Relationship between lead absorption and iron status and its association with oxidative stress markers in lead-exposed workers

Exposure to a mixture of metal(loid)s and sleep quality in pregnant women during early pregnancy: A cross-sectional study

Biological characteristics of pregnant women during early pregnancy make them susceptible to both poor sleep quality and metal/metalloid exposure. However, the effects of metal(loid) exposure on sleep quality in pregnant women remain unknown and unexplored. We aimed to examine the relationship between exposure to a mixture of metal(loid)s and pregnant women's sleep quality during early pregnancy. We recruited 493 pregnant women in the first trimester from prenatal clinics in Jinan, Shandong Province, China, and collected their spot urine samples. All urine specimens were assessed for eight metal(loid)s: arsenic (As), cadmium (Cd), iron (Fe), zinc (Zn), molybdenum (Mo), lead (Pb), selenium (Se), and mercury (Hg). We used the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. Linear regression, logistic regression, generalized additive models (GAMs), quantile g-computation, and Bayesian kernel machine regression (BKMR) were applied to investigate the relationships between metal(loid) exposure and sleep quality. The results from single metal(loid) models, quantile g-computation models, and BKMR models consistently suggested that Fe was positively related to women's sleep quality. Moreover, in the quantile g-computation models, As was the most critical contributor to the negative effects of the metal(loid) mixture on sleep quality. In addition, we found significant As by Fe interaction for scores of PSQI and habitual sleep efficiency, Pb by Fe interaction for PSQI and sleep latency, and Hg by Fe interaction for PSQI, suggesting the interactive effects of As and Fe, Pb and Fe, Hg and Fe on sleep quality and specific sleep components. Our study provided the first-hand evidence of the effects of metal(loid) exposure on pregnant women's sleep quality. The underlying mechanisms need to be explored in the future.

Selenium and vitamin E ameliorate lead acetate-induced hepatotoxicity in rats via suppression of oxidative stress, mRNA of heat shock proteins, and NF-kB production

BACKGROUND

Lead exposure results in a terrible rise in heat shock protein levels.

OBJECTIVE

This research was conducted to look at the effects of lead poisoning on heat shock response, oxidative stress, and inflammatory markers in albino rats, as well as the power of selenium and vitamin E to resist lead toxic effects.

METHODS

Eight groups of albino rats are used. Each group contained six rats where the first group represented the negative control, and the other groups were treated with olive oil, vitamin E, selenium, lead, (vitamin E + lead), (selenium + lead), and (vitamin E + selenium + lead). All the treatments lasted for 28 days. Then, the mRNA expression of interested heat shock proteins (HSP90, HSP70, and HSP60) was assessed. For oxidative stress disruption, we investigated nitric oxide (NO) and malondialdehyde (MDA) content, and enzymatic and non-enzymatic antioxidants activity respectively in rat livers.

RESULTS

our results revealed the synergetic protective effect of the combination of two antioxidants (vitamin E and selenium) against lead poising. This was clear in regulating HSPs expression, inflammatory markers, glucose, lipid profile, liver functions, and antioxidant enzymes more than the treatment with one antioxidant.

CONCLUSION

Pb is a toxic material that can induce HSPs and inflammatory markers expression. Selenium and vitamin E can give excellent effects in ameliorating Pb toxicity when used together.

Lead (Pb) and cadmium (Cd) blood levels and potential hematological health risk among inhabitants of the claimed hazardous region around Qaroun Lake in Egypt

BACKGROUND

Lead (Pb) and cadmium (Cd) heavy metals are considered potentially hazardous toxins which cause serious health problems. Many studies reported that the water of Qaroun Lake in Fayoum, Egypt with its fish farms was contaminated with Pb and Cd above permissible levels. However, there is a lack of studies addressing levels of these toxic metals among inhabitants.

OBJECTIVES

We aimed to evaluate blood levels of Pb and Cd and their potential health risk among inhabitants around Qaroun Lake.

MATERIALS AND METHODS

This case-control study estimated Pb and Cd blood levels among 190 individuals from two destinations (near and far away) of Qaroun Lack using an atomic absorption spectrometer after full history taking and routine checkup investigations; Full blood count, serum ferritin, liver enzyme (ALT), and creatinine levels.

RESULTS

There was a significant difference between blood levels of Pb and Cd heavy metals of inhabitants from near and far away Qaroun Lake destinations (p-value < 0.001). The majority of inhabitants around Qaroun Lake had Pb and Cd blood levels above permissible levels (100% and 60% respectively). Critical levels out of them were 12.1% and 30.3% respectively. In comparison to inhabitants faraway Qaroun Lake, three individuals (2.4%) had Cd above the permissible level, while all of them (100%) had Pb level within the permissible level. There were no statistically significant differences between the two sampled populations as regards hemoglobin level, ALT, creatinine, and ferritin serum levels (p-value > 0.05). The difference between studied populations regarding types of anemia was not statistically significant. Subclinical leucopenia was higher in the population near Qaroun Lake when compare to inhabitants far from the lake (13.6% vs. 4.8%, p-value 0.032).

CONCLUSION

Bio-monitoring of populations exposed to Pb and Cd hazardous substances could help in generating an early warning system to reduce the disease burden associated with their toxicity.

Lead toxicity and potential therapeutic effect of plant-derived polyphenols

BACKGROUND

Due to its unique physical and chemical properties, lead is still used worldwide in several applications, especially in industry. Both environmental and industrial lead exposures remain a public health problem in many developing and rapidly industrializing countries. Plant polyphenols are pleiotropic in their function and have historically made a major contribution to pharmacotherapy.

PURPOSE

To summarize available pre-clinical and limited clinical evidence on plant polyphenols as potential antidotes against lead poisoning and discuss toxic mechanisms of lead.

METHOD

A comprehensive search of peer-reviewed publications was performed from core collections of electronic databases such as PubMed, Web of Science, Google Scholar, and Science Direct. Articles written in English-language from inception until December 2022 were selected.

RESULTS

In this review, we review key toxic mechanisms of lead and its pathological effects on the neurological, reproductive, renal, cardiovascular, hematological, and hepatic systems. We focus on plant polyphenols against lead toxicity and involved mechanisms. Finally, we address scientific gaps and challenges associated with translating these promising preclinical discoveries into effective clinical therapies.

CONCLUSION

While preclinical evidence suggests that plant polyphenols exhibit bioprotective effects against lead toxicity, scant and equivocal clinical data highlight a need for clinical trials with those polyphenols.

Serum klotho and its associations with blood and urine cadmium and lead across various stages of glomerular function: data for US adults aged 40-79 years

Exposures to cadmium and lead can cause oxidative stress, leading to tissue damage resulting in kidney and cardiovascular diseases. The antiaging protein klotho, on the other hand, is known to act as an anti-oxidative agent. How klotho homeostasis interacts with exposure to cadmium and lead has not been reported. Thus, this study was carried to investigate associations of serum klotho with blood and urine cadmium and lead in US adults aged 40-79 years across stages of eGFR-based kidney function and albuminuria defined as urinary albumin/creatinine ratio of > 30 mg/g creatinine. As long as the kidney function was normal (eGFR ≥ 90 mL/min/1.73 m²) or near normal (60 ≤ eGFR < 90 mL/min/1.73 m²), there was no evidence of an association between cadmium exposure and klotho concentrations irrespective of the presence/absence of albuminuria. During kidney dysfunction (15 ≤ eGFR < 60 mL/min/1.73 m²), 10% increases in blood cadmium concentrations resulted in decreases in klotho concentrations between 0.27 and 0.84%. In addition, during severe kidney dysfunction (15 ≤ eGFR < 45 mL/min/1.73 m²), a positive association between urine cadmium and serum klotho concentrations was observed. In the absence of albuminuria and when kidney function was normal or near normal, 10% increases in blood lead concentrations were observed to be associated with modest decreases between 0.28% and 0.37% in serum klotho concentrations. Similar results were observed between the concentrations of urine lead and serum klotho during kidney dysfunction.

Effects of environmental and occupational lead toxicity and its association with iron metabolism

BACKGROUND

Discrepancies are present in the findings from clinical trials evaluating a physiological role of iron status in the lead-exposed population.

OBJECTIVE

The purpose of this article was to summarize the current understanding of cellular mechanisms of lead toxicity and present a comprehensive review of existing clinical trials related to associations of lead poisoning and iron status. Although an association of iron metabolism pathways that are affected by lead intoxication has been studied, there are still aspects that remain to be elucidated. The existence of additional Pb uptake pathways besides DMT1 transporter-mediated is postulated to non-specifically regulate lead absorption.

METHODS

Authors performed a systematic search of PubMed, EMBASE® and Web of Science databases to identify studies that reported an association between health risks of non-organic lead that are associated with iron status markers as possible effect modifier.

RESULTS

There were 58 studies that met the pre-defined inclusion criteria for the systematic review. There is a strong body of evidence supporting the hypothesis that alleviated blood lead level can be correlated with a reduced body iron store and increasing the risk of anemia. This association is of a high significance in cases of a young adolescent, weaker in groups of older children and often without a statistical significance in adults.

DISCUSSION

Discrepancies in the observations may result from different specificities of lead absorption pathways in children and adults, as well as the power of the statistical tests in varying population sizes. It may be assumed that the extent of iron deficits coupled together with source, timing, and severity of lead exposure, significantly influence the correlation between these factors. Some of the intervention programs of counteracting lead poisoning by iron supplementation proved to be effective and may be a promising prevention strategy for the exposed population.