Zeolite and Neurodegenerative Diseases

Abstract

Neurodegenerative diseases (NDs), characterized by progressive degeneration and death of neurons, are strongly related to aging, and the number of people with NDs will continue to rise. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common NDs, and the current treatments offer no cure. A growing body of research shows that AD and especially PD are intricately related to intestinal health and the gut microbiome and that both diseases can spread retrogradely from the gut to the brain. Zeolites are a large family of minerals built by [SiO₄]^4- and [AlO₄]^5- tetrahedrons joined by shared oxygen atoms and forming a three-dimensional microporous structure holding water molecules and ions. The most widespread and used zeolite is clinoptilolite, and additionally, mechanically activated clinoptilolites offer further improved beneficial effects. The current review describes and discusses the numerous positive effects of clinoptilolite and its forms on gut health and the gut microbiome, as well as their detoxifying, antioxidative, immunostimulatory, and anti-inflammatory effects, relevant to the treatment of NDs and especially AD and PD. The direct effects of clinoptilolite and its activated forms on AD pathology in vitro and in vivo are also reviewed, as well as the use of zeolites as biosensors and delivery systems related to PD.

Keywords: Alzheimer’s disease; Parkinson’s disease; anti-inflammatory; antioxidative effect; clinoptilolite; detoxifying; zeolite.

Figure 1

Structure of zeolites. (A) Primary and secondary building units of zeolite. The primary building units represent tetrahedral structures with mostly Si or Al in the center of the tetrahedron and O atoms at the corners (left), which are shown to be linking the tetrahedrons in the secondary units (right). (B) Secondary building units further linked by O atoms and forming a complex three-dimensional lattice underlying the microporous structure of zeolite holding cavities filled with water molecules and ions (by Derbe et al. [52]). (C) Clinoptilolites from the region of Kardzhali, Rhodope mountain, South Bulgaria (collection of the Museum “Earth and People”, Sofia, Bulgaria).

Figure 2

Overview on the various effects of zeolite in relation to neurodegenerative diseases and especially AD and PD. Green arrows denote positive effects and red arrows-negative. ND—neurodegenerative diseases, DAO—diamine oxidase, ZO-1—Zonula occludens-1.