Abstract
The present study investigates the neuroprotective effects of the sea urchin Paracentrotus lividus gonadal extract on rotenone-induced neurotoxicity in a Parkinson's disease (PD) rat model. Parkinson's disease, characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN), is exacerbated by oxidative stress and neuroinflammation. The study involved fifty Wistar rats divided into five groups: control, dimethyl sulfoxide (DMSO) control, Paracentrotus lividus gonadal extract-treated, rotenone-treated, and combined rotenone with Paracentrotus lividus gonadal extract-treated. Behavioral assessments included the rotarod and open field tests, while biochemical analyses measured oxidative stress markers (malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH)), antioxidants (superoxide dismutase (SOD), catalase (CAT)), pro-inflammatory cytokines (interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α)), and neurotransmitters (dopamine (DA), levodopa (L-Dopa)). Histological and immunohistochemical analyses evaluated the neuronal integrity and tyrosine hydroxylase (TH) and alpha-synuclein expression. The results showed that Paracentrotus lividus gonadal extract significantly mitigated rotenone-induced motor deficits and improved locomotor activity. Biochemically, the extract reduced oxidative stress and inflammation markers while enhancing antioxidant levels. Histologically, it restored neuronal integrity and reduced alpha-synuclein accumulation. Molecularly, it increased tyrosine hydroxylase and dopa decarboxylase gene expression, essential for dopamine synthesis. These findings suggest that Paracentrotus lividus gonadal extract exerts neuroprotective effects by modulating oxidative stress, neuroinflammation, and dopaminergic neuron integrity, highlighting its potential as a therapeutic agent for Parkinson's disease.