Subchronic exposure to lead acetate inhibits spermatogenesis and downregulates the expression of Ddx3y in testis of mice

Involvement of toxic metals and PCBs mixture in the thyroid and male reproductive toxicity: In silico toxicogenomic data mining

Toxicological research is mostly limited to considering the effects of a single substance, even though the real exposure of people is reflected in their daily exposure to many different chemical substances in low-doses. This in silico toxicogenomic study aims to provide evidence for the selected environmental (organo)metals (lead, cadmium, methyl mercury) + polychlorinated biphenyls mixture involvement in the possible alteration of thyroid, and male reproductive system function, and furthermore to predict the possible toxic mechanisms of the environmental cocktail. The Comparative Toxicogenomic Database, GeneMANIA online software, and ToppGene Suite portal were used as the main tools for toxicogenomic data mining and gene ontology analysis. The results show that 35 annotated common genes between selected chemicals and endocrine system diseases can interact on the co-expression level. Our study highlighted the disruption of the cytokines, the cell's response to oxidative stress, and the influence of the transcription factors as the potential core of toxicological mechanisms of the discussed mixture's effects. The connected toxicological effects of the tested mixture were abnormal sperm cells, a disrupted level of testosterone, and thyroid hormones. The core mechanisms of these effects were inflammation, oxidative stress, disruption of androgen receptor signaling, and the alteration of the FOXO3-Keap-1/NRF2-HMOX1-NQO1 pathway signaling most likely controlled by the co-expression of overlapped genes among used chemicals. This in silico research can be used as a potential core for the determination of biomarkers that can be monitored in future further in vitro and in vivo experiments.

Lead Exposure Assessment and Its Impact on the Structural Organization and Morphological Peculiarities of Rat Ovaries

Lead is known to be highly toxic to humans, causing various disorders infetal development. An experiment was conducted to examine the effects of lead acetate on the structural organization of female rat ovaries. The study involved 40 non-linear female rats divided into four groups: a control group, a low-dose group, a moderate-dose group, and a high-dose group. The rats were given lead acetate solutions in varying doses for 30 days, and their ovarian tissue was examined using light microscopy.The results showed that increasing doses of lead acetate led to morphological changes in the cortex and medulla of the rat ovaries. The changes were characterized by a decrease in ovarian mass, alterations in the thickness of the tunica albuginea (protein envelope), and a reduction in the number of follicles. Light microscopy revealed that exposure to lead acetate resulted in a significant decrease in the number of follicles in all experimental groups, with the high-dose group experiencing the most significant decrease.These findings suggest that lead acetate has a dose-dependent negative impact on the morphology and function of female rat ovaries. Further studies are needed to investigate the potential impact of lead on human ovarian tissue.

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

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

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Quercetin Abates Aluminum Trioxide Nanoparticles and Lead Acetate Induced Altered Sperm Quality, Testicular Oxidative Damage, and Sexual Hormones Disruption in Male Rats

This study examined the effects of exposure to lead acetate (PbAc) and/or aluminum trioxide nanoparticles (Al₂O₃NPs) on testicular function. Additionally, the probable reproprotective effects of quercetin (QTN) against Al₂O₃NPs and PbAc co-exposure in male Sprague Dawely rats were assessed. Al₂O₃NPs (100 mg/kg b.wt.), PbAc (50 mg/kg b.wt.), and QTN (20 mg/kg b.wt.) were orally administered for 60 days. Then, spermiogram, histopathological examinations of the testis and accessory glands, and immunohistochemical detection of androgen receptors (AR) and tumor necrotic factor alpha (TNF-α) were achieved. Moreover, serum levels of male sex hormones and testicular levels of antioxidant indices were estimated. The results showed that Al₂O₃NP_s and/or PbAc caused significant sperm abnormalities, testicular oxidative stress, and histopathological changes. Furthermore, serum testosterone, LH, and FSH levels significantly decreased, while estradiol levels significantly increased. The Al₂O₃NPs and/or PbAc co-exposed group had more obvious disturbances. Furthermore, QTN co-administration significantly reversed the Al₂O₃NPs and PbAc-induced testicular histopathological alterations, reduced antioxidant defenses, and altered AR and TNF-α immune expression in testicular tissues. Conclusively, Al₂O₃NPs and/or PbAc evoked testicular dysfunction by inducing oxidative injury and inflammation. However, QTN oral dosing effectively mitigated the negative effects of Al₂O₃NPs and PbAc by suppressing oxidative stress and inflammation and improving the antioxidant defense system.

AMPK pathway is implicated in low level lead-induced pubertal testicular damage via disordered glycolysis

Lead (Pb) is a common environmental pollutant. It has been demonstrated that long-term exposure to Pb at environmental levels may cause severe and irreversible damage to the male reproductive system. Of note, the impairments may originate from environmental Pb exposure at puberty. However, the underlying mechanisms remain unclear. In this study, we administrated male ICR mice with 200 mg/L Pb through the drinking water for 30-, 60-, 90-day from postnatal day 28. RNA sequencing was performed in the control group and the 90-day Pb exposure group. It was found that Pb exposure induced testicular damage, increased oxidative stress levels and poor sperm quality. Bioinformatic analysis displayed 199 genes up-regulated (such as GLUT1 and MCT4 genes) and 156 genes down-regulated (such as GLUT3, PFK1, LDH, CD147 and AMPK genes) in the Pb exposure group compared to the control group. Gene ontology (GO) terms enrichment analysis showed differentially expressed genes (DEGs) are involved in the protein catabolic, cellular catabolic and triglyceride catabolic processes. KEGG pathways enrichment analysis indicated glycerolipid metabolism and AMPK signaling were significantly enriched. Furthermore, experimental verification showed that Pb exposure induces energy dysmetabolism and decreases glycolysis products in mice testicular tissue. The AMPK signaling pathway was found to be deactivated after Pb exposure. The GLUT1, GLUT3, PFK1 and LDH proteins, which play a critical role in the cell glycolysis process, also were decreased. Besides, the expression of CD147 was decreased and the location of CD147 was altered upon Pb exposure. Together, these findings indicated the implication of the AMPK signaling pathway in Pb exposure induced pubertal testicular damage and poor sperm quality by inhibiting cell glycolysis and disordering lactate transportation in testicular cells.

Counteracting effects of heavy metals and antioxidants on male fertility

Infertility is regarded as a global health problem affecting 8-12% of couples. Male factors are regarded as the main cause of infertility in 40% of infertile couples and contribute to this condition in combination with female factors in another 20% of cases. Abnormal sperm parameters such as oligospermia, asthenospermia, and teratozoospermia result in male factor infertility. Several studies have shown the deteriorative impact of heavy metals on sperm parameters and fertility in human subjects or animal models. Other studies have pointed to the role of antioxidants in counteracting the detrimental effects of heavy metals. In the currents study, we summarize the main outcomes of studies that assessed the counteracting impacts of heavy metal and antioxidants on male fertility. Based on the provided data from animal studies, it seems rational to administrate appropriate antioxidants in persons who suffer from abnormal sperm parameters and infertility due to exposure to toxic elements. Yet, further human studies are needed to approve the beneficial effects of these antioxidants.

The effects of chronic lead exposure on the ovaries of female juvenile Japanese quails (Coturnix japonica): Developmental delay, histopathological alterations, hormone release disruption and gene expression disorder

Lead (Pb) is well-recognized for its great hazards to human and wildlife health. It has negative influences on multiple organs and systems of birds. Especially, lead exposure caused adverse impacts on bird reproduction. In this study, one week old female Japanese quails were randomly allocated into four groups and each group was respectively fed with 0, 50 ppm, 500 ppm and 1000 ppm Pb in drinking water for 36 days to determine the effects of chronic lead exposure on ovarian development and function. The results showed that Pb did accumulate in the ovary and ovarian development was delayed by high dose lead exposure (500 ppm and 1000 ppm). Moreover, high Pb dosage induced ovarian histopathological damages characterized by granulosa cells disorganization, follicle atresia and interstitial cell degeneration. Meanwhile, the concentration of estradiol (E2) was significantly decreased and mRNA levels of genes involved with ovarian steroidogenesis were significantly down-regulated by high concentration Pb. In addition, Pb exposure caused increasing cell apoptosis and significant changes of the expression of genes involved with cell death in the ovary. High dose Pb exposure also inhibited thyroid hormone release and disrupted ovarian thyroid deiodination apart from causing thyroid histopathological injury such as follicular deformation and atrophy. The study indicated that Pb might cause ovarian malfunction by inducing ovary and thyroid microstructural damages, thyroid hormone and estrogen release inhibition and ovarian steroidogenesis disruption.

Individual and combined toxicogenetic effects of microplastics and heavy metals (Cd, Pb, and Zn) perturb gut microbiota homeostasis and gonadal development in marine medaka (Oryzias melastigma)

Currently, microplastics (MPs) attracted increased attention for their ubiquity and toxic properties. In this study, marine medaka was used to explore the individual and combined toxicity of heavy metals (HMs) and MPs on intestinal bacteria and gonadal development. After exposure to environmentally relevant concentrations of MPs and HMs, significant alterations of intestinal microbiota were found. The MPs treatment reduced the diversity and abundance of intestinal microbiota, while the HMs and MPs-HMs treatments increased them, which were confirmed by the abundance changes of Proteobacteria. According to the KEGG analysis, the metabolism and environmental information processing (EIP) pathways in the microbial community were significantly affected. This study showed that the MPs-HMs treatment caused a higher pollution load on the gut of the marine medaka, and triggered more significant changes of specific bacterial species and gut function in the males. However, during the gonadal development, HMs and MPs-HMs treatments resulted in empty follicles (EF) and follicular atresia (FA), and altered the gene expression levels related to hypothalamic-pituitary-gonadal (HPG) axis. In short, this study demonstrated that the reproductive disturbance was mainly due to HMs, but the combination of MPs and HMs did not strengthen the risk to the gonad development of the marine medaka.

Protective effect of betaine against lead-induced testicular toxicity in male mice

Lead (Pb) is an environmental toxicant reported to impair male reproductive system. Betaine is a natural product which has promising beneficial effects against oxidative stress. In this experimental study, we evaluated the ameliorative effect of betaine on sperm quality and oxidative stress induced by lead (Pb) in the testis of adult male mice. Sixty male Kunming mice were divided equally into four groups: control group, betaine group (1% in drinking water), lead group (100 mg kg^-1  bw^-1  day^-1 ) and betaine + lead group. In the last group, mice were supplemented with betaine for two weeks prior to the initiation of lead treatment and concurrently during lead treatment for 3 weeks until sacrificed. Our results indicated that in the lead-administrated group, body weights together with sperm count were significantly decreased (p < .05). The numbers of abnormal sperms were found to be higher in lead-treated mice. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (Cat) were significantly reduced, while the level of malondialdehyde (MDA) content was increased in the testis tissue following lead treatment. The mRNA levels of antioxidant-related genes (SOD1, GPX1 and CAT) were significantly decreased in the lead group. Betaine enhanced these parameters in betaine + lead group. In testis histology span, Johnson score was decreased (p < .05) in lead group and co-treatment with betaine increased Johnson score significantly in betaine + lead group. These results indicate that betaine improves sperm quality and ameliorate oxidative damage in testis of mice exposed to lead.

Low dose lead exposure at the onset of puberty disrupts spermatogenesis-related gene expression and causes abnormal spermatogenesis in mouse

Implications of lead (Pb) exposure in dysregulated spermatogenesis in sexually active individuals during adulthood is well established; however, the effect of Pb exposure on spermatogenesis in the early stages of puberty is not clear yet. Moreover, the mechanism of Pb mediated dysregulation of spermatogenesis in adults is also poorly understood. Exposure to environmental toxicants during puberty may cause serious consequences in adulthood causing developmental retardations, especially in the reproductive system. Here we investigated the effects of lead exposure on spermatogenesis at the onset of puberty and the underlying mechanisms of these effects. Male ICR mice were exposed to low (50 mg/L) and high (200 mg/L) doses of Pb through the drinking water for 90 days. At the end of this period, the blood Pb level of the low-dose and high-dose exposure groups were found 6.14 ± 0.34 μg/dL and 11.92 ± 2.92 μg/dL respectively which were in agreement with the US CDC-recommended (5 μg/dL) and Chinese CDC-recommended (10 μg/dL) reference blood Pb level for the children. Although no visible toxicity was observed in either group, Pb exposure caused considerable histopathological changes in testis and epididymis; increased sperm DNA fragmentation indices as well as disrupted sperm heads and head-neck conjunctions. Moreover, both low and high-dose Pb exposures caused aberrant expressions of several important spermatogenesis-related genes in epididymis and testis. These results suggest that although the blood Pb levels are close to the recommended-reference values, low dose Pb exposure at the onset of puberty can disrupt spermatogenesis-related gene expression and cause abnormal mouse spermatogenesis.

Low concentrations of lead decrease the sperm fertilization ability by altering the acrosome reaction in mice

Lead (Pb) exposure at high concentrations is associated with poor sperm quality, acrosome alterations, and low fertilization rate. Sperm capacitation and the acrosome reaction (AR) are required for successful fertilization. Actin polymerization is crucial for correct capacitation, and small GTPases, such as RhoA, Rac1, and Cdc42, are involved. This study aimed to evaluate the effects of Pb on sperm fertilization ability, capacitation, AR, and the mechanisms involved in mice exposed to low Pb concentrations. CD1 mice were exposed to 0.01% Pb²⁺ for 45 days through their drinking water and their spermatozoa were collected from the cauda epididymis-vas deferens to evaluate the following: AR (oAR: initial, sAR: spontaneous, and iAR: induced) using the PNA-FITC assay, sperm capacitation (P-Tyr levels), actin polymerization (phalloidin-TRITC), MDA production (stress oxidative marker), the RhoA, Rac1, and Cdc42 protein levels, and the in vitro fertilization (IVF). After the treatment, the blood Pb (PbB) concentration was 9.4 ± 1.6 μg/dL. Abnormal sperm morphology and the oAR increased (8 and 19%, respectively), whereas the iAR decreased (15%) after a calcium ionophore challenge, and the actin polymerization decreased in the sperm heads (59%) and tails (42%). Rac1 was the only Rho protein to significantly decrease (33%). Spermatozoa from the Pb-treated mice showed a significant reduction in the fertilization rate (19%). Our data suggest that Pb exposure at environmental concentrations (PbB < 10 μg/dL) decreases the acrosome function and affects the sperm fertilization ability; this is probably a consequence of the low Rac1 levels, which did not allow adequate actin polymerization to occur.

Effect of heavy metals arsenic, cadmium, and lead on the semen variables of dromedary camels (Camelus dromedarius)

In this study, there was investigation of the effect of heavy metals on the fertility of dromedary camels. Fourteen camels at the Camel Research Center, King Faisal University, and 41 infertile dromedaries admitted to the Veterinary Teaching Hospital were used for semen evaluation during the breeding season. Seminal plasma and blood serum were collected from all males until analysis. Concentrations of three heavy metals [arsenic (As), cadmium (Cd), and lead (Pb)] were determined in the seminal plasma and serum using an atomic absorption spectrophotometer. The results indicate there are differences (P <  0.05 - P < 0.01) in pH, sperm motility, sperm concentration, and sperm abnormalities between the fertile and infertile male camels. In seminal plasma, there were marked differences (P < 0.01- P < 0.0001) between the control and infertile male camels in As, Cd, and Pb concentrations. In serum, there were differences (P <  0.01 - P <  0.001) between the fertile and infertile camels in serum As, Cd, and Pb concentrations. There was a positive correlation (P <  0.05; r = 0.77 and r = 0.94, respectively) between serum and seminal plasma concentrations of both As and Cd in the infertile dromedaries. In the control group, there was a positive correlation (P <  0.05; r = 0.70) between seminal plasma concentrations of Cd and percent sperm abnormalities. In conclusion, relatively greater seminal plasma and serum concentrations of As, Cd, and Pb are associated with lesser values for semen quality variables and infertility in dromedary camels.

Targeting RNA helicase DDX3 in stem cell maintenance and teratoma formation

DDX3 is an RNA helicase that has antiapoptotic properties, and promotes proliferation and transformation. Besides the role of DDX3 in transformed cells, there is evidence to indicate that DDX3 expression is at its highest levels during early embryonic development and is also expressed in germ cells of adults. Even though there is a distinct pattern of DDX3 expression during embryonic development and in adults, very little is known regarding its role in embryonic stem cells and pluripotency. In this work, we examined the relationship between DDX3 and human embryonic stem cells and its differentiated lineages. DDX3 expression was analyzed by immunohistochemistry in human embryonic stem cells and embryonal carcinoma cells. From the data obtained, it was evident that DDX3 was overexpressed in undifferentiated stem cells compared to differentiated cells. Moreover, when DDX3 expression was abrogated in multiple stem cells, proliferation was decreased, but differentiation was facilitated. Importantly, this resulted in reduced potency to induce teratoma formation. Taken together, these findings indicate a distinct role for DDX3 in stem cell maintenance.

Reduced testosterone and Ddx3y expression caused by long-term exposure to arsenic and its effect on spermatogenesis in mice

Arsenic (As) has been recognized as a cause of male reproductive toxicity. However, effects of long-term arsenic exposure (puberty-adult) on spermatogenesis, testosterone synthesis, and the expression of androgen binding protein (ABP) and Ddx3y remain unclear. The objective of this investigation was to explore these effects and the underlying mechanisms. Male mice were treated with 5 and 50 ppm arsenic for 6 months via drinking water. The results showed that arsenic reduced sperm count and sperm motility and enhanced the abnormal sperm percentage. The decrease in the number of spermatogenic cells and sperm in seminiferous tubules and the decline in the Johnsen score were observed in both arsenic-treated groups, suggesting spermatogenesis disorders. Moreover, arsenic diminished serum testosterone, along with the reduced expression of luteinizing hormone receptor (LHR), steroidogenic acute regulatory protein (StAR) and 17-β-hydroxysteroid dehydrogenase (17β-HSD) genes. Arsenic also down-regulated mRNA levels of ABP and Ddx3y in a dose-dependent manner. Meanwhile, the protein levels of StAR, 17β-HSD and Ddx3y were significantly reduced in arsenic-treated groups. Taken together, these results suggest that the reduced testosterone through inhibition of the expression of multiple genes responsible for the biosynthesis, the damaged androgen homeostasis partially via lessening the expression levels of the ABP gene and the down-regulated expression of Ddx3y, may contribute to spermatogenesis disorders in mice exposed to arsenic.

Acupuncture Alleviates Levodopa-Induced Dyskinesia via Melanin-Concentrating Hormone in Pitx3-Deficient aphakia and 6-Hydroxydopamine-Lesioned Mice

Although L-3,4-dihydroxyphenylalanine (L-DOPA) is currently the most effective medication for treating Parkinson's disease (PD) motor symptoms, its prolonged administration causes several adverse effects, including dyskinesia. To identify the mechanisms underlying the effects of acupuncture on L-DOPA-induced dyskinesia (LID), antidyskinetic effects of acupuncture were investigated in two mouse models of PD. Acupuncture stimulation at GB34 alleviated abnormal involuntary movements (AIMs) in Pitx3-deficient aphakia mice (ak/ak) following L-DOPA administration and these effects were reproduced in 6-hydroxydopamine (6-OHDA)-lesioned mice with LID. A transcriptome analysis of the hypothalamus revealed pro-melanin-concentrating hormone (Pmch) gene was highly expressed in acupuncture-treated mouse from ak/ak model of LID as well as 6-OHDA model of LID. Acupuncture combined with the administration of MCH receptor antagonist did not have any beneficial effects on dyskinesia in L-DOPA-injected ak/ak mice, but the intranasal administration of MCH attenuated LID to the same degree as acupuncture in both ak/ak and 6-OHDA mice with LID. A gene expression profile with a hierarchical clustering analysis of the dyskinesia-induced ak/ak mouse brain revealed an association between the mechanisms underlying acupuncture and MCH. Additionally, altered striatal responses to L-DOPA injection were observed after prolonged acupuncture and MCH treatments, which suggests that these treatment modalities influenced the compensatory mechanisms of LID. In summary, present study demonstrated that acupuncture decreased LID via hypothalamic MCH using L-DOPA-administered ak/ak and 6-OHDA mouse models and that MCH administration resulted in novel antidyskinetic effects in these models. Thus, acupuncture and MCH might be valuable therapeutic candidates for PD patients suffering from LID.

Down-regulation of CatSper 1 and CatSper 2 genes by lead and mercury

In the study of the expression of CatSper genes, consideration of the effects of environmental metal toxicity is very important. Therefore, in this study, the effects of lead acetate and mercury chloride exposure on expression of CatSper genes, sperm parameters, histology of testis and prooxidant antioxidant balance (PAB) values of serum were investigated. A total of 28 mice was divided into four groups. The control group did not receive injections. The sham group received normal saline intraperitoneally. Lead and mercury groups were injected 60 and 1.25 mg/kg/daily lead acetate and mercury chloride respectively intraperitoneally for 2 weeks. After 35 days, the sperm analysis and histology of left testis were performed. In addition, serum was obtained to measure the PAB values. The right testis was used for molecular analysis of real-time PCR. Administration with either lead acetate or mercury caused significant damage to the seminiferous tubules as well as a reduction in sperm parameters compared to the control group. The relative expression of CatSper 1 and CatSper 2 in the lead group was lower than that of the control group (-0.01 ± 0.24, -0.007 ± 0.52 vs. 1 ± 0.50, P = 0.34). The relative expression of CatSper 1 and CatSper 2 was significantly lower in the mercury group compared to the control ones (-0.24 ± 2.28, -4.49 ± 4.86 vs. 1 ± 0.50, P = 0.21). PAB values significantly increased in lead or mercury exposed- mice compared to the control ones (0.93 ± 0.17, 1.54 ± 0.17 vs. 0.51 ± 0.11; P ≤ 0.000). The results of this study showed that administration with either lead acetate or mercury chloride caused degenerative damage in seminiferous tubules and reduction in sperm quality and expression of CatSper 1, 2 genes in mice. Therefore, it is possible in infertile men who have had exposure to lead acetate or mercury chloride. Owing to structural similarities, these metals are substitutes for calcium ions and have effects on calcium channels. These cause immobility in sperm by blocking CatSper-specific calcium channels. However, more studies are required to elucidate the mechanism underlying the impact of different doses of heavy metals on CatSper genes expression.

Probit analysis of comparative assays on toxicities of lead chloride and lead acetate to in vitro cultured human umbilical cord blood lymphocytes

This work describes that cytotoxicity of lead chloride and lead acetate to in vitro cultured lymphocytes from human umbilical cord blood, using four monitoring methods namely, trypan blue staining, acridine orange/ethidium bromide staining, 3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyl tetrazolium bromide (MTT) and neutral red uptake assays; lead genotoxicity to lymphocytes was monitored by comet assay. The MIC value in each method was invariably 300 mg/L for PbCl₂. Lethal concentration₂₅ (LC₂₅) values were almost in an agreeable range: 691.83 to 831.76 mg/L; LC₅₀ values in each method were almost in the range: 1174.9 to 1348.9 mg/L; LC₁₀₀ values were in the range: 3000 to 3300 mg/L, for lead chloride. Similarly, The MIC value in each method were invariably 150 mg/L; LC₂₅ values were almost in the range: 295.12 to 371.53 mg/L; LC₅₀ values were in the range: 501.18 to 588.84 mg/L; LC₁₀₀ value was 1500 mg/L in all assays, for lead acetate. The comet assay also indicated that the LC₁₀₀ values were 3300 mg/L lead chloride and 1500 mg/L lead acetate. Thus, both cytotoxicity and genotoxicity were recorded at 3300 mg/L lead chloride and 1500 mg/L lead acetate with lymphocytes.