The dynamic face of cadmium-induced Carcinogenesis: Mechanisms, emerging trends, and future directions

Metformin alleviates cadmium-induced reproductive toxicity by enhancing mitochondrial biosynthesis and epigenetic modifications in female mice

Cadmium, a pervasive environmental pollutant, exerts detrimental effects on various tissues and cells, particularly targeting the reproductive system, thereby posing significant risks to both animal food safety and human health. Despite its widespread impact, research on substances capable of mitigating cadmium-induced reproductive toxicity remains scarce, especially concerning female reproductive health. Metformin, a widely used oral antihyperglycemic drug, has demonstrated a range of beneficial effects, including anti-aging and antioxidant properties. This study aims to investigate the potential and underlying mechanisms of metformin in alleviating cadmium-induced reproductive toxicity in females. Over a period of 35 consecutive days, mice were exposed to cadmium-contaminated water (32 mg/l) and orally administered 10 mg metformin dissolved in 0.2 ml normal saline. Our findings reveal that metformin effectively mitigates cadmium-induced disruptions in the estrous cycle, follicular development, and oocyte meiotic maturation. Specifically, metformin enhances ATP production in oocytes by boosting mitochondrial mass and biosynthesis, thereby counteracting cadmium-induced oxidative stress and spindle morphology defects during meiosis. Additionally, metformin restores the DNA repair capacity of oocytes, alleviating cadmium-induced DNA damage. This restorative effect is partially mediated by metformin's ability to improve key epigenetic modifications, such as histone acetylation, histone methylation, and DNA methylation in oocytes. These results underscore metformin's potential as a protective or therapeutic agent against cadmium reproductive toxicity, primarily by maintaining cellular homeostasis to bolster oocyte resilience against cadmium toxicity and preserving normal epigenetic modifications to ensure oocyte quality.

Association of blood cadmium levels with all-cause and cause-specific mortality among adults with non-alcoholic fatty liver disease: a prospective cohort study

Background

Cadmium (Cd) accumulates in the body over time, damaging organs such as the liver, kidneys, and brain. Some researchers have suggested that elevated blood Cd levels may contribute to the onset and progression of nonalcoholic fatty liver disease (NAFLD). However, only a few studies have explored the relationship between Cd exposure and long-term health outcomes in patients with NAFLD. This study aimed to evaluate the predictive value of blood cadmium levels for mortality risk in patients with NAFLD.

Methods

This study analyzed data from 13,450 patients with NAFLD in the National Health and Nutrition Examination Survey (NHANES) database, covering the years 1999 to 2018. Patients were categorized into three groups based on their blood Cd levels. The relationship between blood cadmium concentrations and all-cause, cardiovascular, and cancer mortality in NAFLD patients was assessed using Cox proportional hazards regression while accounting for potential confounders. Results were visualized using Kaplan-Meier and restricted cubic spline (RCS) curves. Stratified analyses were performed for validation of the robustness of the results.

Results

After adjusting for all covariates, blood Cd levels were positively associated with all-cause, cardiovascular, and cancer mortality in patients with NAFLD, showing a significant linear dose-response relationship. Specifically, for each unit increase in Log-transformed blood cadmium concentration, the risk of all-cause mortality increased by 191% (HR = 2.91, 95% CI: 2.39-3.53); cardiovascular mortality risk increased by 160% (HR = 2.6, 95% CI: 1.80-3.76); and cancer mortality risk increased by 279% (HR = 3.79, 95% CI: 2.54-5.65). Stratified analysis confirmed the robustness of these findings.

Conclusion

Our study suggests that high Blood Cd levels adversely affect the prognosis of patients with NAFLD. Individuals with NAFLD should be aware of Cd exposure and take preventive measures. Moreover, stricter environmental protection policies may be necessary to reduce Cd exposure.

Serum Levels of Heavy Metals in Patients with Prostate Cancer: A Systematic Review and Meta-analysis

Prostate cancer (PC) is a common malignancy among men globally. Although genetic, hormonal, and environmental factors contribute to its development, the role of heavy metals remains unclear. This study evaluated serum levels of arsenic, cadmium, lead, mercury, and nickel in PC patients compared to healthy controls. An extensive search of PubMed, Embase, Scopus, and Google Scholar identified relevant studies published up to December 2023. Studies reporting the mean and standard deviation of serum heavy metal levels in PC patients and controls were included. Random-effects models were used to estimate mean differences (MD) or standardized mean differences (SMD) with 95% confidence intervals (CIs). Heterogeneity was evaluated based on I2 index, and publication bias was examined using funnel plots. Seven studies involving 691 participants were included. No significant difference was found in serum levels of arsenic between PC patients and controls (MD: 0.04, 95% CI: [-0.15, 0.23]; p = 0.68). Cadmium (SMD: 0.93, 95% CI: [-0.06, 1.93]; p = 0.07) and lead (SMD: 0.65, 95% CI: [-0.22, 1.52]; p = 0.14) were higher in PC patients but not statistically significant. Mercury levels also showed no substantial difference (MD: 0.22, 95% CI: [-0.27, 0.70]; p = 0.38). However, serum nickel levels were significantly higher in PC patients (SMD: 0.62, 95% CI: [0.07, 1.16]; p = 0.03). The study demonstrated a substantial increase in serum concentration of nickel in PC patients compared to controls, indicating a potential role of nickel in PC pathogenesis. Although other heavy metals showed elevated levels in PC patients, these differences were not statistically significant. Further research is needed to explore nickel as a potential biomarker for early PC detection.