Neuroprotective effects of α-lipoic acid on long-term experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an animal model commonly used in research on the acute phase of multiple sclerosis (MS), but studies on the pathology and pathogenesis of EAE with a long disease course are seldom conducted. Besides its antioxidant properties, the comprehensive mechanisms through which α-lipoic acid (LA) affects EAE remain obscure. We here conducted the study to explore the possible mechanisms.

In this study, the following methods were used for investigating the effects of LA on long-term EAE: hematoxylin-eosin staining (HE) and electron microscopic examinations of pathological changes; Western blotting of β-amyloid precursor protein (β-APP) and myelin basic protein (MBP); Enzyme-linked immunosorbent assay (ELISA) of tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), superoxide dismutase (SOD), malondialdehyde (MDA) as well as flow cytometry of CD4+CD25+FoxP3+ regulatory T cells (Tregs).

The results showed: (1) diverse pathological features of long-term relapsing-remitting EAE; (2) relatively increased MBP and reduced β-APP expression in LA recipients 180 days after onset; (3) down-regulated TNF-α and up-regulated TGF-β levels in LA recipients 7 days after onset; (4) lower MDA and higher SOD levels in LA recipients 180 days after onset; (5) increased Treg levels in LA recipients 7 days after onset.

Aside from oxidative stress, LA possessed anti-inflammatory and immunomodulatory effects on EAE. LA might be a promising candidate for MS treatment.