The possible anti-apoptotic and antioxidant effects of acetyl l-carnitine as an add-on therapy on a relapsing-remitting model of experimental autoimmune encephalomyelitis in rats

Multiple sclerosis (MS) is a progressive inflammatory autoimmune demyelinating disease of the brain and spinal cord. Glucocorticoids (GCs) are the standard treatment of MS, however they have several drawbacks like oxidative stress and apoptosis. This study was designed to evaluate some possible antioxidant, anti-apoptotic and immune modulatory effects of Acetyl-l-carnitine (ALCAR) when used either alone or as an add-on therapy with dexamethasone for treatment of a relapsing-remitting (RR) experimental autoimmune encephalomyelitis (EAE) as a model of MS. This experiment was performed on 50 female Sprague Dawley rats divided into; normal control group, untreated EAE group, EAE group treated by dexamethasone, EAE group treated by ALCAR, and EAE group treated by both dexamethasone and ALCAR. The clinical score of the motor deficit of EAE was recorded daily. At the end of experiment, rats were sacrificed and the brain and spinal cord were processed for assessment of reduced glutathione (GSH), malondialdehyde (MDA) and caspase-3 activity. Histopathological changes and immunohistochemical expression of Bcl-2 and CD4+ T cell were carried out. Combination of both dexamethasone and ALCAR provided marked antioxidant and anti-apoptotic effects represented by significant decrease in MDA, caspase-3 and significant increase in GSH, Bcl-2 expression, and it also exhibited marked immunosuppressive effect represented by significant decrease in CD4+ T cells expression with significant improvement in clinical outcome when compared to untreated EAE group or to dexamethasone treated group. These findings pave the way for using ALCAR as an adjuvant therapy during long-term use of dexamethasone in MS.