Possible ameliorative effect of curcumin and levothyroxine on potassium dichromate‑induced hypothyroidism in male albino rats

Abstract

Potassium dichromate is a toxic heavy metal that contains chromium and causes hypothyroidism. The study aimed to evaluate the effectiveness of curcumin and levothyroxine in preventing potassium dichromate-induced hypothyroidism in adult male albino rats. Fifty six adult male albino rats were splited into eight groups (n=7/each). Group 1 (G1) was used as an untreated control group. G2 was administered corn oil (0.4 ml/rat). G3 was given curcumin (100 mg/kg/ b.wt). G4 was administered levothyroxine (20 μg/kg/ b.wt). From G2 to G4, rats were orally administered for 4 weeks. G5, G6, G7, and G8 were injected with potassium dichromate (2 mg/kg/b.wt) intraperitoneally for two weeks. Then, G6, G7, and G8 were received curcumin, levothyroxine, and curcumin/levothyroxine as in G3, and G4, respectively. The thyroid stimulating hormones (TSH), triiodothyronine (T3), thyroxine (T4), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and myeloperoxidase (MPO) were evaluated in serum. Reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were measured in the thyroid tissue. Thyroid tissues were taken for histological examination. The results showed that in G5, a significant increase in TSH, and a decrease in T3 and T4 levels were reported when compared to G1. TNF-α, IL-6 and MPO have also significantly increased in G5. Furthermore, there was a significant decrease in GSH content, SOD, and CAT activities, and a significant increase in MDA level in G5 thyroid tissues. The histological examinations of thyroid tissues confirmed these results. The combination of curcumin and levothyroxine (G8) achieved the highest recovery from potassium dichromate (G5) toxic effects.