The Protective Effect of Selenium versus Ascorbic Acid on Potassium Dichromate-induced Thyroid Toxicity in Adult Male Albino Rats.

BACKGROUND

Potassium dichromate (PD) is considered a common inorganic chemical reagent, and it is considered one of the hexavalent chromium Cr (VI) compounds; these compounds have genotoxic, carcinogenic, and immunotoxic effects. It induces thyroid gland toxicity via oxidative stress. Selenium (Se) and ascorbic acid (Vitamin C) are known for their antioxidant role, and therefore, they are essential for humans and animals. Limited studies investigated the role of selenium versus ascorbic acid in protecting the thyroid gland from PD toxicity and so this study was designed.

AIM: This study aims to assess the protective impact of selenium versus ascorbic acid against PD-induced thyroid toxicity in adult male albino rats.

MATERIALS AND

METHODS

In this study, 42 adult male albino rats were randomized into six equivalent groups. Each animal received intraperitoneal injection of a treatment once daily for five successive days: The control group received distilled water; the selenium group received sodium selenite; the ascorbic acid group received Vitamin C; the PD group received potassium dichromate; the PD and selenium group received sodium selenite 1 h before PD; and the PD and Vitamin C group received Vitamin C 1 h before PD. By the end of the experiment, scarification of all animals was done, and their thyroid glands were extracted and processed for light microscopic examination after staining with hematoxylin and eosin, Masson's trichrome, periodic acid-Schiff, and proliferating cell nuclear antigen (PCNA) immunostaining.

RESULTS

Thyroid gland sections of the PD group revealed loss of the thyroid general architecture. The follicles showed disrupted basal lamina, epithelial hypertrophy, hyperplasia, and sloughing. Colloid vacuolation was also seen. There was a significant decrease in the follicular diameter and area percentage of colloids. There was also an increase in the follicular cell height, area percentage of collagen, and number of PCNA immune-positive nuclei compared to the control group. Sections of the PD and selenium and PD and ascorbic acid groups showed a significant histological improvement compared to the PD group with no significant difference between both the groups.

CONCLUSION

Both selenium and ascorbic acid had a similar partial protective effect on the thyroid gland against PD-induced toxicity in male adult albino rats.