Gastric healing effect of melatonin against different gastroinvasive agents in cholestatic rats.
OBJECTIVE
The frequency of gastrointestinal ulceration is higher in jaundiced patients than in healthy population. The aim of this study was to assess the effect of pretreatment with melatonin, a potent scavenger of reactive oxygen species, on stress-induced gastric ulcers of cholestatic rats.


METHODS
Cholestasis was induced by surgical ligation of bile-duct and sham-operated rats served as sham animals. The animals received saline or melatonin (1, 3 or 10mg/kg) before stress induction. Three different types of gastroinvasive agents including ethanol, indomethacin or water immersion were used as stress agents to induce gastric ulceration.


RESULTS
Gastric mucosal damage induced by different gastroinvasive agents was significantly greater in bile-duct-ligated rats than in sham ones. Melatonin was protective against ethanol-, indomethacin- and water immersion-induced gastric damage in bile-duct-ligated and sham rats, dose-dependently, but the protective effect of melatonin was greater in cholestatic rats than sham rats in all three different series of experiments.


CONCLUSIONS
In conclusion, pretreatment of rats with melatonin protected gastric mucosa of cholestatic rats more effectively than the sham ones possibly by a mechanism involving the scavenging of free radicals.
Moezi
Leila
L
Department of Pharmacology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Nasiripoor
Somaye
S
Mohajer
Vida
V
Maghsoodi
Mona
M
Samini
Morteza
M
Dehpour
Ahmad R
AR