Antioxidant and mitochondrial protective effects of silibinin in cold preservation-warm reperfusion liver injury

Aim of the study: Silybum marianum (milk thistle) is a Mediterranean plant that has been used since Greco-Roman times to treat liver ailments. Silibinin, the most active hepatoprotective constituent of the plant's seed, possesses antioxidant and anti-inflammatory properties. We thus assessed its protective potential in liver transplantation injury.

Materials and methods: Rat livers were isolated and preserved during 24h at 4 degrees C in University of Wisconsin (UW) solution alone (control), UW containing 100 microM silibinin or UW containing vehicle (ethanol). Livers were then reperfused at 37 degrees C for 1h with Krebs-Henseleit solution supplemented with 20% erythrocytes.

Results: Compared to control, cold preservation and warm reperfusion promoted lipid peroxidation (+40%) and superoxide anion generation (+147%), while attenuating reduced glutathione (-23%), mitochondrial ATP content (-57%) and respiratory control ratio (RCR; -37%). Preservation done in presence of silibinin improved parameters affected by preservation and reperfusion. In fact, silibinin promoted an increase of ATP and RCR by, respectively, 39 and 16% and decreased oxidative stress to values observed in livers never preserved nor perfused.

Conclusions: In conclusion, silibinin shows promise in protecting the liver from cold preservation/warm reperfusion damages. Moreover our study suggests that concepts of traditional medicine have the potential to be transposed successfully in the context of modern medical interventions such as liver transplantation surgery.