Niacin produces an inconsistent treatment response in the EAE model of multiple sclerosis.

Niacin was found in the lysolecithin model of multiple sclerosis (MS) to promote the phagocytic clearance of debris and enhance remyelination. Lysolecithin lesions have prominent microglia/macrophages but lack lymphocytes that populate plaques of MS or its experimental autoimmune encephalomyelitis (EAE) model. Thus, the current study assessed the efficacy of niacin in EAE. We found that niacin inconsistently affects EAE clinical score, and largely does not ameliorate neuropathology. In culture, niacin enhances phagocytosis by macrophages, but does not reduce T cell proliferation. We suggest that studies of niacin for potential remyelination in MS should include a therapeutic that targets adaptive immunity.