atb-346 and Stomach-Ulcer

Mechanisms of gastric defence under conditions of combined influence of acute stress and non-steroidal anti-inflammatory drugs (NSAIDs) are still poorly studied. The aim of this study was to explore the effects of different types of NSAIDs (naproxen, celecoxib and ATB-346) in producing experimental gastric lesions (induced by water-restraint stress (WRS) or by epinephrine (EPN) injection) and to determine the role of lipid peroxidation and the nitric oxide (NO) system in the pathogenesis of the damage. Male rats were used (eight per group) in this work. The NSAIDs were all administered at a dose 10 mg kg(-1) 30 min prior to WRS or EPN injection. Administration of naproxen to the control rats caused development of gastric lesions, whereas administration of a hydrogen sulfide (H2S)-releasing NSAID (ATB-346) or a selective cyclooxygenase-2 inhibitor (celecoxib) did not cause gastric damage. In contrast, lipid peroxidation processes were enhanced in all groups as was the activity of NO synthase (NOS). Pretreatment with naproxen in the WRS model caused an increase in severity of damage and a decrease in NOS activity. ATB-346 displayed beneficial effects, manifested by a decrease in the area of gastric damage, but parameters of lipid peroxidation and the NOS system did not differ substantially from those in the group treated with naproxen. Administration of different NSAIDs under conditions of EPN-induced gastric damage resulted in the decrease in NOS activity and lipid peroxidation. None of the tested NSAIDs exacerbated EPN-induced gastric mucosal injury; indeed, they all reduced the extent of damage.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Biomarkers; Celecoxib; Disease Models, Animal; Epinephrine; Gastric Mucosa; Hydrogen Sulfide; Lipid Peroxidation; Male; Naproxen; Nitric Oxide; Nitric Oxide Synthase; Pyrazoles; Rats, Wistar; Restraint, Physical; Severity of Illness Index; Stomach Ulcer; Stress, Psychological; Sulfonamides

Hydrogen sulphide is an important mediator of gastric mucosal defence. The use of non-steroidal anti-inflammatory drugs continues to be limited by their toxicity, particularly in the upper gastrointestinal tract. We evaluated the gastrointestinal safety and anti-inflammatory efficacy of a novel hydrogen sulphide-releasing derivative of naproxen, ATB-346 [2-(6-methoxy-napthalen-2-yl)-propionic acid 4-thiocarbamoyl-phenyl ester].. The ability of ATB-346 versus naproxen to cause gastric damage was evaluated in healthy rats and in rats with compromised gastric mucosal defence. Effects on the small intestine and on the healing of ulcers were also assessed. The ability of ATB-346 to inhibit cyclooxygenase-1 and 2 and to reduce inflammation in vivo was also evaluated.. ATB-346 suppressed gastric prostaglandin E(2) synthesis as effectively as naproxen, but produced negligible damage in the stomach and intestine. In situations in which the gastric mucosa was rendered significantly more susceptible to naproxen-induced damage (e.g. ablation of sensory afferent nerves, inhibition of endogenous nitric oxide or hydrogen sulphide synthesis, co-administration with aspirin, antagonism of K(IR)6.x channels), ATB-346 did not cause significant damage. Unlike naproxen and celecoxib, ATB-346 accelerated healing of pre-existing gastric ulcers. In a mouse airpouch model, ATB-346 suppressed cyclooxygenase-2 activity and inhibited leukocyte infiltration more effectively than naproxen. ATB-346 was as effective as naproxen in adjuvant-induced arthritis in rats, with a more rapid onset of activity. Unlike naproxen, ATB-346 did not elevate blood pressure in hypertensive rats.. ATB-346 exhibits anti-inflammatory properties similar to naproxen, but with substantially reduced gastrointestinal toxicity.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Experimental; Blood Pressure; Cyclooxygenase 1; Cyclooxygenase 2; Dinoprostone; Gastric Mucosa; Hydrogen Sulfide; Hypertension; Intestinal Mucosa; Intestine, Small; Male; Mice; Molecular Structure; Naproxen; Rats; Rats, Wistar; Stomach Ulcer