Folic acid ameliorates L-thyroxin induced hepatotoxicity and oxidative stress in albino rats.

Document Type : Original Article

Authors

1 Department of Zoology, Faculty of Science, Menoufia University, Egypt

2 Department of Zoology, Faculty of Science, Tanta University, Egypt

Abstract

Thyroid hormones have been known to regulate the energy metabolism of most tissues including liver. Alterations in their normal levels cause some biochemical and clinical abnormalities such as hypothyroidism and hyperthyroidism. The present study evaluated the effect of thyroid hormone, L-thyroxin on liver of albino rats. Additionally the ameliorating role of folic acid supplementation was investigated. Fifty male albino rats were randomly divided into five groups (group I, control; group II, folic acid; group III, L-thyroxin sodium administration (100 μg/kg / body weight); group IV, L-thyroxin and folic acid group and V, recovery group). The results showed that there were a significant increase in ALT, AST, MDA and nitric oxide in L-thyroxin treated rats as compared to control group. On the other hand, a significant decrease in glutathione (GSH) in L-thyroxin treated rats as compared to control group. Histological results showed that liver sections of L-thyroxin group showed histopathological lesions such as leucocytic infiltrations, congestion of central and portal veins and cytoplasmic vacuolation of hepatocytes with the presence of pyknotic nuclei, in addition to fatty infiltration. Immunohistochemical results revealed that strong positive expression of PCNA, P53, and Bcl-2 were detected in the liver section in L-thyroxin treated rats and recovered rats as compared to control and folic acid groups. However; mild to moderate positive expressions of PCNA, P53, and Bcl-2 were observed in rats treated with L-thyroxin and folic acid in liver section. This reflects oxidative stress associated with hyperthyroid state.

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