Protective Role of Thyme Oil (Thymus vulgaris) Against Cadmium Chloride-Induced Renal Damage in Common Carp (Cyprinus carpio)

The present study aimed to evaluate the role of thyme oil in reducing the histopathological effects in the kidneys of common carp (Cyprinus carpio) exposed to two different concentrations of cadmium chloride (16.86 and 56.2 mg/L). The experiment included 6 groups, each containing 16 fish: G1, G2, G3, G4, G5, G6. The results showed the presence of histopathological changes in the kidneys of fish. They were more severe in the two groups treated with cadmium chloride only. They decreased in the two groups treated with cadmium chloride and thyme oil together. The study also showed that the longer exposure period increased the severity of the changes in the two groups treated with cadmium chloride only, especially after 30 days from the beginning of the experiment. Histological changes included dilatation of renal tubules, expansion of Bowman's capsule space, necrosis and degeneration of endothelial cells and renal tubules, increased mast cells and melanomacrophage aggregates. In contrast, histological changes were less severe in the two groups treated with cadmium chloride and thyme oil. This indicates the protective role of thyme oil in reducing the severity of histopathological changes.