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

OBJECTIVE: 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.

MATERIALS AND METHODS: 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).

RESULTS: 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.

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