rock weathering, volcanic eruption, and other human activities like industrial discharge, mineral mining, automobile exhaust, and so forth. Heavy metals alter several reproductive functions in both males and females like a decrease in sperm count, motility, viability, spermatogenesis, hormonal imbalance, follicular atresia, and delay in oocyte maturation, and so forth, and thus, forms an important aspect of reproductive toxicology. The present review compiles toxicity aspects of various heavy metals and their efficacy and mechanism of action in mammals.

Ferulago angulata extract ameliorates epididymal sperm toxicity in mice induced by lead and diazinon

BACKGROUND

The potential toxicity that results from environmental xenobiotics is not completely known. Increasing levels of heavy metals and the use of organophosphate pesticides (OPs) and their co-existence in the environment could be associated with an increasing incidence of male reproductive system disorders in humans and animals. Ferulago angulata is a dietary source of phenolic compounds with reported health benefits.

OBJECTIVE

This study was conducted to investigate whether an extract of Ferulago angulata could protect adult male NMRI mice against reproductive toxicity induced by lead acetate (PbAc), diazinon (DZN), or PbAc + DZN.

MATERIALS AND METHODS

Adult male NMRI mice were exposed to either 0.5% PbAc in drinking water, DZN (3 mg/kg/day, intraperitoneal [i.p.] injection), or PbAc + DZN in the presence or absence of 400 mg/kg/day Ferulago angulata hydroalcoholic extract (FAE) that was administered via gavage for 6 weeks.

RESULTS

Chronic exposure to PbAc, DZN, and PbAc + DZN decreased sperm quality, sperm chromatin maturity and integrity, increased oxidative stress and lipid peroxidation, and could reduce male fertility indices. Co-administration of FAE could reduce these negative effects.

CONCLUSION

The Ferulago angulata extract should be considered as a useful natural extract for the treatment of male infertility, especially in males exposed to conditions which induce reproductive toxicity.

The Relationship between Exposure to Lead-Containing Welding Fumes and the Levels of Reproductive Hormones

Background

Inhalation of lead oxide fumes may cause lead poisoning. Lead has been proven to have harmful effects on different organs. This study aimed to investigate the relationship between the concentration of lead fumes and the levels of reproductive hormones among exposed welders.

Methods

A total number of 165 individuals of a construction industry of water pipelines, including 85 welders as the exposure group and 80 administrative staff as the non-exposure group were selected for study. The National Institute for Occupational Safety and Health (NIOSH) 7300 method was used for the purpose of sampling and analysis of lead fumes. Likewise, the NIOSH 8003 method was employed to determine the blood lead level. The level of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone were measured by Chemiluminescence immunoassay(CLIA) test. Data analyses were done by SPSS ver.21 using descriptive statistics, Student›s t-test and Spearman›s correlation test.

Results

The average concentration of lead fumes in the breathing zone and blood were 0.57 ± 0.12 mg/m³ and 460.28 ± 93.65 μg/L, correspondingly, which both were significantly higher than threshold limit values (TLV) and biological exposure index (BEI) recommended by American Conference of Governmental Industrial Hygienists (ACGIH)(P < 0.05). The mean levels of LH and FSH were higher in the exposed group than those in the control group (P < 0.05), however, the mean levels of testosterone were lower in the exposed group compared to non-exposed ones (P < 0.05). A strong correlation was found between the concentration of lead fumes and the blood lead levels (r = 0.82; P = 0.003). Blood lead levels were inversely related to the testosterone levels and directly related to LH (r = 0.72; P = 0.004) and FSH (r = 0.78; P = 0.001) levels.

Conclusions

Occupational exposure to metal fumes containing lead among welders may alter the level of sexual hormones and potentially harm the reproductive system.

Thymoquinone attenuates testicular and spermotoxicity following subchronic lead exposure in male rats: Possible mechanisms are involved

AIMS

The testis is one of the main target organs for lead (Pb) toxicity. The current study was investigated the mechanism (s) of the therapeutic potential of thymoquinone (TQ), the active principle of Nigella sativa seed, against testicular toxicity following subchronic Pb exposure in the light of cytopathic effects, apoptotic signaling pathways, oxidative stress, serum sex hormones levels and testicular aromatase gene expression.

MATERIALS AND METHODS

Thirty-two male albino rats were randomly allocated into control, PbAc (20 mg PbAc/kg bwt, orally), TQ (5 mg TQ/kg bwt dissolved in corn oil, orally), and PbAc + TQ groups for 56 successive days.

KEY FINDINGS

PbAc-treated rats showed significant decrease of testes and epididymes weights, sperm count, motility and viability, spermatogenesis score and serum FSH, LH, testosterone and estradiol levels, as well as a significant decreased testicular antioxidant molecules (Superoxide dismutase enzyme and reduced glutathione), and a significant elevation of sperm abnormalities, oxidative biomarkers (Malondialdehyde and Nitric oxide) compared to a control group. In addition, Pb induced significant downregulation of aromatase gene expression, activation of Bax and Caspase-3 apoptotic pathways. Moreover, Pb caused complete seminiferous tubules hyalinization (38%), germinal epithelium sloughing (15%) and hypocellularity (8%). However, administration of TQ with PbAc improved sperm quality, testicular histology and oxidative/antioxidative status, and serum levels of LH, testosterone and E2 with respect to PbAc group. Additionally, TQ with PbAc significantly lessen the staining intensity and the area of Bax and Caspase-3 immunoexpression.

SIGNIFICANCE

TQ might exert its acceptable therapeutic potential against Pb-induced testicular and spermotoxicity via anti-oxidative, endocrine and anti-apoptotic pathways.

Prophylactic effect of Nigella sativa against lead acetate induced changes in spermiogram, reproductive hormones and gonadal histology of rats

AIM

This study was designed to evaluate the prophylactic effect of Nigella sativa (NS) treatment on toxic effects induced by lead acetate (LA) on the reproductive hormones, spermiogram and gonadal histology of rats.

MATERIALS AND METHODS

A total of 20 Sprague-Dawley rats were divided into four groups of five rats each. Group 1 (negative control [NC]) was the NC and was given distilled water, Group 2 served as the positive control (PC) and was administered 10 mg/kg/day of LA per overall survival (OS), Group 3 (T1) was administered 200 mg/kg/daily of NS per OS for a month, and Group 4 (T2) was pretreated with 200 mg/kg/daily of NS per OS for 1 month, followed by 10 mg/kg/daily of LA alone per OS for another. The rats were euthanized at the end of the experimental period for collection of blood and the right caudal epididymis and testis. Serum was used for determination of reproductive hormones by using radioimmunoassay kits. The epididymal segment was cut and homogenized in phosphate-buffered saline, and the homogenate was used for determination of the spermiogram parameters such as sperm concentration, sperm viability, percentage of live sperm, motility and abnormality. Both the epididymis and testis were fixed in 10% buffered formalin for histological processing.

RESULTS

The sperm concentration, general, and individual motilities were higher (p<0.05) in the NC and T1 animals, while the T2 had intermediate and the PC had lower (p<0.05) values of each parameter. The percentage sperm viability was higher (p<0.05) in the T1 and lower (p<0.05) in the PC group. However, percentage abnormality was lower in T1, comparable in NC and T2, and higher (p<0.05) in PC. Spermatogenic cell population and epididymal sperm reserve (ESR) were optimal in control and pretreated animals, while the PC had lower spermatids and ESR. The concentration of estradiol (EST) was lower (p<0.05) in the PC and T2, while leuteinizing hormone (LH) concentration was lower (p<0.05) in the PC, and comparable (p>0.05) between control and T2. The concentration of follicle-stimulating hormone (FSH) was comparable (p>0.05) in all groups, while testosterone (TS) hormone concentration was lower (p<0.05) in the PC and higher in the control and T1 groups.

CONCLUSION

This study showed the preventive effects of NS administration against alterations in reproductive hormnes, sperm parameters and gonadal histology caused by LA in rats.

Role of low exposure to metals as male reproductive toxicants

The objective of the study was to examine the associations between environmentally relevant low metal concentrations and semen quality parameters in men. The concentrations of zinc (Zn), copper (Cu), cadmium (Cd), arsenic (As), selenium (Se), and lead (Pb) in the seminal plasma and urine were measured from 196 male human subjects in Taiwan. Urinary Cd concentrations were negatively associated with sperm viability (p = 0.006). Seminal plasma Cu concentrations of the normal group (≥ 15 × 10(6)/ml) were significantly lower than those of the abnormal group (p = 0.023). However, the linear regression analysis showed a weak association between Cu concentration and sperm concentration, along with other semen parameters. No significant relationship between other metals (As, Pb, Zn, and Se) and semen quality was observed.

Thymoquinone supplementation ameliorates lead-induced testis function impairment in adult rats

This study was realized to investigate the possible beneficial effect of thymoquinone (TQ), the major active component of volatile oil of Nigella sativa seeds, against lead (Pb)-induced inhibition of rat testicular functions. Adult rats were randomized into four groups: a control group receiving no treatment; a Pb group exposed to 2000 parts per million (ppm) of Pb acetate in drinking water; a Pb-TQ group co-treated with Pb (as in Pb group) plus TQ (5 mg/kg body weight (b.w.)/day, per orally (p.o.)); and a TQ group receiving TQ (5 mg/kg b.w./day, p.o.). All treatments were for 5 weeks. No significant differences were observed for the body weight gain or for relative testes weight among the four groups of animals. Testicular Pb content significantly increased in metal-intoxicated rats compared with that in control rats. TQ supplementation had no effect on this testicular Pb accumulation. Interestingly, when coadministrated with Pb, TQ significantly improved the low plasma testosterone level and the decreased epididymal sperm count caused by Pb. In conclusion, the results suggest, for the first time, that TQ protects against Pb-induced impairment of testicular steroidogenic and spermatogenic functions. This study will open new perspectives for the clinical use of TQ in Pb intoxication.

Improvement of mercuric chloride-induced testis injuries and sperm quality deteriorations by Spirulina platensis in rats

The present study was undertaken to investigate the protective effect of the filamentous cyanobacterium Spirulina platensis (S. platensis) on mercury (II) chloride (HgCl(2))-induced oxidative damages and histopathological alterations in the testis of Wistar albino rats. The animals were divided into four equal groups, i) control, ii) HgCl(2), iii) S. platensis and iv) combination of HgCl(2)+S. platensis. Oxidative stress, induced by a single dose of HgCl(2) (5 mg/kg, bw; subcutaneously, s.c.), substantially decreased (P<0.01) the activity level of testicular key enzymatic antioxidant biomarkers (superoxide dismutase, SOD; catalase, CAT and glutathione peroxidase, GPx), oxidative stress makers (blood hydroperoxide; testicular reduced glutathione, GSH and malondialdehyde, MDA), and testicular mercury levels. Moreover, HgCl(2) administration resulted in a significant (P<0.01) increase in the number of sperms with abnormal morphology and decrease in epididymal sperm count, motility, plasma testosterone level and testicular cholesterol. Furthermore, HgCl(2) exposure induced histopathological changes to the testis including morphological alterations of the seminiferous tubules, and degeneration and dissociation of spermatogenic cells. Notably, oral pretreatment of animals with Spirulina (300 mg/kg, bw) lowered the extent of the observed HgCl(2)-mediated toxicity, whereby significantly reducing the resulting lipid peroxidation products, mercury accumulation in the testis, histopathological changes of the testes and spermatozoal abnormalities. In parallel, the pretreatment with Spirulina also completely reverted the observed Hg-Cl(2)-induced inhibition in enzymatic activities of antioxidant biomarkers (SOD, CAT and GPx) back to control levels. The pretreatment of rats with S. platensis significantly recovered the observed HgCl(2)-mediated decrease in the weight of accessory sex organs. Taken together, our findings clearly highlight the role of S. platensis as a protective modulator of HgCl(2)-induced testicular injuries and suggest some therapeutic potential in mammals. Further investigation of therapeutic strategies employing Spirulina against heavy metals toxicity in humans is therefore warranted.

Lead level in seminal plasma may affect semen quality for men without occupational exposure to lead

BACKGROUND

Infertility affects approximately 10-15% of reproductive-age couples. Poor semen quality contributes to about 25% of infertile cases. Resulting from the direct effect on testicular function or hormonal alterations, heavy metals exposure has been related to impaired semen quality. The objective of this study was to assess the level of lead in the seminal plasma in men without occupational exposure to lead, and to determine the relationship between semen quality and lead concentration in the semen.

METHODS

This is a prospective and nonrandomized clinical study conducted in University infertility clinic and academic research laboratory. Three hundred and forty-one male partners of infertile couples undergoing infertility evaluation and management were recruited to the study. Semen samples collected for the analyses of semen quality were also used for the measurement of lead concentrations. Semen samples were evaluated according to the WHO standards.

RESULTS

All subjects were married and from infertile couples without occupational exposure to lead. There is a significant inverse correlation between the lead concentration in seminal plasma and sperm count. A higher semen lead concentration was correlated with lower sperm count, but not with semen volume, sperm motility or sperm morphology as assessed by simple linear regression.

CONCLUSIONS

We found that semen lead concentration was significantly higher among the patients with lower sperm count. To our knowledge, this is the first study to demonstrate that a high level of lead accumulation in semen may reduce the sperm count contributing to infertility of men without occupational exposure to lead.

Semen quality and reproductive endocrinal function related to blood lead levels in infertile painters

Lead causes male reproductive impairment among painters, but information is still limited. Therefore, the effect of lead on semen quality and reproductive endocrinal function in those patients was investigated. A case series of 27 infertile painters were subjected to semen analysis, measuring of blood lead level (PbB) and serum levels of endocrinal parameters including follicle-stimulating hormone (FSH), luteinising hormone (LH), testosterone (T) and prolactin (PRL). Significantly lower sperm count and motility were found in those with duration of exposure (≥ 15 years), but no significant difference was found for PbB and serum levels of FSH, LH, PRL and T. A significant negative correlation between PbB and spermatic count and motility was observed, while there was no significant correlation between PbB and all endocrinal parameters. Patients with PbB ≥ 20 μg dl(-1) showed a significant decrease in sperm motility and increase in testosterone alone among all measured hormones. But the observed decrease in sperm count did not reach a significant level. It is concluded that infertile painters are at risk of lead-related influence on semen quality, especially sperm motility and increased testosterone level without significant affection of other reproductive endocrinal parameters.

The protective effect of flaxseed oil on lead acetate-induced renal toxicity in rats

Lead is a toxic metal inducing many destructive effects leading to a broad range of physiological, biochemical, and neurological dysfunctions in humans. Here, we investigated the effects of flaxseed oil (1000 mg/kg) on the outcome of renal cytotoxicity induced by lead acetate (20mg/kg) in male rats. Lead induced injury of the renal tissue. This was evidenced (i) as increases in lead concentration in the kidney, (ii) as increases in the histopathological damage of the renal tissue, (iii) as increases in uric acid, urea and creatinine, (iv) as increases in lipid peroxidation, nitric oxide and reactive oxygen species, and (v) as lowered glutathione levels and decreased activities of catalase and superoxide dismutase, glutathione reductase, glutathione-S-transferase, and glutathione peroxidase, respectively. All these lead-induced parameters were significantly altered during flaxseed oil treatment. Therefore, our study suggests the role of flaxseed oil in limiting renal cytotoxicity-induced by lead acetate as a model for lead toxicity.