Rotenone a widely used pesticide that inhibits mitochondrial complex I has been 
used to investigate the pathobiology of PD both in vitro and in vivo. Studies 
have shown that the neurotoxicity of rotenone may be related to its ability to 
generate reactive oxygen species (ROS), leading to neuronal apoptosis. The 
current study was carried out to investigate the neuroprotective effects of 
hesperidin, a citrus fruit flavanol, against rotenone-induced apoptosis in human 
neuroblastoma SK-N-SH cells. We assessed cell death, mitochondrial membrane 
potential, ROS generation, ATP levels, thiobarbituric acid reactive substances, 
reduced glutathione (GSH) levels, and the activity of catalase, superoxide 
dismutase (SOD) and glutathione peroxidase (GPx) using well established assays. 
Apoptosis was determined in normal, rotenone, and hesperidin treated cells, by 
measuring the protein expression of cytochrome c (cyt c), caspases 3 and 9, Bax, 
and Bcl-2 using the standard western blotting technique. The apoptosis in 
rotenone-induced SK-N-SH cells was accompanied by the loss of mitochondrial 
membrane potential, increased ROS generation, the depletion of GSH, enhanced 
activities of enzymatic antioxidants, upregulation of Bax, cyt c, and caspases 3 
and 9, and downregulation of Bcl-2, which were attenuated in the presence of 
hesperidin. Our data suggests that hesperidin exerts its neuroprotective effect 
against rotenone due to its antioxidant, maintenance of mitochondrial function, 
and antiapoptotic properties in a neuroblastoma cell line.