Amelioration of the chronic relapsing experimental allergic encephalomyelitis (CR-EAE) using thymoquinone
Axonal damage, demyelination and inflammation of the central nervous system are the major pathological features of multiple sclerosis (MS). MS is thought to be due to an abnormal T cell mediated immune response. Oxidative stress plays an important role in the advancement of MS. The reduced glutathione (GSH) has very important role in the management of oxidative stress. In our experiment we used Experimental autoimmune encephalomyelitis (EAE) animal model that mimic human MS and tested the effect of Thymoquinone (TQ) a constituent of oil of Nigella Sativa also known as black seed. Thirty female mice strain C57BL/6J between 6 to 12 weeks of age were placed into 3 groups of 10 and MOG was used subcutaneously (s.c) to induce EAE. Group A, the control group. Group B, received MOG (s.c) and TQ intraperiotoneally (i.p) from day 1 till day 50. Group C, received MOG (s.c) and TQ (i.p) was given on the appearance of first sign and symptoms of Chronic relapsing EAE (CR-EAE). All Mice were examined daily for behavioral deficits and all euthanized and sacrificed on day 50. In this study we found mice belonging to group C (EAE with TQ treatment after the appearance of chronic symptoms) were observed to have the highest mean clinical scores in both the acute and chronic phases of EAE with symptom reduction following the TQ injections. Group B (which received daily TQ injections) had decreased symptoms compared to Group A and C. Glutathione level dropped significantly in the control group (p < 0.05) and increased (p > 0.05) in groups B and C mice who received TQ injections. We also noted that EAE clinical signs correlated well with the extent of perivascular lymphocyte infiltrate compared with normal histology following TQ injections. Our results indicate that TQ, due to its anti-oxidant effects is almost 80% preventive and 50% curative in CR-EAE. These results could assist further studies on the mechanism of the action of TQ in CR-EAE and on the possibility of treating the chronic- relapsing phase of human multiple sclerosis. It seems within the realm of possibility that TQ may be as, if not more, therapeutically efficacious as interferon β and glatiramer acetate.
multiple sclerosis, thymoquinone, antioxidant, chronic relapsing experimental allergic encephalom, black seed
Master of Science (M.Sc.)