Bear bile inhibits the immunosuppression activity of hepatic stellate cells in vivo.

Background/aims: In the injured liver, hepatic stellate cells (HSCs) induce immunosuppression activity and thus participate in the pathogenesis of liver disease, including HCC. Therefore, finding new drugs to inhibit their immunosuppression activity is necessary. This study tests whether bear bile can affect the immunosuppression activities of HSCs.

Methodology: The mice were gavaged with bear bile for 4 weeks. The expression of HSCs was detected through desmin and ±-smooth muscle antibody immunohistochemistry. HSCs were isolated from these mice liver and then cultured with T cells in a mixed leukocyte reaction for 3 days. Stellate cell surface makers, T-cell apoptosis, regulatory T cells and the ability of T cells to kill hepatocellular carcinoma were determined via flow cytometry. Cytokines were determined by a mouse cytokine array panel and T-cell proliferation was determined through a BrdU kit.

Results: Bear bile decreased HSCs and their surface molecules, and affected cytokine secretion. Interestingly, HSCs from the mice gavaged with bear bile promoted T-cell proliferation, inhibited T-cell apoptosis, decreased CD4+CD25+Foxp3+ regulatory T cells and enhanced the activation of T cells killing hepatocellular carcinoma.

Conclusions: Bear bile can inhibit the immunosuppression activity of HSCs and enhance immune response especial anti-tumor immune response.