Abstract
Today it is well known about mechanisms of cell communication, how the cells that mediate immune response and tissue injury accumulate in tissues but the aetiology of rheumatoid arthritis (RA) is still unknown. This study was to evaluate immunomodulatory effects of crude Entamoeba histolytica (HM1 IMS strain) antigen in complete freund’s adjuvant female wistar rats by studying the alterations in humoral and cell mediated immune responses and also the inflammatory effects by evaluating the changes in body weight, paw thickness, biochemical, serological, interleukin-6 (IL-6), IL-10 and tumor necrosis factor-α (TNF-α) and histopathology activities. Animals were randomly divided into six groups (n=6). CFA was induced in arthritic, drug and AA+CFA group whereas, 0.5ml amoebic antigen was induced subplantal in AA group while 0.5ml dose of amoebic antigen was given orally to AA+CFA group for 7-28th days. Indomethacin was used as a standard drug. Effects of amoebic antigen were associated with increased paw thickness and decreased body weight when compared to healthy control showed a significant difference. Oral administration of amoebic antigen has showed increased severe symptoms of arthritis in AA+CFA on comparison to healthy control rats. Significant increase in serum level of IL-6 and α TNF were found in AA group followed by AA+CFA group whereas, decrease in concentration of IL-10 was appear in AA+CFA group on comparison to arthritic and healthy control group (P<0.05). Histopathology of AA group showed severe signs of necrotic and degenerative changes on comparison to healthy control group. Thus the results demonstrated that E. histolytica alone or in combination with CFA increased bone damage, with alterations in antioxidant level in liver and kidney tissue homogenates as well as showed immunomodulatory arthritogenic properties which may contribute and raise joint inflammation
Keywords: Amoebic antigen, animal model, IL-6, IL-10, immunomodulation, inflammation, rheumatoid arthritis, TNF-α.