Effect of propolis supplementation on cadmium toxicity associated with renal and hepatic dysfunction in rats

Cadmium (Cd), one of the toxic heavy metals, is of great importance for public health due to its use in many industrial areas. Propolis is a natural product with antioxidant and anti-inflammatory properties collected from plants by honey bees. The aim of this study was to investigate the protective role of propolis against the potential toxic effects of cadmium chloride in blood, liver and kidney tissues. For this purpose, rats were divided into four groups. Control group, propolis (150 mg/kg b.w.) treated group, cadmium chloride (1.76 mg/kg b.w. 1/50 LD50) treated group and cadmium chloride plus propolis (1.76 mg/kg b.w. and 150 mg/kg b.w. respectively) treated group. The substances were given to rats by gavage for 28 days. After 28 days of treatment, a statistically significant change was observed in serum biochemical parameters such as ALT, AST, BUN, LDH, urea, uric acid and creatinine, hematological parameters such as erythrocyte, hemoglobin and hematocrit, and IL-1 beta and IL-6 cytokine levels of cadmium chloride treated rats compared to the control group. In addition, significant changes were observed in mRNA expression levels of Casp-3, p53 and Tnf-alpha genes, HSP70, HSP90 and GRP78 protein levels and histopathological/immunohistochemical examinations. Improvement in biochemical and hematologic parameters, cytokines, mRNA expression, heat shock proteins and immunohistochemistry changes were observed in cadmium plus propolis treated group compared to cadmium treated group.