Antioxidant Profiling of Lycopene Extract in Rat PC-12 (Pheochromocytoma) Cells Exposed to Neurotoxic Shock

Lycopene, the most potent antioxidant among various common carotenoids, protects against the threat of neurodegeneration and works as a neuroprotective agent by preventing mitochondrial dysfunctions, microglia activation and focal cerebral ischemia in rats. To study the antioxidant properties of lycopene, the levels of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and glutathione-S-transferase (GST) and non-enzymatic parameters such as glutathione (GSH) and lipid peroxidation were analyzed in PC-12 cells treated with 6-hydroxydopamine (6-OHDA) and lycopene. Cell viability was also determined using MTT assay in these samples. Since 6-OHDA is a neurotoxic agent, it caused a decrease in levels of antioxidant enzymes, SOD, CAT, GST, GSH and cell viability. Lipid peroxidation levels were increased in PC-12 cells after treatment with 6-OHDA. But on further treatment of cells exposed to 6-OHDA with lycopene, the levels of these enzymes and the cell counts were increased to nearly 80% as compared to the control and lipid peroxidation levels were decreased to 75% as compared to the control. Altered activities of these antioxidant enzymes upon treatment with 6-OHDA were restored to almost normal level upon treatment of cells with lycopene. This may be due to the antioxidant property of lycopene which regulated the neuronal cells defense system against neurotoxic shock.