Melatonin reduces bacterial translocation and apoptosis in trinitrobenzene sulphonic acid-induced colitis of rats

AIM： To investigate the effects of exogenous melatonin on bacterial translocation and apoptosis in a rat ulcerati-ve colitis model. METHODS： Rats were randomly assigned to three groups： groupⅠ： control, group Ⅱ： experimental colitis, group Ⅲ： colitis plus melatonin treatment. On d 11 after colitis, plasma tumor necrosis factor-α, portal blood endotoxin levels, colon tissue myeloperoxidase and caspase-3 activity were measured. Bacterial translocation was quantified by blood, lymph node, liver and spleen culture. RESULTS： We observed a significantly reduced inciden-ce of bacterial translocation to the liver, spleen, mesen-teric lymph nodes, portal and systemic blood in animals treated with melatonin. Treatment with melatonin signifi-cantly decreased the caspase-3 activity in colonic tissues compared to that in trinitrobenzene sulphonic acid-trea-ted rats （16.11 ± 2.46 vs 32.97 ± 3.91, P 〈 0.01）. CONCLUSION： Melatonin has a protective effect on ba-cterial translocation and apoptosis.