Intestinal anti-inflammatory activity of morin on chronic experimental colitis in the rat.
BACKGROUND
Morin, a bioflavonoid with antioxidant properties, shows intestinal anti-inflammatory activity in the acute phase of the trinitrobenzenesulphonic acid model of rat colitis.


OBJECTIVE
To assess the anti-inflammatory activity of morin in the chronic stages of trinitrobenzenesulphonic acid-induced rat colitis.


METHODS
Rats were rendered colitic by a single colonic instillation of 30 mg of the hapten trinitrobenzenesulphonic acid dissolved in 0.25 mL of 50% ethanol. A group of colitic animals was given morin orally at doses of 25 mg/kg daily. Animals were sacrificed every week for 4 weeks. Colonic damage was evaluated macroscopically and microscopically. Different biochemical markers of colonic inflammation were also assayed, including myeloperoxidase activity, leukotriene B4 and interleukin-1beta synthesis, glutathione and malonyldialdehyde levels and nitric oxide synthase activity.


RESULTS
The administration of morin facilitated tissue recovery during the 4 weeks following colonic insult with trinitrobenzenesulphonic acid, as demonstrated macroscopically and microscopically, as well as biochemically by a reduction in myeloperoxidase activity. The intestinal anti-inflammatory effect of morin was accompanied by a significant reduction in colonic leukotriene B4 and interleukin-1beta levels, improvement in colonic oxidative stress and inhibition of colonic nitric oxide synthase activity.


CONCLUSIONS
Morin exerts a beneficial anti-inflammatory effect in the chronic phase of trinitrobenzenesulphonic acid-induced rat colitis through the down-regulation of some of the mediators involved in the intestinal inflammatory response, including free radicals, cytokines, leukotriene B4 and nitric oxide.
Gálvez
J
J
Department of Pharmacology, School of Pharmacy, University of Granada, Granada, Spain. jgalvez@platon.ugr.es
Coelho
G
G
Crespo
M E
ME
Cruz
T
T
Rodríguez-Cabezas
M E
ME
Concha
A
A
Gonzalez
M
M
Zarzuelo
A
A
D000284:Administration, Oral; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D000975:Antioxidants / Q000627:therapeutic use*; D002908:Chronic Disease; D003092:Colitis / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D005419:Flavonoids / Q000494:pharmacology / Q000627:therapeutic use*; D007375:Interleukin-1 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects*; D007975:Leukotriene B4 / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014302:Trinitrobenzenesulfonic Acid / Q000633:toxicity; D047309:Flavones
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D005419:Flavonoids; D007375:Interleukin-1; D007975:Leukotriene B4; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D009195:Peroxidase; D014302:Trinitrobenzenesulfonic Acid; C008548:morin; D047309:Flavones