Cadmium Chloride-Induced Hepatotoxicity: Molecular Mechanisms, Oxidative Stress, and Histopathological Alterations—A Comprehensive Review

Abstract

Cadmium chloride (CdCl) is a highly dangerous heavy metal commonly used in electroplating, pigment production, battery manufacturing, plastic stabilization, and other laboratory settings. Due to the speed of industrial growth and human activities, cadmium levels in air, water, and soil have gone up dramatically, This way the compound is a leading reason for environmental and occupational contamination of health. Essential trace elements are those the body relies on but with cadmium, the body does not. In fact, its biological half-life is up to forty years, making the chemical progressively accumulate in tissues. Although the kidney has long been known as the prime organ involved in chronic lead poisoning, cadmium absorption actually causes rapid damage to the liver due to this organ's primary role in metabolism and detoxification of foreign substances (xenobiotics). CdCl liver accumulation initiates many pathological responses including overproduction of reactive oxygen species (ROS), exhaustion of the cell's antioxidant systems, mitochondrial malfunctions, release of inflammatory cytokines, cell death, and fibrosis. At a larger level of tissues and functions, all these changes cause disturbances in liver structure and function leading to hepatocellular injury. Oxidative stress and disruption of calcium homeostasis are just two mechanisms of cadmium toxicity besides other effects like antioxidant enzyme inhibition, DNA and membrane (lipid) damage, and activation of several intracellular signaling pathways such as NF-B, MAPK, and Nrf2. From a histological standpoint, changes include liver cell (hepatocyte) alterations, widened blood sinuses, cells of the immune system coming into the tissue, blood vessels in a state of congestion, spots of necrosis (cell death), and fibrosis. From a clinical point of view, liver damage caused by CdCl is seen as an increase in the levels of some biomarkers, viz. alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and bilirubin, as indicators of disease state changes and alteration of enzyme activities for antioxidant defense (e.g. glutathione peroxidase).The article reviews the present state of knowledge on cadmium environmental exposure sources, toxicokinetic pattern of CdCl, mechanisms responsible for cadmium-induced liver damage, and the corresponding histopathological and biochemical manifestations. Comprehending the molecular events involved is a crucial step toward the designing of strategies aimed at preventing cadmium-induced liver injuries identification of biological indicators of exposure, and formulation of new ways of treatment that will lessen liver damage caused by cadmium exposure.