Résumé
The aim of the work is to study the effect of Commiphora mukul [CM] extract on pituitary thyroid axis in rats. Twenty four adult male albino rats were used in this study divided into four groups equally [control, CM group [orally administered in a dose of 0.2 g/Kg b.w/d of CM extract], hypothyroid group [hypothyroidism was induced by adding thiouracil to the drinking water at concentration of 0.03%] and hypothyroid plus CM group].The result of the present work showed that oral administration of CM extract either in normal or hypothyroid rats produced significant increase of triiodothyronine [T[3]], thyroxin [T4], T3/T4 ratio and the activity of peroxidase and proteases enzymes, it also produced significant decreased in thyroid stimulating hormone [TSH], cholesterol and hepatic lipid peroxidation [LPO] when these results are compared to those of control, or hypothyroid group, with the exception of hepatic LPO which is insignificantly changed after oral administration of CM in hypothyroid rats, when this result is compared to hypothyroid group. We can conclude that thyroid stimulating effect of CM is different from that TSH and is probably not mediated through the pituitary, it acts directly on thyroid through increase the activity of peroxidase and proteases enzymes also enhance T3 more than T4 through decrease in lipid peroxidation in the liver