Roles of Lycopene During Neurite Development of Primary Hippocampal Neurons

Abstract Objectives Neurite outgrowth and branching is critical during neuronal development. Failure to achieve proper neurite complexity is highly associated with developmental disorders. We have previously shown that oxidative stress contributes to alteration of neurite morphology. Therefore, nutrients capable of regulating neuronal redox balance may help maintain normal neurite development. We have recently found that lycopene, a nutritional antioxidant, protects mitochondria by preventing generation of mitochondrial superoxide. In this study, we hypothesize that treatment with lycopene improves development of primary hippocampal neurons under physiological conditions. Methods Primary hippocampal neurons were grown in neurobasal media with or without 0.1 μM lycopene for 1, 3, 5, 7, and 14 days, and imaged using a Zeiss Axio Vert.A1 microscope. Neurons were classified into 4 different categories: stage I, circular and non-polar neurons; stage II, presence of minor neurites without polarity; stage III, neurons with polarity; and stage IV, neurons with dendritic branches. We also performed Sholl analysis to quantify intersections of neurites evaluating neurite complexity. Results Primary hippocampal neurons grown in media containing lycopene showed advanced neuronal development. In particular, lycopene treatment significantly advanced polarity and dendritic arborization in immature neurons. In addition, neurons grown in lycopene showed improved neurite branching at their maturity. Conclusions This study shows that lycopene supports neurite growth and branching during development. Therefore, we suggest novel role of lycopene during physiological development of the brain, or potential therapeutic effect against developmental disorders. Funding Sources RGC Program (University of Alabama) Crenshaw Research Fund (University of Alabama).