Clove Essential Oil Enhances Antioxidant Defenses and Reduces DNA Damage in a Cellular Model of Parkinson's Disease

Oxidative stress is a major contributor to the pathogenesis of Parkinson's disease, promoting neuronal degeneration through the production of excessive reactive oxygen species. In this context, natural products such as essential oils are attracting increasing attention for their potential to protect neurons. Clove essential oil (CEO), which is extracted from the flower buds of the plant Syzygium aromaticum, is renowned for its antioxidant activity. This study aimed to investigate the chemical composition, antioxidant properties, and protective effects of CEO on SH-SY5Y cells, which are used as a cellular model of Parkinson's disease. The CEO was obtained by hydrodistillation (yield: 15%) and is primarily composed of eugenol (84.49%) and acetyl-eugenol (10.05%). Its antioxidant activity was confirmed via DPPH radical scavenging (IC₅₀ = 0.081 ± 0.001 mg/mL) and iron chelation (110.32 ± 0.67 mg EDTA equivalent/g essential oil (EO)). qRT-PCR, Western blot, and slot blot techniques demonstrated that CEO pretreatment at concentrations of 2.5, 5, and 10 μg/mL significantly reduced 6-OHDA-induced oxidative DNA damage and restored the gene and protein expression of key antioxidant enzymes (GPx1, GPx4, SOD1, and CAT). These results highlight the powerful antioxidant and neuroprotective properties of CEO, supporting its potential as a therapeutic agent for neurodegenerative disorders related to oxidative stress, such as Parkinson's disease.