ORAL-ADMINISTRATION OF THE OXIDANT-SCAVENGER N-ACETYL-L-CYSTEINE INHIBITS ACUTE EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS

The prevention of acute experimental autoimmune encephalomyelitis (EAE ) by N-acetyl-L-cysteine (NAC), a potent free radical scavenger, is de scribed. Administrated ad libitum to SJL/J mice at a dosage of 0.2-2 m g/ml in drinking water from the day of the encephalitogenic injection, the agent significantly inhibited the induction of acute EAE. The imp rovement in clinical condition was dose-dependent. A complete protecti ve effect required administration of the agent at an early stage. Exam ination of lymphocytes from NAC-treated EAE mice showed that at early stages (days 9 and 15) post encephalitogenic injection the anti-oxidan t enhanced the specific lymphocyte proliferative response to the immun izing antigens. Examination of the mitogenic stimulation of lymphocyte s from naive animals in the presence of NAC in vitro indicated that th e scavenger enhanced the stimulative effect of LPS in a dose-dependent manner. The immunomodulative capacity of the anti-oxidant NAC suggest s that free radicals are involved in the pathogenesis of acute EAE.