GEMSP exerts a myelin-protecting role in the rat optic nerve

Objectives: Chronic experimental autoimmune encephalomyelitis (EAE) was induced in rats to evaluate the potential protective effect of GEMSP, a mixture made up of fatty acids (FA), vitamins, and amino acids or their derivatives, linked to Poly-L-Lysine, on the myelin sheath of the optic nerve. Methods: To evaluate the effects of GEMSP on the optic nerve, animals were divided into three experimental groups: (1) EAE rats treated with GEMSP; (2) EAE rats treated with 0.9% NaCl; and (3) control, non-EAE rats. Using electron microscopy, we investigated the possibility that this new drug candidate has a myelin-protective role. Results: A marginally significant reduction in the thickness of the myelin around optic nerve medium-size axons (diameter between 0.8-1.3 mu m) was found in EAE rats. Treatment of EAE rats with GEMSP ameliorated myelin damage. Significantly increased myelin thickness was found when animals in groups 2 and 3 were compared. However, the number of myelinated axons studied was not altered in groups 1 or 2 when compared to controls. Discussion: Our results suggest that in a model of demyelination, GEMSP protects and enhances the formation of the myelin sheath of the optic nerve and therefore could be a potential drug candidate to reduce optic nerve pathogenesis in multiple sclerosis (MS).