NO-naproxen modulates inflammation, nociception and downregulates T cell response in rat Freund's adjuvant arthritis

Br J Pharmacol. 2000 Jul;130(6):1399-405. doi: 10.1038/sj.bjp.0703449.


1. Anti-inflammatory non steroidal drugs releasing NO (NO-NSAIDs) are a new class of anti-inflammatory drugs to which has been added an NO-releasing moiety. These compounds have been shown to retain the anti-inflammatory, analgesic and antipyretic activity of the parent compound but to be devoid of gastrointestinal (GI) toxicity. 2. Freund's adjuvant (FA) arthritis was induced in rats by a single intraplantar injection into the right hindpaw of 100 microl of mycobacterium butirricum (6 mg ml(-1)). The effect of equimolar doses of naproxen (1, 3 and 10 mg kg(-1)) and NO-naproxen (1.5, 4.5 and 16 mg kg(-1)) was evaluated using two dosage regimen protocols: (i) preventive, starting oral administration of the drugs at the time of induction of arthritis and for the following 21 days (day 1 - 21); (ii) therapeutic, starting oral administration of the drugs 7 days after adjuvant injection and for the following 14 days (day 7 - 21). 3. Hindpaw swelling (days 3, 7, 11, 14, 17, 21) and nociception (days 15 and 21) were measured. On day 22 rats were sacrificed, draining lymph nodes were removed and T cells isolated. In vitro proliferation of T cells following stimulation with concanavalin A (0.5 - 5 microg ml(-1)) was measured using a tritiated thymidine incorporation assay. IL-2 receptor expression on T cells was measured by FACS analysis. 4. Naproxen and NO-naproxen showed similar activity in reducing oedema formation in the non-injected (controlateral) hindpaw. Both drugs showed anti-nociceptive effect. NO-naproxen was anti-nociceptive at a dose of 4.5 mg kg(-1) while naproxen showed the same extent of inhibition only at a dose of 10 mg kg(-1). 5. T cells were isolated and characterized by FACS analysis. Stimulation of isolated T cells with concanavallin A in vitro caused a significant increase in thymidine uptake. NO-naproxen at a dose of 4.5 mg kg(-1) inhibited T cell proliferation to the same extent as 10 mg kg(-1) of naproxen. 6. Inhibition of T cell proliferation was well correlated with reduced IL-2 receptor expression on T cells. In addition, NO-naproxen reduced both IL-1beta and TNFalpha plasma levels whilst naproxen reduced IL-1beta levels only. 7. In conclusion, both naproxen and NO-naproxen reduce inflammation and nociception associated with arthritis. In addition NO-naproxen interferes to a larger extent with cellular mechanism involved in T cell activation in rat adjuvant arthritis indicating that introduction of the NO moiety in the naproxen structure increases the effect at the level of the immune system.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Arthritis, Experimental / immunology
  • Arthritis, Experimental / physiopathology
  • Arthritis, Experimental / prevention & control*
  • Dose-Response Relationship, Drug
  • Edema / prevention & control
  • Flow Cytometry
  • Hindlimb
  • Inflammation / prevention & control*
  • Interleukin-1 / blood
  • Male
  • Naproxen / analogs & derivatives*
  • Naproxen / pharmacology
  • Nitric Oxide / pharmacology*
  • Nociceptors / drug effects*
  • Pain / prevention & control
  • Pain Measurement
  • Rats
  • Rats, Inbred Lew
  • Receptors, Interleukin-2 / drug effects
  • Receptors, Interleukin-2 / metabolism
  • T-Lymphocytes / drug effects*
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Thymidine / metabolism
  • Time Factors
  • Tumor Necrosis Factor-alpha / drug effects
  • Tumor Necrosis Factor-alpha / metabolism


  • Anti-Inflammatory Agents, Non-Steroidal
  • Interleukin-1
  • Receptors, Interleukin-2
  • Tumor Necrosis Factor-alpha
  • naproxen-n-butyl nitrate
  • Nitric Oxide
  • Naproxen
  • Thymidine