Supplementation of curcumin and vitamin E enhances oxidative stress,but restores hepatic histoarchitecture in hypothyroid rats

AimsIn the present study, the effects of vitamin E and curcumin on hepatic dysfunction, mitochondrial oxygen consumption as well as hyperlipidemia in hypothyroid rats are reported.Main methodsAdult male rats were rendered hypothyroid by administration of 0.05% 6-n-propyl-2-thiouracil (PTU) in their drinking water, while vitamin E (200 mg/kg body weight) and curcumin (30 mg/kg body weight) were supplemented orally for 30 days.Key findingsHypothyroidism-induced elevation in serum aspartate aminotransferase activity was found to decline in vitamin E and curcumin treated rats. Nevertheless, distorted histoarchitecture revealed in hypothyroid rat liver was alleviated to normal by vitamin E and curcumin treatment. Regulation of hypothyroidism induced decrease in complexes I and II mediated mitochondrial respiration by vitamin E and curcumin was found to be different. Administration of curcumin to hypothyroid rats alleviates the decreased state 4 respiration and increased respiratory control ratio (RCR) level in complex I mediated mitochondrial oxygen consumption, whereas complex II mediated respiration was not influenced by exogenous antioxidants. Although, increase in serum concentration of total cholesterol was not modified by exogenous antioxidants, increased level of non-high-density lipoprotein cholesterol (non-HDL-C) in serum of hypothyroid rats was further enhanced by vitamin E and curcumin. Moreover, a significant elevation in mitochondrial lipid peroxidation and protein carbonylation was noticed in hypothyroid groups treated with vitamin E and curcumin.SignificanceThe present study suggests that supplementation of curcumin and vitamin E enhances oxidative stress parameters and hyperlipidemia; nevertheless, it protects hypothyroid-induced altered rectal temperature, serum transaminase activity and hepatic histoarchitecture.