Improvement of experimental allergic encephalomyelitis (EAE) by thymoquinone; an oxidative stress inhibitor.

UNLABELLED: Experimental Allergic Encephalomyelitis (EAE) is an autoimmune demyelinating disease of the central nervous system that is widely accepted as an animal model for the human multiple sclerosis. Oxidative stress appears to play a role in the onset and progression of EAE. We reasoned that decreasing oxidative stress might ameliorate symptoms and signs of EAE. Thymoquinone is reported to inhibit oxidative stress. One way of decreasing oxidative stress is to induce glutathione (GSH). We tested the impact of Thymoquinone (1 mg/kg, injected at tail vein) in our EAE model. We induced (EAE) in female Lewis rats using myelin basic protein emulsified with complete Freund's adjuvant. 24 animals were placed into three groups: A) Rats with EAE B) EAE rats with concomitant five day injection of Thymoquinone days 1-5, C) EAE rats with five doses of Thymoquinone injected at day 12-17. Twenty-eight days later, animals were sacrificed; spinal cord tissues collected for glutathione (GSH). RESULTS: 63% of animals in group "A" developed hind limb weakness and/or paralysis while 37% developed mild tail weakness, perivascular inflammation and low spinal cord GSH level. 25% of animals in group "B" exhibited mild tail and hind limb weakness and 75% animals had no symptoms, no perivascular inflammation and high spinal cord GSH level. 63% of animals of group "C" showed improving symptoms following Thymoquinone injections, no perivascular inflammation and higher GSH level while 37% of animals showed no symptoms prior and post Thymoquinone injections. Clinical symptoms correlated well with perivascular inflammation and GSH level. Animals received Thymoquinone at day 12-17 had higher GSH level, no perivascular inflammation and no symptoms compared with other groups. CONCLUSION: Thymoquinone inhibited oxidative stress which leads into improvement in our EAE animals. Thymoquinone may have a role in treatment of Multiple Sclerosis.

Detection of ICAM-1 in experimentally induced colitis of ICAM-1-deficient and wild-type mice: an immunohistochemical study.

Adhesion molecules (e.g. ICAM-1, CD 54) are known to be upregulated on activated vascular endothelial cells during inflammatory reactions. To study the role of ICAM-1 in intestinal inflammation in vivo, we induced acute experimental colitis in wild-type (C57BL/6) mice and ICAM-1-deficient mice, by feeding the animals with 3% dextran sodium sulphate (DSS) in drinking water for 7 days. In the control strain the immunohistochemical staining showed a very pronounced endothelial upregulation of ICAM-1 after the DSS treatment observed in areas of inflammatory infiltrate, especially in venules or arterioles of the propria and submucosa, and partly in the mesocolon. DSS-fed ICAM-1-deficient mice showed no endothelial enhancement and only faint staining of venules or capillaries approaching that encountered in the control ICAM-1-deficient animals. Our data indicate that ICAM-1 may play a crucial role in the development of acute intestinal inflammation, consistent with our finding that ICAM-1 deficiency can obviate severe forms of experimentally induced colitis in mice.

Intercellular adhesion molecule-1 (ICAM-1) deficiency protects mice against severe forms of experimentally induced colitis.

ICAM-1 (CD54), the ligand for LFA-1 and Mac-1, is up-regulated during inflammatory reaction on the activated vascular endothelium. To determine its role in intestinal inflammation, we induced acute experimental colitis in mice with a deleted ICAM-1 gene, by feeding them with 3% dextran sodium sulphate (DSS) in drinking water for 7 days. Chronic colitis was elicited by DSS similarly, followed by 2 weeks with water. In the acute phase of inflammation, ICAM-1-deficient mice exhibited a significantly lower mortality rate (5%) than control C57Bl/6J mice (35%). Control animals, but not the ICAM-1-deficient mice, exhibited diarrhoea and rectal bleeding. Histological examination of large-bowel samples evaluated the intensity of inflammatory changes, and type and extent of mucosal lesions. In the acute phase, 33.3% of samples from ICAM-1-deficient mice exhibited mucosal defects (flat and fissural ulcers), predominantly mild to moderate inflammatory infiltrate within the lamina propria mucosae and lower grades of mucosal lesions. Much stronger inflammatory changes were present in control animals, flat ulcers (sometimes multiple) and fissural ulcers being observed in 62.5% of samples. Mucosal inflammatory infiltrate was moderate to severe, typically with higher grades of mucosal lesions. In chronic colitis, smaller inflammatory changes were found in the large bowel. The two mouse strains differed, the chronic colitis being accompanied by an increased serum level of anti-epithelial IgA autoantibodies in C57Bl/6 control mice but not in ICAM-1-deficient mice. These findings provide direct evidence of the participation of ICAM-1 molecule in the development of experimentally induced intestinal inflammation.