Amelioration of adjuvant induced arthritis by apocynin.

The premise of the study was to investigate the antiarthritic potential of apocynin (APO) in Balb/c mice (in vivo). The experiment showed a dose-dependent decrease in oedema and showed a suppression of proinflammatory cytokines such as TNF-alpha and IL-1beta and mediators such as prostaglandin E(2) (PGE(2)) and LTB(4). At oral doses of 0.5, 1.0, 2.0 and 4.0 mg/kg once daily during the course of the experiment, APO induced an inhibition of T cell mediated immune response causing suppression of CD4+ and CD8+ T cells and of intracellular interferon-gamma (IFN-gamma) by flow cytometry in arthritic mice. In parallel there was a dose-dependent inhibition in vascular permeability causing an inhibition in the migration of leucocytes and exudate volume at the site of the inflammatory reaction. These observations validate the immunoregulatory potential of apocynin. (c) 2009 John Wiley & Sons, Ltd.