Cadmium exposure is associated with overexpression of the metallothionein gene and heightened urinary deoxy-guanosine and protein carbonylation status in an exposed population of West Bengal, India
摘要
Cadmium (Cd), being a heavy metal, causes myriad clinical problems if exposed to the environment through food or drinking water or through inhalation. The river Churni of West Bengal is highly contaminated with heavy metals, particularly Cd, due to the disposal of waste materials from paint, sugar, and textile industries. People residing in the catchment area of the river are using the river water for drinking, cooking, and household work, and, therefore, are exposed to high levels of Cd throughout the years.
ObjectiveEvaluation of biomarkers in chronic Cd-induced health hazards.
MethodA total of 105 study participants were recruited to evaluate chronic Cd-exposure-induced biomarkers. Among them, 50 were from the Cd-exposed population, and 55 were from the unexposed control. Cadmium concentration was measured by Graphite Furnace AAS in drinking and cooking water samples, and the biological samples (blood, urine) collected from every participant.
ResultThe extent of oxidative DNA damage, protein carbonylation, plasma nitrate, and malondialdehyde (MDA) concentration was measured in people and found to be significantly higher in the Cd-exposed population in comparison to the unexposed control. Expression of the metallothionein (MT) gene and protein has also been studied in both populations, with significantly higher MT gene expression observed in the Cd-exposed population. Evaluation of cell death using the comet assay and acridine orange/propidium iodide staining revealed significantly higher comet tail moment and apoptosis in isolated lymphocytes from exposed participants.
SignificanceThus, it can be concluded that Cd exposure is associated with oxidative damage and health risk. Cadmium-induced oxidative damage and MT gene expression in the exposed population can serve as a biomarker.
Impact statementThis cross-sectional study demonstrates that Cd-induced oxidative damage and MT gene expression can serve as biomarkers in a chronically exposed population. In the future, protein carbonylation, oxidative DNA damage, and MT gene expression may serve as biomarkers of Cd exposure-induced health hazards for diagnostic purposes.