The Effect of Silibinin on the Expression of TLR7, ISG15, and SOCS1 in Peripheral Blood Mononuclear Cells of Hepatitis C Infected Patients in Comparison with Interferon-α

Silibinin (silibinin A) is the most active silymarin component, which acts both as a hepatoprotective [1] and an antiviral agent. The present study investigated the silibinin effect on IFN-related innate immune genes in PBMCs from HCV-infected patients.

22 chronic HCV patients, including 10 IFN responders and 12 non-responders, were included. Their isolated PBMCs were treated for 6 hours in the presence of silibinin, IFN-α, or their combination. The transcription level of TLR7, ISG15, and SOCS1 genes was compared using real-time PCR.

Our result showed that IFN-α induced a significant up-regulation of TLR7 and ISG15 in PBMCs of both responder and non-responder groups. Nevertheless, the SOCS1 gene was not significantly changed in the non-responder group (P=0.32). The combination of IFNα- and silibinin showed a similar pattern to IFN-α alone. By itself, silibinin did not leave a significant change on the expression level of the studied genes.

The results indicated that silibinin did not enhance or suppress the expression level of TLR7, ISG15, and SOCS1 genes.  Therefore, it has been suggested that its anti-inflammatory role might be devoid of IFN pathways.