The neuroprotective effect of Clove essential oil against 6-OHDA-induced cell death in SH- SY5Y and a rat model of Parkinson's disease

Abstract

Abstract Parkinson's disease (PD) is the second most prevalent neurological disorder. Natural therapies are becoming more popular for preventing disease onset. Clove essential oil (CEO), a potent antioxidant derived from Syzygium aromaticumbuds, was tested in vitro (SH-SY5Y) and in vivo (PD rat model) for its ability to protect against 6-OHDA-induced cell death. Twenty-four hours of SH-SY5Y cells' exposure to 6-OHDA (100 µM) drastically decreased cell viability. At doses lesser than 20 µg/ml, CEO and its main component eugenol (EG) had no cytotoxic effect on SH-SY5Y. CEO and EG at doses of 2.5-20 µg/ml provided significant neuroprotection against 6-OHDA-induced cell death. A PD rat model was generated by injecting 6-OHDA (21µg/animal) unilaterally into the striatum. An assessment of motor performance can predict neuronal cell loss in the substancia nigra compacta (SNc). Compared to 6-OHDA-lesioned, CEO-treated (10mg/Kg) rats' locomotor performance (actimetry and cylinder tests) improved significantly one and two weeks after 6-OHDA-lesion. Tyrosine hydroxylase (TH) cell count showed a significant decrease in cell death in ipsilateral SNc in both CEO-treated and 6-OHDA-lesioned rats when compared to contralateral. In contrast to the 6-OHDA-lesioned group, the ipsilateral SNc of the CEO-treated group showed a significant high TH cell number. In the present study, the neuroprotective effect of CEO was demonstrated both in vitro and in vivoagainst 6-OHDA cytotoxicity. Therefore, CEO could be used as a food supplement for PD prevention.