ABSTRACT
The present investigation was an attempt to study the effect of low molecular weight sulfated chitosan (LMWSC) on in vitro rotenone model of Parkinson's disease (PD) by evaluating cell viability, oxidative stress, mitochondrial membrane potential, DNA fragmentation, and apoptosis. Incubation of SH-SY5Y cells with 100 nm rotenone resulted in neuronal cell death, redox imbalanced mitochondrial dysfunction, DNA fragmentation, condensation, and apoptotic cellular morphology. Rotenone exposure enhanced the expression of preapoptotic (cytochrome C (cyto c), caspase-3, -8, -9, and Bax) and down-regulated the expression of anti-apoptotic (Bcl-2) markers. Reduction of the intracellular reactive oxygen species (ROS) levels ensued due to pretreatment of LMWSC along with consequent normalization of antioxidant enzymes, mitigation of rotenone induced mitochondrial dysfunction and apoptosis. Our current findings suggested that LMWSC exhibit the pronounced neuroprotective effects, which could be due to its antioxidant, mitochondrial protection, and anti-apoptotic properties. We thus conclude that LMWSC could be developed as a novel therapeutic molecule for the benefit of reducing the consequences of PD. However, further extensive preclinical and clinical studies are warranted.
Subject(s)
Antiparkinson Agents/pharmacology , Chitosan/pharmacology , Neuroprotective Agents/pharmacology , Parkinsonian Disorders/drug therapy , Apoptosis/drug effects , Apoptosis/physiology , Cell Line, Tumor , Cell Survival/drug effects , Cell Survival/physiology , Chitosan/analogs & derivatives , DNA Fragmentation/drug effects , Dose-Response Relationship, Drug , Humans , Membrane Potential, Mitochondrial/drug effects , Membrane Potential, Mitochondrial/physiology , Neurons/drug effects , Neurons/metabolism , Neurons/pathology , Oxidative Stress/drug effects , Oxidative Stress/physiology , Parkinsonian Disorders/metabolism , Parkinsonian Disorders/pathology , Reactive Oxygen Species/metabolism , RotenoneABSTRACT
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.
