General Physiology and Biophysics Vol.42, No.1, p 49–57, 2023

The study investigated the effect of exogenous melatonin and (or) curcumin treatment on the cerebral cortex of adult rats. In this context, malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH), superoxide dismutase (SOD), nuclear factor E2-related factor 2 (Nrf2) and SIRT2 protein expression were examined. A total of 30 Wistar albino rats involved in the study were randomly divided into five groups. Over 30 days, the control groups received phosphate-buffered saline or dimethyl sulfoxide injections, and the treatment groups received melatonin, curcumin, or a combination of melatonin and curcumin injections. In the cerebral cortex homogenates, the MDA, GSH, and sum of NO were respectively determined by the thiobarbituric acid, modified Ellman and Griess test methods. The SOD and Nrf2 levels were examined using the ELISA method and SIRT2 protein expression using the Western blot technique.

The study found that both melatonin and curcumin treatments significantly reduced lipid peroxidation and SIRT2 protein expression levels (p < 0.05) and increased the Nrf2 level in the cytoplasm (p < 0.05). The study revealed that curcumin and melatonin treatments reduced MDA and SIRT2 protein expression level and increased intracellular Nrf2, GSH, and SOD in the cortex tissue. We also found that the combined melatonin and curcumin treatment produced no synergistic effect.