Lycopene reduces deltamethrin effects induced thyroid toxicity and DNA damage in albino rats

Deltamethrin is a synthetic pyrethroid widely used as the insecticide of choice in most countries because of its high activity against a broad spectrum of insect pests. This experimental study aimed to evaluate the histopathological and ultrastructural changes in the thyroid caused by deltamethrin, also to further evaluate the potential genotoxic activity of deltamethrin and the possible protective effect of lycopene. The study was performed on 32 mature male albino rats which were randomly divided into four groups as follows: 1- control group; 2- lycopene group; 3- deltamethrin group; and 4- deltamethrin + lycopene group. The animals were sacrificed and tissue samples taken from the thyroid were processed for both light microscopy and transmission electron microscopy. Light microscopic examination of the deltamethrin group revealed hyperemia, vacuolization in the lining epithelium, and detached and desquamated follicular cells in the follicular lumen. Ultrastructural examination showed vacuolated cytoplasm, numerous lysosomes, cellular debris, dilated rough endoplasmic reticulum and pyknotic nuclei. Lycopene supplementation reduced the thyroid cellular changes. Electron microscopic study supports the histopathological study, where the cytoplasm had nearly normal rough endoplasmic reticulum except for the presence of some vacuoles. Moreover, lycopene reduced the DNA damage of thyroid cells as observed from the significant decrease in the comet assay (tail length and damaged DNA%). All these results suggest the efficacy of lycopene in amelioration of thyroid gland structures as well as DNA damage which may result from its antioxidant properties.