Protective effects of lycopene against amyloid β-induced neurotoxicity in cultured rat cortical neurons

The neurotoxicity of amyloid beta (A beta) has been implicated as a critical cause in the pathogenesis of Alzheimer's disease (AD). Among antioxidant phytochemicals derived from fruit and vegetables, lycopene has recently received considerable attention for its potent protective properties already demonstrated in several models of oxidative damage. The present study aims to investigate whether lycopene could provide protective effects against A beta-induced neurotoxicity in primary cultured rat cortical neurons. The cultured cortical neurons were pretreated with different dose of lycopene for 4 h, followed by the challenge with 25 mu M A beta(25-35) for 24 h. The results showed that pretreatment with lycopene efficiently attenuated A beta(25-35)-induced neurotoxicity, as evidenced by the improved cell viability and the decreased apoptotic rate. In addition, lycopene inhibited the reactive oxygen species generation and mitochondrial membrane potential depolarization caused by A beta(25-35). Lycopene also restored the levels of proapoptotic Bax, antiapoptotic Bcl-2, and inhibited caspase-3 activation. These beneficial effects may contribute to the protection against A beta-induced neurotoxicity. Together, our results suggest that the natural antioxidant lycopene has potential for neuroprotection and therefore, may be a promising candidate for AD treatment. (C) 2011 Elsevier Ireland Ltd. All rights reserved.