Geraniol Protects Against the Protein and Oxidative Stress Induced by Rotenone in an In Vitro Model of Parkinson's Disease.

Dysfunction of autophagy, mitochondrial dynamics and endoplasmic reticulum (ER) stress are currently considered as major contributing factors in the pathogenesis of Parkinson's disease (PD). Accumulation of oxidatively damaged cytoplasmic organelles and unfolded proteins in the lumen of the ER causes ER stress and it is associated with dopaminergic cell death in PD. Rotenone is a pesticide that selectively kills dopaminergic neurons by a variety of mechanism, has been implicated in PD. Geraniol (GE; 3,7-dimethylocta-trans-2,6-dien-1-ol) is an acyclic monoterpene alcohol occurring in the essential oils of several aromatic plants. In this study, we investigated the protective effect of GE on rotenone-induced mitochondrial dysfunction dependent oxidative stress leads to cell death in SK-N-SH cells. In addition, we assessed the involvement of GE on rotenone-induced dysfunction in autophagy machinery via α-synuclein accumulation induced ER stress. We found that pre-treatment of GE enhanced cell viability, ameliorated intracellular redox, preserved mitochondrial membrane potential and improves the level of mitochondrial complex-1 in rotenone treated SK-N-SH cells. Furthermore, GE diminishes autophagy flux by reduced autophagy markers, and decreases ER stress by reducing α-synuclein expression in SK-N-SH cells. Our results demonstrate that GE possess its neuroprotective effect via reduced rotenone-induced oxidative stress by enhanced antioxidant status and maintain mitochondrial function. Furthermore, GE reduced ER stress and improved autophagy flux in the neuroblastomal SK-N-SH cells. The present study could suggest that GE a novel therapeutic avenue for clinical intervention in neurodegenerative diseases especially for PD.