Protective Effects of Curcumin and Resveratrol on Neurodegeneration and Cognitive Dysfunction in a Streptozotocin-induced Alzheimer Rat Model

Alzheimer's disease (AD) is a degenerative neurological disorder characterized by progressive impairment of memory, cognition, and behavior. Since current treatment approaches have been unable to significantly slow the progression of the disease, there is an increasing need for new neuroprotective strategies. This study aims to investigate the protective effects of curcumin and resveratrol on neurotoxicity and the resulting cognitive impairments. A total of 60 male Wistar albino rats were included in the study and divided into six groups: Alzheimer's disease (ALZ) group, ALZ + curcumin (ALZ + CUR) group, ALZ + resveratrol (ALZ + RES) group, ALZ + curcumin + resveratrol (ALZ + CUR + RES) group, and SHAM group. Behavioral tests demonstrated that curcumin and resveratrol significantly improved neurobehavioral outcomes. Histological analyses revealed that curcumin and resveratrol reduced the density of cells stained with Caspase 3 (+) and GFAP (+), thereby alleviating neuronal cell death and astrocyte activation. Stereological analyses demonstrated that curcumin and resveratrol improved the STZ-induced hippocampal volume reduction. Serum levels of TAS and TOS measured in serum samples indicated that oxidative stress induced by STZ was reduced by curcumin and resveratrol. While these two compounds exhibited neuroprotective effects when administered alone, no such effect was observed when administered together, suggesting that combination therapy did not produce the expected synergistic effect. In conclusion, curcumin and resveratrol, when administered alone, reduced oxidative stress and neuroinflammation caused by STZ, prevented neuronal apoptosis, and improved learning and memory functions, demonstrating significant neuroprotective effects in ALZ. These findings suggest that curcumin and resveratrol may serve as effective therapeutic agents in the treatment of Alzheimer's disease.