Phytosterols ameliorate clinical manifestations and inflammation in experimental autoimmune encephalomyelitis

Using experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis (MS), the objective of this study was to examine the effect of phytosterol (PS) administration on inflammation-based EAE development. Female SJL mice were orally administered PS prior to disease induction and maintained throughout the experiment. EAE was induced with antigenic peptide (PLP(131-155)). Mice were clinically scored for disease and euthanized for biochemical and histological analysis of inflammation. PS delayed onset of EAE development by 2 days and decreased disease severity by 55%. Brain histological analysis revealed an 82% decrease in central nervous system (CNS) inflammatory infiltration and a 48% decrease in demyelination in PS-treated mice versus control. Immunohistochemistry (IHC) showed a 35% reduction in macrophages entering brains of PS-treated mice. Anti-inflammatory interleukin (IL)-10 was up-regulated by 10%, while pro-inflammatory CCL2 was inhibited by 50% with PS treatment. Additionally, PS slightly decreased other pro-inflammatory factors, such as tumor necrosis factor (TNF)-alpha, IL-6, and interferon (IFN)-gamma. PS protects against development of EAE by reducing infiltration and inflammatory activity of immune cells into CNS of treated mice, thereby decreasing demyelination associated with EAE. These results provide evidence to support PS as a preventative agent that helps to protect against the development of inflammation-driven disease, such as MS.