title: NO-naproxen modulates inflammation, nociception and downregulates T cell response in rat Freund's adjuvant arthritis.
abstract: 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.
authors.affiliation: Dipartimento di Farmacologia Sperimentale, Università degli Studi di Napoli - Federico II, Napoli, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Cicala
authors.forename: A
authors.initials: A
authors.lastname: Ianaro
authors.forename: S
authors.initials: S
authors.lastname: Fiorucci
authors.forename: A
authors.initials: A
authors.lastname: Calignano
authors.forename: M
authors.initials: M
authors.lastname: Bucci
authors.forename: R
authors.initials: R
authors.lastname: Gerli
authors.forename: L
authors.initials: L
authors.lastname: Santucci
authors.forename: J L
authors.initials: JL
authors.lastname: Wallace
authors.forename: G
authors.initials: G
authors.lastname: Cirino
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001169:Arthritis, Experimental / Q000276:immunology / Q000503:physiopathology / Q000517:prevention & control*; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000517:prevention & control; D005434:Flow Cytometry; D006614:Hindlimb; D007249:Inflammation / Q000517:prevention & control*; D007375:Interleukin-1 / Q000097:blood; D008297:Male; D009288:Naproxen / Q000031:analogs & derivatives* / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology*; D009619:Nociceptors / Q000187:drug effects*; D010146:Pain / Q000517:prevention & control; D010147:Pain Measurement; D051381:Rats; D011917:Rats, Inbred Lew; D015375:Receptors, Interleukin-2 / Q000187:drug effects / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007375:Interleukin-1; D015375:Receptors, Interleukin-2; D014409:Tumor Necrosis Factor-alpha; C111751:naproxen-n-butyl nitrate; D009569:Nitric Oxide; D009288:Naproxen; D013936:Thymidine