Vanillin attenuates CdCl2-induced cytotoxicity in isolated human erythrocytes

Abstract

Cadmium is a toxic heavy metal with no physiological role in the human body. Cadmium has high mobility due to its widespread industrial use, with no safe and effective therapeutic management. Cadmium toxicity manifests by increasing oxidative stress in target cells. We have explored the potential role of vanillin, a plant phenolic aldehyde and antioxidant, in mitigating cadmium chloride (CdCl₂) induced hemotoxicity using isolated human erythrocytes. CdCl₂ was added to erythrocytes, in the absence and presence of vanillin. Incubation of erythrocytes with CdCl₂ alone inhibited methemoglobin reductase and enhanced methemoglobin level. Heme degradation and release of free iron (Fe²⁺), along with protein and membrane lipid oxidation, were also increased. A CdCl₂-induced enhancement in reactive oxygen and nitrogen species was also seen, lowering the overall antioxidant power of cells. However, pre-incubation of erythrocytes with vanillin resulted in significant decreased generation of reactive species and prevented heme degradation and heme oxidation. Vanillin augmented the erythrocyte antioxidant capacity and reinstated the activities of major antioxidant, plasma membrane-bound and glucose metabolism enzymes. Scanning electron microscopy showed that CdCl₂ treatment led to the formation of echinocytes which was prevented by vanillin. In all cases, no harmful effects of vanillin alone were seen. Thus, vanillin alleviates the toxicity of cadmium and can be potentially employed as a chemoprotectant against the damaging effects of this heavy metal.

Keywords: Antioxidant; Cadmium chloride; Erythrocytes; Oxidative stress; Vanillin.