Curcumin Improves Memory Impairment and Restores Irregular Neuronal Distribution In ‎the Hippocampal CA1 Region After Global Cerebral Ischemia in Male Rats

Purpose: Global Cerebral Ischemia (GCI) causes neuronal damage that leads to neurological and cognitive impairments. Curcumin has anti-inflammatory, antioxidant and neuroprotective properties which makes it a potential candidate for improving GCI-induced impairments. The aim of this study was to investigate the effects of curcumin on the neurological and memory deficits as well as spatial neuronal distribution in the CA1 region after GCI in rats. Methods: Fifty-six Sprague-Dawley male rats were randomly assigned into four groups of sham (n=14), control (n=14), curcumin 50 mg/kg (n=14), and curcumin 100­ mg/kg (n=14). Each group was divided into two subgroups of short-term (7 ­days) and long-term (28 ­days) treatment periods. The Neurological Severity Score (NSS), passive avoidance task and the traction test were performed at postoperative days of 0, 1, 2, 3, 7, 14, 21, and 28.  The Novel Object Recognition Test (NORT) and Voronoi tessellation were carried out on days 7 and 28 after GCI. Results: Curcumin­ 100­ mg/kg significantly decreased NSS on postoperative days of 7 and 28 in comparison with the control (p<0.001) and curcumin 50­ mg/kg groups (P<0.05-P<0.001), and increased step-through latency times on postoperative days of 3-28 and 14-28 compared to the control (P<0.05-P<0.001) and curcumin 50 mg/kg groups (P<0.01-P<0.001), respectively. Moreover, it increased novelty preference index during the NORT in the 28-day treatment subgroup after GCI. Curcumin­ (100­ mg/kg) was able to maintain the neuronal aggregation in the CA1 region after GCI at a level near to what is generally observed in normal rats. Conclusion: Curcumin could improve memory and neurological deficits and restored irregular neuronal distribution in the CA1 region after GCI in a time-dependent manner, and its higher dose was more effective than its lower dose. Curcumin may have beneficial effects on reducing brain complications after ischemia.