Protective effects of curcumin and resveratrol on neurodegeneration and cognitive dysfunction in a streptozotocin-induced alzheimer rat model

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that is characterized by memory loss, cognitive decline, and behavioral disturbances. Given the limited efficacy of current treatments, there is an urgent need for new neuroprotective strategies. In this study, the therapeutic potential of curcumin and resveratrol was evaluated in a rat AD model induced by intracerebroventricular (ICV) administration of streptozotocin (STZ) (3 mg/kg). Subsequent to model induction, rats were administered curcumin, resveratrol, or a combination of both. The behavioral analyses, which included the Morris water maze, open field, and passive avoidance tests, revealed that both compounds significantly improved learning and memory performance. The histological and immunohistochemical findings demonstrated a decrease in caspase-3 and GFAP immunoreactivity, suggesting reduced neuronal apoptosis and astrocyte activation. The behavioral analyses, which included the Morris water maze, open field, and passive avoidance tests, revealed that both compounds significantly improved learning and memory performance. The histological and immunohistochemical findings demonstrated a decrease in caspase-3 and GFAP immunoreactivity, suggesting reduced neuronal apoptosis and astrocyte activation. Biochemical results showed an increase in total antioxidant status (TAS) and superoxide dismutase (SOD) activity, along with a decrease in total oxidative status (TOS) and TNF-α levels. Stereological evaluation also confirmed partial restoration of hippocampal volume. While curcumin and resveratrol exhibited potent neuroprotective effects when used separately, no synergistic interaction was observed when used in combination. These findings suggest that curcumin and resveratrol may serve as promising therapeutic agents for reducing oxidative stress, neuroinflammation, and neuronal degeneration associated with Alzheimer's disease.