Lutein protects dopaminergic neurons against MPTP-induced apoptotic death and motor dysfunction by ameliorating mitochondrial disruption and oxidative stress

Abstract

Objective: Mitochondrial dysfunction and oxidative stress-mediated apoptosis plays an important role in various neurodegenerative diseases including Huntington’s disease, Parkinson’s disease (PD) and Alzheimer’s disease (AD). 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), the most widely used neurotoxin mimics the symptoms of PD by inhibiting mitochondrial complex I that stimulates excessive intracellular reactive oxygen species (ROS) and finally leads to mitochondrial-dependent apoptosis. Lutein, a carotenoid of xanthophyll family, is found abundantly in leafy green vegetables such as spinach, kale and in egg yolk, animal fat and human eye retinal macula. Increasing evidence indicates that lutein has offers benefits against neuronal damages during diabetic retinopathy, ischemia and AD by virtue of its mitochondrial protective, antioxidant and anti-apoptotic properties.

Methods: Male C57BL/6 mice (23-26 g) were randomized and grouped in to Control, MPTP, and Lutein treated groups.

Results: Lutein significantly reversed the loss of nigral dopaminergic neurons by increasing the striatal dopamine level in mice. Moreover, lutein-ameliorated MPTP induced mitochondrial dysfunction, oxidative stress and motor abnormalities. In addition, lutein repressed the MPTP-induced neuronal damage/apoptosis by inhibiting the activation of pro-apoptotic markers (Bax, caspases-3, 8 and 9) and enhancing anti-apoptotic marker (Bcl-2) expressions.

Discussion: Our current results revealed that lutein possessed protection on dopaminergic neurons by enhancing antioxidant defense and diminishing mitochondrial dysfunction and apoptotic death, suggesting the potential benefits of lutein for PD treatment.

Keywords:

• Parkinson's disease
• Mitochondrial dysfunction
• Oxidative stress
• Apoptosis and lutein

Acknowledgements

The research project was funded by the Indian Council of Medical Research, New Delhi, is gratefully acknowledged.

Disclaimer statements

Contributors J.N. carried out animal study. T.M. guided the work. J.T. helped for statistical analysis. M.M.E. helped for manuscript preparation.

Funding None.

Conflicts of interest The authors declare that they have no conflict of interest that might have influenced the views expressed in the manuscript.

Ethics approval We got approval from the animal ethical committee.