Abdullateef Isiaka Alagbonsi,Luqman Aribidesi OlayakiAbdulrahim Halimat AminMariam Titilayo SuleimanIsrael BojuwadeNoah Adavize OmeizaSheu Oluwadare Sulaiman2025-05-072025-05-072020-03Keywords: Iodine; Ketoconazole; Melatonin; Thyroid function; Toxicityhttps://dx.doi.org/10.4314/rjmhs.v3i1.2https://uilspace.unilorin.edu.ng/handle/123456789/16314The antithyroid effect of ketoconazole has been reported. The secretion and action of melatonin in the thyroid gland are also known. However, the possible effect of melatonin on ketoconazole-induced antithyroid effect is unknown. Objective We sought to investigate the modulatory effect of ketoconazole and/or melatonin on thyroid function in female rats. Methods Groups 1-4 of female rats respectively underwent 14-day treatment with normal saline, 25 mg/kg ketoconazole, 4 mg/kg melatonin and 10 mg/kg melatonin. Groups 5 and 6 both received 14-day treatment with ketoconazole and were respectively treated with 4 mg/kg melatonin and 10 mg/kg melatonin simultaneously. Groups 7 and 8 respectively underwent 14-day pretreatment with 4 mg/kg melatonin and 10 mg/kg melatonin, followed by 14-day administration of ketoconazole to both groups. Groups 9 and 10 were both treated with ketoconazole for 14 days, followed by respective 14-day administration of 4 mg/kg melatonin and 10 mg/kg melatonin. Results TSH, T3, T4, and iodine concentrations were increased by separate administration of ketoconazole and either dose of melatonin when compared to control. However, pre-treatment or post-treatment of ketoconazole- treated rats with melatonin abolished the ketoconazole-induced increase in TSH, T3, T4, and iodine while co-administration of ketoconazole with melatonin caused no improvement in the ketoconazole-induced increase in TSH, T3, and T4 except iodine concentration. Conclusion Ketoconazole increased thyroid function, which was ameliorated by pre- or post-treatment with melatonin, possibly via modulation of the iodination process.enArticle