Introduction: Chlorpyrifos is a broad-spectrum insecticide with widespread usage in agricultural fields despite its toxic effects on human health. Avocado is a highly valuable fruit proven to have curative and preventive role in numerous diseases.
Aim: To evaluate the protective role of avocado pulp extract on chlorpyrifos-induced injury on the thyroid gland in rats.
Materials and Methods: Forty adult male albino rats were divided into four equal groups; control group, avocado-treated group (300 mg/kg), chlorpyrifos-treated group (5.4 mg/kg), and both avocado- and chlorpyrifos-treated group. Doses were given orally, daily for 4 consecutive weeks. Specimens of the thyroid gland were processed for histological and immunohistochemical examinations. A morphometric study and statistical analysis of the findings were performed for different groups.
Results: Compared to the control group, the specimens of the chlorpyrifos-treated rats showed degenerated follicles with exfoliated follicular cells in the lumen. Increased amount of collagen fibers and decreased PAS-reaction were observed. Immunohistochemistry showed a significant increase in caspase-3 immunoexpression. The mean height of the thyroid follicular epithelial cells was significantly decreased with significant decrease in area of colloid. In contrast, minimal changes appeared in the group treated concomitantly with both avocado and chlorpyrifos.
Conclusion: Avocado pulp extract exerted an excellent role in protecting the thyroid gland from chlorpyrifos injurious-effects in rats.