Shikonin ameliorates experimental autoimmune encephalomyelitis (EAE) via immunomodulatory, anti‐apoptotic and antioxidative activity

Objectives Multiple sclerosis is a common autoimmune inflammatory disease of the central nervous system. There are several underlying mechanisms for the pathogenesis of the disease, including inflammation, oligodendrocyte apoptosis and oxidative stress. Methods The mechanism of action of shikonin was investigated in the C57BL/6 experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis. Key findings The results revealed that EAE induction significantly increased the extent of demyelination in the corpus callosum tissues of the animals, while treatment of the mice with shikonin significantly decreased the extent of demyelination. Real‐time polymerase chain reaction‐based analysis of the brain samples from the EAE mice revealed significant enhancement in the expression levels of tumour necrosis factor‐α ( TNF‐α ), interferon‐γ ( IFN‐γ ) and Bax genes as well as a reduction in the expression levels of transforming growth factor‐ß ( TGF‐β ) and Bcl2 . But, shikonin treatment significantly reduced the expression levels of TNF‐α , IFN‐γ and Bax . On the other hand, the expression levels of TGF‐β and Bcl2 as well as the activity of glutathione peroxidase‐1 (GPX‐1) enzyme were significantly increased following the shikonin treatment. Conclusions This study emphasized the immune‐modulatory and antioxidative effects of shikonin, which may have an important healing effect on the severity of EAE.