Curcumin differentially regulates the expression of superoxide dismutase in cerebral cortex and cerebellum of L-thyroxine (T₄)-induced hyperthyroid rat brain.

The present investigation was aimed to elucidate the effect of curcumin on lipid peroxidation (LPx) and superoxide dismutase (SOD) in L-thyroxine (T4)-induced oxidative stress in cerebral cortex and cerebellum of rat brain. Elevated level of LPx in cerebral cortex declined to control level on supplementation of curcumin to T4-treated rats. On the other hand, unaltered LPx level in T4-treated rats showed a significantly decreased level of LPx on supplementation of curcumin. The increased activity of SOD and translated products of SOD1 and SOD2 in cerebral cortex of T4-treated rats was ameliorated on supplementation of curcumin. The decreased activity of SOD and protein expression of SOD1 in cerebellum of T4-treated rats were ameliorated on administration of curcumin. On the other hand, SOD2 expression was not influenced either by T4-treated or by curcumin supplementation to T4-treated rats. Results of the present investigation reveal that the regulation of expression of SOD by curcumin in different regions (cerebral cortex and cerebellum) of rat brain is different under hyperthyroidism.