Background: Recent evidences show that sirtinol possesses anti-inflammatory properties and protective effects after shocklike states, but the mechanism of these effects remains unknown. Akt (also known as protein kinase B) exerts anti-inflammatory effects in injury. The aim of this study was to investigate whether Akt plays any role in the sirtinol-mediated attenuation of hepatic injury after trauma hemorrhage.
Methods: Male Sprague-Dawley rats underwent trauma hemorrhage (mean blood pressure maintained at approximately 35-40 mm Hg for 90 minutes), followed by fluid resuscitation. During resuscitation, a single dose of sirtinol (1 mg/kg i.v.) with and without a PI3K inhibitor wortmannin (1 mg/kg i.v.), wortmannin, or vehicle was administered. Plasma alanine aminotransferase with aspartate aminotransferase (AST) concentrations and various hepatic parameters were measured (n = 8 rats per group) at 24 h after resuscitation. One-way analysis of variance and Tukey testing were used for statistical analysis.
Results: Trauma hemorrhage increased hepatic myeloperoxidase activity, intercellular adhesion molecule-1 (ICAM-1) and interleukin-6 levels, and plasma alanine aminotransferase and aspartate aminotransferase concentrations. These parameters were significantly improved in the sirtinol-treated rats subjected to trauma hemorrhage. Sirtinol treatment also increased hepatic phospho-Akt expression compared with vehicle-treated trauma-hemorrhaged rats. The coadministration of wortmannin with sirtinol abolished the sirtinol-induced beneficial effects on the above parameters and hepatic injury.
Conclusion: These results suggest the protective effect of sirtinol administration on the alleviation of hepatic injury after trauma hemorrhage, which is, at least in part, through Akt-dependent pathway.