Comparison between the effects of selenomethionine and S-adenosylmethionine in preventing cholestasis-induced rat liver damage.

We aimed to evaluate whether two methionine-related compounds, S-adenosylmethionine (SAM), and selenomethionine (SM), could lessen liver damage induced by regurgitated bile in a model of rat bile duct ligation (BDL). Hepatoprotective potentials of S-adenosylmethionine and selenomethionine were estimated based on the changes of serum liver damage parameters (aminotransferases, alkaline phosphatase, gamma-glutamyltranspeptidase and lactate dehydrogenase activity, and bilirubin concentration), tissue oxidative [xanthine oxidase (XO) and catalase activity, thiobarbituric acid reactive substances (TBARS) levels] and inflammatory [tumor necrosis factor-alfa (TNF-α) concentration] parameters, and morphological liver tissue alterations that follow cholestasis. The treatment regimens proved themselves able to prevent significant liver damage induced by cholestasis. Both SAM and SM decreased XO activity and TBARS levels and increased catalase activity, while only SM significantly reduced TNF-α concentration. Morphological changes related to bile-induced liver damage were also found to be partially diminished by SAM and SM. In view of the mechanisms of action of the two tested methionine-derived compounds, one might say that SM predominantly acted as an antioxidant, while SAM exerted its activity by potentially modulating different gene expression and protein structures. It is also worth mentioning that this is the first study (to the best of our knowledge) that dealt with the effects of SM on BDL-induced liver injury in rats and of the findings that speak favorably of this powerful antioxidant.