Oral Administration of Cadmium Chloride Induces Oxidative Stress, DNA Damage and Histopathological Changes in Rat Intestine: A Dose-Dependent Study.

Cadmium (Cd) is a heavy metal that is a persistent environmental contaminant. Cd has gained global attention due to its widespread use in industries and represents an occupational hazard. Humans are exposed to Cd via the oral route throughout their lifetime, which can adversely affect their health. The present study was done to delineate the mechanism of acute toxicity of cadmium chloride (CdCl₂) on rat intestine. Adult male Wistar rats were given a single oral dose of CdCl₂ at 30, 60, 90, and 120 mg/kg body weight. The administration of CdCl₂ impaired the enzymatic and non-enzymatic antioxidant defense systems, which lowered the total antioxidant capacity of intestinal cells. The oxidation of lipids, proteins, and thiol groups was significantly increased. The activities of enzymes of the brush border membrane and glucose metabolism were also altered. DNA strand scission and DNA-protein cross-linking were enhanced in CdCl₂-treated rats. Histopathologic images supported the biochemical findings and showed detrimental changes in the intestine of CdCl₂-treated rats. All effects were seen in a CdCl₂ dose-dependent manner. The results of this study strongly suggest that the toxic effects of CdCl₂ in rat intestine are due to the induction of oxidative stress that lowers the antioxidant defense system, leading to tissue damage.