Reperfusion injury remains one of the major problems in transplantation. Free radicals and disturbance of microcirculation are the supposed main contributors. Recent evidence shows that Danshen, a traditional Chinese drug used in vascular diseases, can scavenge radicals and improve microcirculation. This study investigates its effect on liver transplantation (LTx). Before organ recovery, female Sprague-Dawley rats (210-240 g) received intravenous Danshen or the same volume of Ringer solution as control. LTx was performed after 1 h of cold storage. Microperfusion, leukocyte-endothelium interaction and latex-bead phagocytosis were evaluated with in vivo microscopy. Survival, transaminases and histology were assessed. Immunohistology was used for TNF-alpha levels. anova and Fisher's exact test were employed for statistical analyses as appropriate. Survival increased from 60% in controls to 100% (P < 0.05). AST and LDH decreased from 3969 +/- 1255 U/l and 15444 +/- 5148 U/l in controls to 1236 +/- 410 U/l and 5039 +/- 1594 U/l, respectively (P < 0.05). In vivo microscopy revealed decreased leukocyte-adherence and increased blood flow velocity in sinusoidal zones after administration of Danshen (P < 0.05), while latex-bead phagocytosis was found in 60% of controls (P < 0.05). The TNF-alpha index decreased from 2.08 +/- 0.09 in controls to 1.09 +/- 0.09 (P < 0.05). This study clearly demonstrates hepatoprotective effects after experimental LTx, which can be explained via anti-oxidative effects, improved microcirculation and decreased Kupffer cell activation.