Markedly reduced toxicity of a hydrogen sulphide-releasing derivative of naproxen (ATB-346).
OBJECTIVE
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].


METHODS
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.


RESULTS
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.


CONCLUSIONS
ATB-346 exhibits anti-inflammatory properties similar to naproxen, but with substantially reduced gastrointestinal toxicity.
Farncombe Family Digestive Health Research Institute, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada. jwalla@mcmaster.ca
John L
JL
Wallace
Giuseppe
G
Caliendo
Vincenzo
V
Santagada
Giuseppe
G
Cirino
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects* / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use; D001169:Arthritis, Experimental / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D051545:Cyclooxygenase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis; D005753:Gastric Mucosa / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D006862:Hydrogen Sulfide / Q000378:metabolism*; D006973:Hypertension / Q000201:enzymology / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D007421:Intestine, Small / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051379:Mice; D015394:Molecular Structure; D009288:Naproxen / Q000009:adverse effects* / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D013276:Stomach Ulcer / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism
C550692:2-(6-methoxy-napthalen-2-yl)-propionic acid 4-thiocarbamoyl-phenyl ester; D000894:Anti-Inflammatory Agents, Non-Steroidal; D009288:Naproxen; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015232:Dinoprostone; D006862:Hydrogen Sulfide