Curcumin treatment reduces motor impairments and protects against rotenone-induced neurodegeneration in a rat model of Parkinson disease.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by degeneration of dopaminergic neurons, leading to motor impairments (bradykinesia, rigidity, tremor) and non-motor symptoms (cognitive decline, psychiatric disturbances). This study investigated the neuroprotective effects of curcumin in a rotenone-induced PD rat model. Male albino rats received daily intraperitoneal injections of rotenone (2 mg/kg) and/or curcumin (200 mg/kg) for 9 weeks. Behavioral assessments revealed that curcumin treatment significantly improved motor function, reducing catalepsy duration and increasing rearing frequency in cylinder tests. Histological analysis showed curcumin preserved neuronal density in both hippocampal and pedunculopontine nucleus (PPN) regions. Electrophysiological recordings showed that that curcumin modulated hippocampal responses to PPN high-frequency stimulation (100 Hz). These results suggest curcumin exerts multimodal neuroprotection by preserving neuronal integrity and stabilizing hippocampal-PPN circuitry. While our findings highlight curcumin's therapeutic potential, further studies quantifying synaptic markers and direct LTP measurements are needed to fully elucidate its effects on synaptic plasticity.