Background and aims: Concanavalin A (Con A) activates T lymphocytes and induces CD4(+) T cell-mediated hepatic injury in mice. Pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), and interleukin-6 (IL-6), are critical mediators in this experimental model. Activation of adenosine A(2A) receptors reduces the production of various pro-inflammatory cytokines and suppresses T cell activation. A selective adenosine A2A receptor agonist (ATL-146e) has been shown to be a potent inhibitor of inflammation by increasing intracellular cyclic AMP (cAMP) in leukocytes. The aim of the present study was to determine whether ATL-146e could ameliorate Con A-induced hepatic injury, reduction of pro-inflammatory cytokine production. Methods: Balb/c mice were injected with 25 mg/kg Con A with or without a single injection of ATL-146e (0.5-50 mu g/kg), 5 min prior to Con A administration. Liver enzymes, histology, and serum levels of tumor necrosis factor-alpha, interferon-gamma, and interleukin-6 were examined. We also assessed the effects of ATL-146e on pro-inflammatory cytokine production with CD4(+) T cell. Results: Pretreatment with ATL-146e significantly reduced serum levels of liver enzymes (P < 0.001). The serum pro-inflammatory cytokines were all increased after Con A administration and reduced to near normal levels by ATL-146e. ATL-146e also inhibited CD4(+) T cell pro-inflammatory cytokine production. Conclusion: A selective adenosine A(2A) receptor agonist, ATL-146e, can prevent concanavalin A-induced hepatic injury that is presumably mediated by its anti-inflammatory properties. (c) 2006 Elsevier Inc. All rights reserved.