Immunosuppressive effect of emodin on acute rejection after orthotopic liver transplantation in rats

Aim: A few reports have shown that emodin has immunosuppressive effect. This study was aimed to verify the effect of emodin on acute rejection in the early stage after hepatic allograft operation. Methods: The experiment was performed at the Laboratory of Hepatobiliary Surgery, First Affiliated Hospital, Xi'an Jiaotong University from January 2004 to February 2005. SD→Wistar rats were selected to establish orthotopic liver transplantation models (n=80). These rats were randomized into 4 groups with 20 in each group. Rats in the model control group, emodin group, ciclosporin A group and ciclosporin A plus emodin group were intraperitoneally treated with 9 g/L saline, 1.5 mg/kg per day emodin, 3 mg/kg per day ciclosporin A and 3 mg/kg ciclosporin A plus 1.5 mg/kg emodin per day respectively. General conditions of rats were observed after operation. Ten rats in each group were killed 7 days after transplantation. Hepatic samples and serum were collected to observe the intensity of acute rejection in liver tissue, expression of Fractalkine(Fkn), levels of albumin (ALB) and alanine aminotransferase (ALT) in serum. The rest rats in each group were fed and continued to give different drugs or vehicle buffer until they were died and the mean of survival time were recorded. Results: Seventeen rats in the model control group, 18 in the emodin group, 18 in the ciclosporin A group and 18 in the ciclosporin A plus emodin group. 1 Compared with the model control group, the mean survival time was significantly longer in other groups (P < 0.05), and the mean survival time was the longest in the ciclosporin A plus emodin group. 2 Compared with the model control group, on the 7th day after transplantation, the severity of acute rejection was remarkably lower in the other groups (P < 0.05), but ALB level was obviously increased and ALT level was markedly decreased (P < 0.05). The expression of Fkn in liver tissue was significantly decreased (P < 0.05), especially in the ciclosporin A plus emodin group. Conclusion: Emodin can inhibit the severity of rat hepatic allograft acute rejection, and has synergistic effect with ciclosporin A.