Restorative effects of curcumin on sleep-deprivation induced memory impairments and structural changes of the hippocampus in a rat model
The present study examined the consequences of rapid eye-movement sleep-deprivation (REM-SD) with or without curcumin treatment. The outcome measures comprised quantitative features in the three-dimensional reconstruction (3DR) CA1 and dentate gyrus in experimental and control animals using stereological procedures.
Male rats were arbitrarily assigned to nine groups based on the intervention and treatment administered including: 1-cage control + distilled water, 2-cage control + curcumin (100 mg/kg/day), 3-cage control + olive oil, 4-REM-SD + distilled water, 5-REM-SD + curcumin, 6-REM-SD + olive oil, 7-grid-floor control + distilled water, 8-grid-floor control + curcumin, and 9-grid-floor control + olive oil. Animals in the latter three groups were placed on wire-mesh grids in the sleep-deprivation box. REM-SD was induced by an apparatus comprising a water tank and multiple platforms. After a period of 21 days, rats were submitted to the novel object-recognition task. Later, their brains were excised and evaluated using stereological methods.
Our results indicated a respective 29% and 31% reduction in the total volume of CA1, and dentate gyrus in REM-SD + distilled water group as compared to the grid-floor control + distilled water group (p < 0.05). Other than the above, the overall number of the pyramidal cells of CA1 and granular cells of dentate gyrus in the sleep-deprived group were found to be reduced by 48% and 25%, respectively. The REM-SD + distilled water group also exhibited impaired object recognition memory and deformed three-dimensional reconstructions of these regions. The volume, cell number, reconstruction, object recognition time, and body weight were however recovered in the REM-SD + curcumin compared to the REM-SD + distilled water group. This suggests the potential neuro-restorative effects of curcumin in our model.