There are many discrepancies among the results of studies on the genotoxicity of lead. The aim of the study was to explore lead-induced DNA damage, including oxidative damage, in relation to oxidative stress intensity parameters and the antioxidant defense system in human leukocytes. The study population consisted of 100 male workers exposed to lead. According to the blood lead (PbB) levels, they were divided into the following three subgroups: a group with PbB of 20–35 μg/dL (low exposure to lead (LE) group), a group with a PbB of 35–50 µg/dL (medium exposure to lead (ME) group), and a group with a PbB of >50 μg/dL (high exposure to lead (HE) group). The control group consisted of 42 healthy males environmentally exposed to lead (PbB < 10 μg/dL). A comet assay was used to measure the DNA damage in leukocytes. We measured the activity of superoxide dismutase (SOD), catalase, glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), and glutathione-S-transferase (GST) as well as the concentration of malondialdehyde (MDA), and the value of the total antioxidant capacity. The level of PbB was significantly higher in the examined subgroups than in the control group. The percentage of DNA in the tail was significantly higher in the LE, ME, and HE subgroups than in the control group by 10% (p = 0.001), 15% (p < 0.001), and 20% (p < 0.001), respectively. The activity of GR was significantly lower in the LE and ME subgroups than in the control group by 25% (p = 0.007) and 17% (p = 0.028), respectively. The activity of G6PD was significantly lower in the ME subgroup by 25% (p = 0.022), whereas the activity of GST was significantly higher in the HE subgroup by 101% (p = 0.001) than in the control group. Similarly, the activity of SOD was significantly higher in the LE and ME subgroups by 48% (p = 0.026) and 34% (p = 0.002), respectively. The concentration of MDA was significantly higher in the LE, ME, and HE subgroups than in the control group by 43% (p = 0.016), 57% (p < 0.001), and 108% (p < 0.001), respectively. Occupational lead exposure induces DNA damage, including oxidative damage, in human leukocytes. The increase in DNA damage was accompanied by an elevated intensity of oxidative stress.

Infertility is among the most serious medical problems worldwide. Male factors contribute to 40%–50% of all infertility cases, and approximately 7% of men worldwide are affected by infertility. Spermatozoa are extremely vulnerable to oxidative insult. Oxidative stress results in axonemal damage and increased midpiece sperm morphological defects, which lead to reduced sperm motility. The aim of the study is to evaluate the association between sperm motility and the levels of selected antioxidants, cytokines, and markers of oxidative damage in the seminal plasma. The study group included 107 healthy males, who were split into two subgroups based on the percentage of motile spermatozoa after 1 hr: low motility (LM, n = 51) and high motility (HM, n = 56). The glucose-6-phosphate dehydrogenase (G6PD) activity was 52% lower in the LM group compared to that in the HM group. The level of malondialdehyde (MDA) was 12% higher in the LM group compared to that in the HM group. Similarly, the median values of interleukin (IL)-1β, IL-10, IL-12, and tumor necrosis factor alpha (TNF-α) were higher in the LM group than those in the HM group. Results of the present study revealed that the percentage of motile spermatozoa after 1 hr correlated positively with the levels of IL-1β, IL-10, IL-12, and TNFα. The lower motility of spermatozoa in healthy men is associated with a decreased activity of G6PD and increased levels of cytokines, which may be related to increased oxidative stress in seminal plasma that manifests as an increased level of MDA.

The aim of the study was to evaluate the parameters of oxidative stress and antioxidant defense in relation to the levels of proinflammatory cytokines and chemokines in patients diagnosed with oligozoospermia and asthenozoospermia. Based on the basic parameters of the spermogram, the examined group (n= 243) was divided into three groups: oligospermic group (sperm count less than 15 × 10⁶/ml) consisting of 152 men, astenozoospermic group (less than 40% of progressively moving sperm cells) consisting of 142 men, and oligoastenozoospermic group (both criteria met) consisting of 90 men. The control group consisted of 103 males with normal semen profile according to the WHO criteria. Total superoxide dismutase (SOD) activity in seminal plasma and spermatozoa lysate was significantly lower by 12% and 22%, respectively, in males with oligospermia than in the control group. Analogically, Mn‐SOD activity in spermatozoa lysate was significantly lower in males with oligospermia, asthenospermia, and oligoasthenospermia by 44%, 32%, and 45%, respectively. By contrast, CuZn‐SOD activity in spermatozoa lysate was significantly higher in males with oligospermia by 60%. The activity of glutathione peroxidase (GPx) in seminal plasma was also significantly higher in males with oligospermia and oligoasthenospermia by 56% and 78%, respectively. The level of malondialdehyde (MDA) in seminal plasma was significantly higher in males with asthenospermia than in the control group by 12%. By contrast, the level of MDA in spermatozoa lysate was significantly lower in males with oligospermia, asthenospermia, and oligoasthenospermia by 26%, 20%, and 26%, respectively. The level of interleukin‐ (IL‐) 8 in seminal plasma was significantly higher in males with asthenospermia and oligoasthenospermia by 64% and 67%, respectively. Abnormalities in spermogram, such as oligospermia, asthenospermia, and oligoasthenospermia, may be related to a decreased activity of Mn‐SOD in spermatozoa and increased levels of chemokines in seminal plasma.

The aim of the study was to determine the effect of occupational exposure to lead on the blood levels of pro-inflammatory cytokines and selected factors that influence angiogenesis. The study population was divided into two groups. The first group consisted of 56 male workers chronically exposed to lead. The second group (control) was comprised of 24 male administrative workers. The serum levels of interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were significantly higher in the group of workers chronically exposed to lead compared to control values by 38%, 68%, and 57%, respectively. Similarly, the values of soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) and fibroblast growth factor-basic (FGF-basic) were higher by 19% and 63%, respectively. In the group of workers chronically exposed to lead, there were positive correlations between the levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and angiogenic factors (VEGF, FGF-basic, sVEGFR-1, and soluble angiopoietin receptor). In the control group, there were no correlations between the levels of the abovementioned parameters. Results of the present study indicate that chronic occupational lead exposure promotes inflammatory processes via induction of pro-inflammatory cytokines, modulates angiogenesis, and elicits interdependencies between the immune response and angiogenic factors.

Many investigators have posited on the significant influence of lead on the immune system function. However, available data on this topic are not conclusive. Therefore, a study was undertaken to examine associations between lead exposure and levels of cytokines related to the T-helper (T_H)-1, T_H2, and T_H17 types of immune response in humans. For these analyses, three population groups were examined: the first consisted of male workers exposed to lead for a short period of time (36–44 days); the second included male workers chronically exposed to lead (13 ± 10 years); and a control group that was composed of male administrative workers with blood lead levels (BLL) < 10 μg/dl. BLL were determined for all study subjects. Thereafter, serum samples were analyzed for the levels of interleukin (IL)-2 (IL-2), IL-4, IL-5, IL-12, IL-13, IL-17A, and interferon (IFN)-γ using a multi-analyte system. The results indicated that the levels of IFNγ IL-2, IL-12 (related to T_H1 cells), IL-4, IL-5, IL-13 (related to T_H2 cells), and IL-17A (related to T_H17 cells) did not change after a short-term exposure to lead (compared to baseline). However, the levels of all of these cytokines were significantly higher in workers chronically exposed to lead than in the controls by 82%, 32%, 81%, 22%, 70%, 42%, and 17% (IFNγ, IL-2, IL-12, IL-4, IL-5, IL-13, IL-17A, respectively). From these studies, we conclude that in humans, a short-term exposure to lead does not affect levels of cytokines related to the T_H1-, T_H2-, and T_H17-mediated immune responses, while chronic exposure modifies their levels. Taken together, these modifications do not evidence an ability of lead to promote specifically one type of immune response in an exposed host.

The aim of the study was to investigate the associations between standard semen parameters and the parameters reflecting oxidative stress intensity, antioxidant defense functions, levels of selected macro and trace elements, and parameters characterizing immune system function. The study group consisted of 103 fertile males. Based on semen volume, sperm concentration, total sperm count, and percentage of motile sperm at 1 hour postcollection, the individuals were divided into two equal groups—those with excellent (EX) semen quality and those with mediocre (ME) semen quality. The remaining measured parameters characterizing motility and the percentage of normal morphology were higher in the EX group than in the ME group; however, the seminal plasma pH did not differ between the examined groups. The phosphate level was 31% lower in the EX group than in the ME group, whereas there was a tendency toward a 25% lower level of Fe in the EX group than in the ME group (p= 0.064). The activities of enzymes involved in antioxidant defense, CuZn‐SOD, CAT, and G6PD, were 14%, 63%, and 39%, respectively, higher in the EX group than in the ME group. However, the level of alpha‐tocopherol was 32% lower in the EX group than in the ME group. The other measured parameters characterizing antioxidant defense and the parameters of oxidative stress intensity and immune system function were not significantly different. The value of seminal plasma pH is not related to the semen quality of fertile males. Higher fertility potential estimated based on standard semen parameters in fertile males is associated with lower levels of Fe and higher activities of some antioxidant enzymes.