Potential role of lactoferrin in early diagnostics and treatment of Parkinson disease

Abstract

Incidence of Parkinson disease progressively grows with increasing age and percentage of elderly people in the global population. Clear understanding of the causes of dopaminergic neurons death in Substantia nigra and Parkinson disease pathogenesis are currently absent, not speaking of an efficient therapy. However, an early diagnosis of dopaminergic neurons degeneration and prescription of dopamine replacement therapy significantly slow down the rate of symptoms progression. An increased concentration of iron in Substantia nigra of Parkinson disease patients has been shown in several studies. In this review we summarized the data concerning a potential significance of lactoferrin, the iron-binding protein of exocrine secretions and neutrophils, for early diagnosis and treatment of Parkinson disease. Salivary and lacrimal lactoferrin levels in Parkinson disease patients were higher than those observed in the control group. Plasma levels of lactoferrin inversely correlated with Parkinson disease severity even after treatment with Levodopa, a dopamine agonist, and with monoaminooxidase inhibitors. Lactoferrin levels in cerebrospinal fluid of Parkinson disease patients negatively correlated with the tumor necrosis factor-alpha concentration. Lactoferrin treatment of rodents with several experimental models of Parkinson disease (induced by rotenone, MPTP) protected neurons and mitigated the symptoms of neurodegeneration. Some contradictions about the positive effects of lactoferrin as a remedy in Parkinson disease animal models and possible participation of lactoferrin in accumulation of iron in neurons are discussed.