Comparative effects of cadmium, lead, and mercury exposure and the protective role of ginger (Zingiber officinale) tea on hematological and gastrointestinal oxidative stress in Wistar rats

Abstract

Exposure to toxic metals such as cadmium (Cd), lead (Pb), and mercury (Hg) remains a major public health concern due to their persistence and biological toxicity. These metals induce oxidative stress, impair hematological function, and disrupt gastrointestinal integrity. Ginger ( Zingiber officinale ) possesses antioxidant and cytoprotective properties, but its comparative protective effects against Cd, Pb, and Hg-induced toxicity remain insufficiently explored. This study evaluated the effects of Cd, Pb, and Hg on hematological, intestinal, and colonic antioxidant parameters in rats, and assessed the protective potential of ginger tea. Rats were assigned to control, metal-induced (Cd, Pb, or Hg), and respective ginger-treated groups. Blood, intestinal, and colonic samples were collected for hematological analysis; antioxidant enzyme assays including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione-S-transferase (GST); glutathione (GSH) concentration; and malondialdehyde (MDA) levels. Results were statistically compared across groups to determine the extent of toxicity and therapeutic recovery. Cd, Pb, and Hg exposure caused significant reductions in CAT, SOD, GPx, GST, and GSH, accompanied by increased MDA levels in both intestinal and colonic tissues. Hematological disturbances included altered erythrocyte indices, reduced hemoglobin concentration, and disrupted leukocyte differentials. The colon exhibited the greatest susceptibility to oxidative injury. Ginger tea significantly improved antioxidant enzyme activity, restored GSH levels, reduced MDA, and partially normalized hematological alterations. Recovery was the greatest in Hg-exposed groups, followed by Pb, with Cd showing moderate improvement. Cd, Pb, and Hg induce marked hematological and gastrointestinal toxicity primarily through disruption of antioxidant defense systems and hematological balance. Ginger tea provides substantial protective effects, demonstrating antioxidant enhancement, reduced oxidative damage, and partial hematological restoration. These findings support ginger tea as a promising natural strategy for mitigating metal-induced toxicity.